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plants

How Do Palm Trees Withstand Hurricanes? by Laura Geggel

Diverse Forests Are Better at Accumulating Carbon by Catherine Offord

Why Dandelion Seeds Are So Good At Floating by Bill Andrews

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Why Dandelion Seeds Are So Good At Floating

Dandelion blowing may be about as close to a universal experience as there is. Kids and adults alike delight in huffing the white fluffy seeds from a dried sample of Taraxacum officinale, and watching them fly away.

But as with all things in nature, it only happens that way because it works. Dandelion seeds can travel for miles before setting down, making them particularly efficient fliers. And scientists didn’t really know why. Other plant seeds, such as maples, use more of a wing-like design to get airborne, so there must be a reason the brushy, plumed seeds worked for dandelions.

Well, according to a paper published Wednesday in Nature, a team of physicists in Scotland have found that reason: a special kind of air bubble that forms above each seed, which helps keep it aloft longer. It’s literally a new kind of flying, and it doesn’t just help scientists understand dandelions better — it opens up a new avenue for exploring all kinds of movement in the air and beyond.

Just Dandy

The first part of the study was simple enough, just studying the design of a dandelion seed with ultra-precise X-ray scans and regular light microscopy. The authors dutifully report that each pappus, the bristly head of a seed, contains 100 rod-like filaments on average, each about 7.4 mm long and 16.3 μm thick. They also found the porosity of the pappus is nearly 92 percent, meaning it’s mostly empty space up there.

Now the cool part. The team placed dandelion seeds in a vertical wind tunnel which kept them floating indefinitely, effectively hovering at a fixed height. Then, with long-exposure photography and high-speed cameras, they analyzed the behavior of the air as it moved through the bristles of the pappus. That’s when they discovered the air bubble, always trailing a fixed distance downstream (so, above) the seed.

Technically, though, it’s not really a bubble; the authors call it a separated vortex ring (SVR). Instead of just a ball of air, like a true bubble, this vortex is more like a stretched-out donut, very tall with a long thin hole down the middle. As air flows up through the pappus, it hits the outside of the SVR, then gets caught up in the flow and follows it inward, down the hole. It emerges on the bottom end and starts to flow back up again, restarting the cycle.

All this ends up creating a tiny spot of low pressure directly above the floating dandelion seed, slowing its descent through the air.

Dandelion Design

So not only does the pappus of a dandelion seed create this SVR, but the authors determined it’s also perfectly engineered to stabilize the pocket of air. That’s crucial — similar kinds of air bubbles had been theorized before, but scientists had considered them too unstable to actually form in real life. They didn’t reckon with the power of a pappus’ porosity!

By testing their own versions of dandelion seeds with varying designs, the authors saw that dandelion seeds had naturally settled on practically the most efficient means of creating and keeping that crucial SVR going. That 92 percent porosity was the key.

As the authors write, “By uncovering the physics behind the flight of the dandelion, we have discovered a novel type of fluid behaviour around fluid-immersed bodies.” (The term “fluids” refers to both gases and liquids, which always makes me wonder why physicians aren’t more specific.) Basically, the team discovered a brand-new method of flight that nature’s been exploiting since forever.

Similar structures are “commonplace in the biological world,” they write, so the finding might also help scientists understand how other plants and animals get around, both in the air and underwater. And there’s a chance this could also help engineers come up with better tools to navigate those fluids, too.

Something to consider, perhaps, the next time you find yourself blowing apart a dandelion, scattering its seeds to the wind.

Dandelions are known for their seeds; the way that they look and float in the wind. Dandelion seeds can float for long distances on end, that allow them to grow kilometres away from the original plant. For years, scientists were unsure on how the seeds were able to fly such a distance until physicists in Scotland cracked the code. The pappus, the bristled region above the seed, held thin rod-like filaments, with a porosity of 92%. The physicists then put the seeds in a vertical tube with a wind flow, keeping the seeds hovering in the same spot. They discovered an air bubble forms above the seed, keeping it adrift longer. The bubble, formally called a separated vortex ring (SVR) creates an area of low pressure, slowing the plummet.

Plants have specialized structures with distinct functions that enable them to respond and adapt to their environment.

The dandelion has specialized structures that allow the species to thrive and reproduce. The seeds can travel long distances to where there may be more resources available and less competition. This gives them a higher chance of surviving. 

Reference

Andrews, B. (2018, October 18). Why Dandelion Seeds Are So Good At Floating. Retrieved from http://blogs.discovermagazine.com/d-brief/2018/10/18/dandelion-seeds-fly/

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Diverse Forests Are Better at Accumulating Carbon

A higher species richness could boost plant communities’ ability to mitigate climate change, a study suggests.

Y. Huang et al., “Impacts of species richness on productivity in a large-scale subtropical forest experiment,” Science, 362:80–83, 2018.

Plants can help mitigate climate change by removing and storing carbon from the atmosphere. Bernhard Schmid, an ecologist and environmental scientist at the University of Zurich, and others have published observational research suggesting that, in forests, higher species richness is associated with higher carbon sequestration. But it wasn’t clear whether the relationship was causal, Schmid says.

To explore the issue experimentally, Schmid and colleagues in Germany and China enlisted the help of farmers in southeast China’s Jiangxi Province to plant nearly 160,000 trees on small plots such that each plot contained between 1 and 16 species. After eight years, the 16-species plots had accumulated more than twice the amount of carbon that the average single-species plots had. Combined with previous findings, the results provide “the most convincing evidence so far that forests that are more diverse indeed are more productive and do store more carbon,” Schmid says.

“It’s a nice paper,” says Martin Lukac, a forest ecologist at the University of Reading in the UK who was not involved in the work. “I wish we had more studies like this.” But he notes that certain single-species plots—those planted with commercial conifers—accumulated about as much carbon as 16-species plots did. Although the authors acknowledge this result in their paper, they could have explained more clearly that multispecies forests have the added advantage of being more ecologically resilient to climate change than monocultures, he says.

A longer-term study would help clarify the biodiversity-carbon link, says Lukac, although as the trees grow larger, overcrowding could contribute confounding effects. Schmid says his team would like to continue the project. In the meantime, he hopes that land managers and others in charge of reforestation will accept that “it really makes sense to plant diverse forest.”

Plants have the ability to remove and store carbon from the atmosphere, alleviating climate change. Scientists have found research which indicate the benefits of forests with a diverse range of vegetation. I more diverse forests, the carbon in the atmosphere is more effectively removed, though it is unclear whether this relationship between the diversification and carbon content is causation or correlation. Researchers in China and Germany planted almost 160 000 trees with the help of Chinese farmers in southeast China. Each plot contained 1-16 species of trees and the experiment lasted for 8 years. At the end of the 8 year period, the data showed that the plots with 16 species collected as much as twice as more carbon as single species plots. Diverse forests also have the added benefit of being more resilient to climate change than mono cultures. However, Martin Lukac, an ecologist, states that it should be noted that certain species can affect the results. For example, certain commercial conifers removed the same amount of carbon as 16 species plots.

Plant variety is critical to the survival and sustainability of ecosystems.

This article discusses the benefits of having a diverse forest versus a monoculture. The more diverse forests are more environmentally beneficial, as they have greater ability to be a carbon sink. Also, if there is a disease that attacks a certain species, not all of the trees will succumb to it. 

Reference

Offord, C. (2018, December 1). Diverse Forests Are Better at Accumulating Carbon. Retrieved from https://www.the-scientist.com/the-literature/diverse-forests-are-better-at-accumulating-carbon-65109

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How Do Palm Trees Withstand Hurricanes?

Trees generally snap, or at least lose a few branches, when faced with hurricane-strength winds. Not palm trees. These staples of the tropics typically bend during gusty weather.

How does the mighty palm usually stay standing, swaying — sometimes violently — in storms?

For starters, unlike traditional trees, palm trees are not made of wood. "Instead, you'll find a jumble of spongy tissue, scattered instead of arranged" inside a palm, geochemist Hope Jahren wrote in her autobiography "Lab Girl" (Vintage, 2016). [Are Trees Vegetarian?]

Most trees lay down rings as they grow every year. But not the palm tree; some of its cells are malleable, and others can easily flex and then return to their original position.

"[Its] lack of conventional structure is what gives the palm its flexibility and makes it supremely adapted … to the gentle island breezes that periodically coalesce into ruthless hurricanes," Jahren wrote in her book.

This arrangement has helped the palm tree flourish in warm and windy tropical areas the world over. There are 188 known genuses of palm, and 2,585 species, said Judy Jernstedt, a professor of plant sciences at the University of California, Davis.

"I think that suggests that it's a successful growth form, and they've been successful in the environmental niches that they've occupied," Jernstedt said.

However, not all palms are alike. A palm planted in a new area might not fare as well as a palm in its native home, Jernstedt said. Moreover, if the ground is wet — from a hurricane surge, for instance — that could weaken the ground where the palm's roots extend and make it easier for powerful winds to uproot the tree, she said.

While the palm tree is technically a tree, palms are actually more closely related to grass, corn and rice than they are to other trees, Jernstedt said. They're also quite old. Palms belong to the Arecaceae family, a group that emerged about 100 million years ago, during the Cretaceous period, when nonavian dinosaurs still roamed the Earth, according to the Angiosperm Phylogeny website, run by Peter Stevens, a professor of biology at the University of Missouri-St. Louis.

Palm trees live in areas where winds are so strong that most other trees snap in two, but a special characteristic of palm trees is that they do not. Instead of wood, they are made of spongy tissue “scattered instead of arranged”. Lacking the trademark wood found in most trees, they also lack the rings that trees put on every year. This is what makes palm trees well suited for high winds; the unconventional structure gives them the ability to bend and stretch under pressure. However, other conditions also affect their ability to survive. Wet dirt underneath the tree would compromise it’s hold on the earth, allowing strong winds from a hurricane to easily uproot them. Palm trees are so successful, they are found all over the world in tropical areas, such as Hawaii, with over 2 000 species known to man. Whilst technically a tree, they are closer to grass, corn, and rice.

Plants have specialized structures with distinct functions that enable them to respond and adapt to their environment.

The palm tree has developed its own characteristics in order to survive in its environment. It developed specific structures, such as the tissue instead of wood, that makes it suited for the habitat.

References

Geggel, L. (2017, September 12). How Do Palm Trees Withstand Hurricanes? Retrieved from https://www.livescience.com/60393-why-palm-trees-are-so-flexible.html

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CRISPR bombshell: Chinese researcher claims to have created gene-edited twins

Genetic and genomic research can have social and environmental implications.HONG KONG, CHINA—On the eve of an international summit here on genome editing, a Chinese researcher has shocked many by claiming to have altered the genomes of twin baby girls born this month in a way that will pass the modification on to future generations. The alteration is intended to make the children’s cells resistant to infection by HIV, says the scientist, He Jiankui of the Southern University of Science and Technology in Shenzhen, China.

The claim—yet to be reported in a scientific paper—initiated a firestorm of criticism today, with some scientists and bioethicists calling the work “premature,” “ethically problematic,” and even “monstrous.” The Chinese Society for Cell Biology issued a statement calling the research “a serious violation of the Chinese government’s laws and regulations and the consensus of the Chinese scientific community.” And He’s university issued a statement saying it has launched an investigation into the research, which it says may “seriously violate academic ethics and academic norms.”

Other scientists, meanwhile, asked to see details of the experiment and its justification before passing judgment.

He told The Associated Press (AP) that he altered embryos for seven couples during fertility treatments, with one pregnancy resulting thus far. In each case, the father was infected with HIV; the mothers were HIV-negative. He’s goal was to introduce a rare, natural genetic variation that makes it more difficult for HIV to infect its favorite target, white blood cells. Specifically, He deleted a region of a receptor on the surface of white blood cells known as CCR5 using the revolutionary genome-editing technique called CRISPR-Cas9.

According to the AP report, He was not trying to prevent transmission of HIV from the father’s sperm to the embryo, a highly unlikely event. The risk of transmission drops even lower when the sperm is washed before insemination through in vitro fertilization, as occurred here. Rather, He said he wanted to protect the babies from infection later in life.

The International Summit on Human Genome Editing begins here on Tuesday and many researchers, ethicists, and policymakers attending the meeting first learned of He’s claim through media reports. Organizers of the conference told reporters at a pre-event briefing they were awaiting further details.

Scientists are investigating the use of CRISPR-Cas9 as a treatment for many genetic diseases, such as muscular dystrophy and sickle cell anemia. One long-running study in HIV-infected adults has crippled CCR5 with another genome-editing technology, and a similar study is underway in China with CRISPR. But these cases involved gene editing of so-called somatic cells that are not passed on to the patient’s children. He reportedly went a step further, altering the genome in early stage embryos, which would affect sperm and eggs—the germ line—and make the change heritable. Such work is effectively barred in the United States and many other countries. Whether it fits within China’s regulatory environment is not clear.

He is scheduled to speak at the summit on gene editing on Wednesday, but organizers were unsure whether he planned to discuss his experiment. He put a series of videos on YouTube to justify the experiment and explain how it was done. He also invited viewers to send comments to his lab and to the two babies, named Lula and Nana.

Yet many scientists say the experiment was premature and the potential benefits not worth the risk. “The underlying purpose of doing the experiment was obviously to show that they could do gene editing on an embryo, but the purpose for the party involved does not make any sense,” says Anthony Fauci, an HIV/AIDS researcher who heads the U.S. National Institute of Allergy and Infectious Diseases in Bethesda, Maryland. “There are so many ways to adequately, efficiently, and definitively protect yourself against HIV that the thought of editing the genes of an embryo to get to an effect that you could easily do in so many other ways in my mind is unethical.”

Pablo Tebas, a clinical researcher at the University of Pennsylvania who led a small study that crippled CCR5 in HIV-infected adults using what’s known as zinc finger technology, similarly denounced the embryo alteration. “The experiment is not medically justified,” said Tebas, who noted that CCR5 mutants are not benign as people are more susceptible to serious consequences from West Nile infections. “Hopefully these kids will not have any health problems," he says.

“Gene editing itself is experimental and is still associated with off-target mutations, capable of causing genetic problems early and later in life, including the development of cancer,” Julian Savulescu, an ethicist at the University of Oxford in the United Kingdom, said in a statement released today by the U.K. Science Media Centre. “This experiment exposes healthy normal children to risks of gene editing for no real necessary benefit,” he says. Sarah Chan, a bioethicist at the University of Edinburgh, worries that the premature use of gene editing prior to consideration of social aspects of the work “threatens to jeopardize the relationship between science and society … and might potentially set the global development of valuable therapies back by years.”

CRISPR pioneer Jennifer Doudna of the University of California, Berkeley, notes that the work has not been published and urged caution in a statement released today. However, "Assuming that independent analysis confirms today’s news, this work reinforces the urgent need to confine the use of gene editing in human embryos to settings where a clear unmet medical need exists, and where no other medical approach is a viable option, as recommended by the National Academy of Sciences,” Doudna wrote.

Apparently anticipating the criticism, He boldly proclaimed in one of this videos that his group has reflected deeply on how to help families facing risks of genetic diseases. “We believe ethics are on our side of history,” says He, who calls the term “designer babies” an epithet.

Richard Hynes, a cancer researcher at the Massachusetts Institute of Technology in Cambridge who co-chaired the National Academies of Sciences, Engineering, and Medicine report that Doudna referred to, says it laid out “stringent conditions” that should be met before undertaking genome editing: There had to be a serious, unmet medical need; the effort should be well-monitored and with sufficient follow-up; and there had to be informed consent of the parents.

He adds that the United Kingdom’s Nuffield Council on Bioethics’s report on human genome editing, released in July, reached similar conclusions. “All these questions need to be looked into when we hear what he’s actually done,” Hynes says. Alta Charo, a bioethicist at the University of Wisconsin at Madison, notes that the National Academies report does mention CCR5 as a potential target of gene editing. Whether the current experiment is justified “comes down to a risk-benefit analysis,” she says.

A Chinese researcher claims to have altered the genomes of 2 female twins born in November of 2018. Fellow researchers are shocked and have responded with outrage, calling it unethical and “monstrous”. The Chinese Society for Cell Biology called it “a serious violation of the Chinese government’s laws and regulations and the consensus of the Chinese scientific community.” He Jiankui, the man behind all this, changed the childrens’ code to be more resistant to HIV. He has already altered the embryos of 7 couples, with one resulting in pregnancy, all of the embryos coming from an HIV positive father and an HIV negative mother. His goal is to create a mutation and thus a variation that would delete a region of a receptor on white blood cells, that would effectively make it very difficult for HIV to latch on. He did not intend to prevent transmission from their fathers, rather prevent them from getting the disease in later life. He edited the babies’ genome using a technology called CRISPR-Cas9, which is also used to treat other disorders such as muscular dystrophy. However, instead of editing the somatic cells that would render the trait non-heritable, He Jiankui edited the genome to make the trait heritable. This kind of move is illegal in many countries, however, it is unclear if Chinese regulations were broken. Many scientists have condemned this, saying that it does more harm than good.

Genetic and genomic research can have social and environmental implications.

He Jiankui did his experiment in the name of helping families and individuals in the future, however, he left a mess in the scientific community while doing so. While researchers in today’s time have condemned He’s experiment, it is unsure whether this kind of genetic research is or will be socially and ethically acceptable in the future.

Reference

Normile, D. (2018, November 27). CRISPR bombshell: Chinese researcher claims to have created gene-edited twins. Retrieved from http://www.sciencemag.org/news/2018/11/crispr-bombshell-chinese-researcher-claims-have-created-gene-edited-twins

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23andMe Is Sharing Genetic Data with Drug Giant

The genetics testing company and GlaxoSmithKline are using five million people’s data to develop medical treatments. 

Popular genetics-testing company 23andMe is partnering with drug giant GlaxoSmithKline to use people’s DNA to develop medical treatments, the company announced in a blog post yesterday (July 25).

During the four-year collaboration, the London-based GlaxoSmithKline will use 23andMe’s genetic database to zero in on possible targets and treatments for human disease.

“The goal of the collaboration is to gather insights and discover novel drug targets driving disease progression and develop therapies,” GlaxoSmithKline said in yesterday’s statement, where it also reported it was investing $300 million in 23andMe. [How Do DNA Ancestry Tests Really Work?]

It’s not yet clear which conditions will be investigated during the collaboration, but one example showed how the collaboration might work: the two companies’ previous collaboration on the gene LRRK2, which is linked to some cases of Parkinson’s disease, Forbes reported.

Only about 10,000 of the 1 million Americans with Parkinson’s disease have the disease because of LRRK2. So, GlaxoSmithKline has to test about 100 Parkinson’s patients to find just one potential candidate. However, 23andMe has already provided 250 Parkinson’s patients who have agreed to be re-contacted for GlaxoSmithKline’s clinical trials, which may help the pharmaceutical company develop the drug much faster, Forbes reported.

However, not everybody is on board with 23andMe’s new partnership. If a person’s DNA is used in research, that person should be compensated, said Peter Pitts, president of the Center for Medicine in the Public Interest.

“Are they going to offer rebates to people who opt in, so their customers aren’t paying for the privilege of 23andMe working with a for-profit company in a for-profit research project?” Pitts said to NBC.

In addition, even though 23andMe gets the consent of its customers to use their genetic data, it’s unlikley that most people are aware of this.

“The problem with a lot of these privacy policies and Terms of Service is that no one really reads them,” Tiffany C. Li, a privacy expert and resident fellow at Yale Law School’s Information Society Project, told Tom’s Guide, a Live Science sister site. “You are paying to help the company make money with your data.”

The new collaboration isn’t the first time 23andMe’s vast pool of genetic data has been mined by scientists. The San Francisco startup has already published more than 100 scientific papers based on its customers’ data, according to yesterday’s blog post, by Anne Wojcicki, 23andMe’s co-founder and chief executive. In 2015, the company launched 23andMe Therapeutics, which focuses on developing “novel treatments and cures based on genetic insights from the consented 23andMe community,” Wojcicki wrote.

23andMe has more than 5 million customers worldwide who have had their DNA analyzed for ancestral data. People who would like to close their 23andMe accounts can go here, but the company notes that “any research involving your data that has already been performed or published prior to our receipt of your request will not be reversed, undone, or withdrawn.”

However, once a 23andMe account is closed, any spit samples that a person initially gave consent to be stored “will be discarded,” the company said.

Technology exists that humans can now see what makes up their genetic code. Companies like 23andMe offer their services to anyone willing to pay. The company allows one to see if they are more or less likely for certain traits or diseases. 23andMe are now working with a drug company called GlaxoSmithKline to research diseases linked with genes. However, 23andMe are using clients data and providing it to GlaxoSmithKline without payment to those whose information is being used. Most people are unaware that they have already given consent to this, due to how privacy policies and Terms of Services are written. Many experts are distraught, these people are being used for data and not being reimbursed in any way.

Genetic and genomic research can have social and environmental implications.

Leaks could happen and the data people gave to 23andMe could end up elsewhere for who knows what purposes. This is also an ethical issue. 23andMe has left a massive mark on today’s culture, with many influencers taking sponsorship deals to advertise the service to their audiences, resulting in more people who’s data could be used without their knowledge. 

References

Geggel, L. (2018, July 28). 23andMe Is Sharing Genetic Data with Drug Giant. Retrieved from https://www.scientificamerican.com/article/23andme-is-sharing-genetic-data-with-drug-giant/

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Are We Really Prepared for the Genetic Revolution?

When humans’ genetic information (known as the genome) was mapped 15 years ago, it promised to change the world. Optimists anticipated an era in which all genetic diseases would be eradicated. Pessimists feared widespread genetic discrimination. Neither of these hopes and fears have been realised.

The reason for this is simple: our genome is complex. Being able to locate specific differences in the genome is only a very small part of understanding how these genetic variants actually work to produce the traits we see. Unfortunately, few people understand just how complex genetics really is. And as more and more products and services start to use genetic data, there’s a danger that this lack of understanding could lead people to make some very bad decisions.

At school we are taught that there is a dominant gene for brown eyes and a recessive one for blue. In reality, there are almost no human traits that are passed from generation to generation in such a straightforward way. Most traits, eye colour included, develop under the influence of several genes, each with its own small effect.

What’s more, each gene contributes to many different traits, a concept called pleiotropy. For example, genetic variants associated with autism have also been linked with schizophrenia. When a gene relates to one trait in a positive way (producing a healthy heart, say) but another in a negative way (perhaps increasing the risk of macular degeneration in the eye), it is known as antagonistic pleiotropy.

As computing power has increased, scientists have been able to link many individual molecular differences in DNA with specific human characteristics, including behavioural traits such as educational attainment and psychopathy. Each of these genetic variants only explains a tiny amount of variation in a population. But when all these variants are summed together (giving what’s known as a characteristic’s polygenic score) they begin to explain more and more of the differences we see in the people around us. And with a lack of genetic knowledge, that’s where things start to be misunderstood.

For example, we could sequence the DNA of a newborn child, calculate their polygenic score for academic achievement and use it to predict, with some degree of accuracy, how well they will do in school. Genetic information may be the strongest and most precise predictor of a child’s strengths and weaknesses. Using genetic data could allow us to more effectively personalise education and target resources to those children most in need.

But this would only work if parents, teachers and policymakers have enough understanding of genetics to correctly use the information. Genetic effects can be prevented or enhanced by changing a person’s environment, including by providing educational opportunity and choice. The misplaced view that genetic influences are fixed could lead to a system in which children are permanently separated into grades based on their DNA and not given the right support for their actual abilities.

BETTER MEDICAL KNOWLEDGE

In a medical context, people are likely to be given advice and guidance about genetics by a doctor or other professional. But even with such help, people who have better genetic knowledge will benefit more and will be able to make more informed decisions about their own health, family planning, and health of their relatives. People are already confronted with offers to undergo costly genetic testing and gene-based treatments for cancer. Understanding genetics could help them avoid pursuing treatments that aren’t actually suitable in their case.

It is now possible to edit the human genome directly using a technique called CRISPR. Even though such genetic modification techniques are regulated, the relative simplicity of CRISPR means that biohackers are already using it to edit their own genomes, for example, to enhance muscle tissue or treat HIV.

Such biohacking services are very likely to be made available to buy (even if illegally). But as we know from our explanation of pleiotropy, changing one gene in a positive way could also have catastrophic unintended consequences. Even a broad understanding of this could save would-be biohackers from making a very costly and even potentially fatal mistake.

When we don’t have medical professionals to guide us, we become even more vulnerable to potential genetic misinformation. For example, Marmite recently ran an ad campaign offering a genetic test to see if you either love or hate Marmite, at a cost of £89.99. While witty and whimsical, this campaign also has several problems.

First, Marmite preference, just like any complex trait, is influenced by complex interactions between genes and environments and is far from determined at birth. At best, a test like this can only say that you are more likely to like Marmite, and it will have a great deal of error in that prediction.

Second, the ad campaign shows a young man seemingly “coming out” to his father as a Marmite lover. This apparent analogy to sexual orientation could arguably perpetuate the outdated and dangerous notion of “the gay gene”, or indeed the idea that there is any single gene for complex traits. Having a good level of genetic knowledge will enable people to better question advertising and media campaigns, and potentially save them from wasting their money.

My own research has shown that even the well-educated amongst us have poor genetic knowledge. People are not empowered to make informed decisions or to engage in fair and productive public discussions and to make their voices heard. Accurate information about genetics needs to be widely available and more routinely taught. In particular, it needs to be incorporated into the training of teachers, lawyers and health care professionals who will very soon be faced with genetic information in their day-to-day work.

Years ago, when the technology for mapping the genomes of humans appeared, the world was sure that the new generation of science was upon them. Now, nothing has really changed; genetic diseases have not been completely eliminated from society nor has discrimination based on genetics happened. Few people understand the complexity of genomes and the lack of understanding combined with the push in the economy for services and goods that use genomes could lead to disaster. Genes contribute to more than one trait, sometimes a good and bad trait at the same time (which is called antagonistic pleiotropy). There come problems associated with knowing the genes of an individual, an example in the article is of a child and their academic strengths and weaknesses. Educators and parents may put too much emphasis on the “fixedness” of genetics and fail to recognize the influence of a person’s environment or upbringing. Another problem is the lack of medical knowledge. People are spending large amounts of money to genetics based treatments that may not be effective for them. Services may be available in the future that allow an individual to rewrite the genetic code of their body; this may prove fatal, given the understanding of antagonistic pleiotropy.

Genetic and genomic research can have social and environmental implications.

The author of this article writes about the possible future consequences of gene editing and research, on the social impact it may have on future generations (or lack thereof) and what genetics research means down the road. Chapman emphasizes the importance of understanding and knowledge regarding genetics, the misinformation behind it, and the consequences of being misinformed.

References

Chapman, R. (2018, May 27). Are We Really Prepared for the Genetic Revolution? Retrieved from https://www.scientificamerican.com/article/are-we-really-prepared-for-the-genetic-revolution/

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genetics

Are We Really Prepared for the Genetic Revolution? by Robert Chapman

23andMe Is Sharing Genetic Data with Drug Giant by Laura Geggel

CRISPR bombshell: Chinese researcher claims to have created gene-edited twins by Dennis Normille

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animals

An Island Nation’s Health Experiment: Vaccines Delivered by Drone by Donald McNeil

Can this breath test tell if you have cancer or one of 16 other diseases? by Emanuela Campanella

A Guide to Using Apple Watch’s Heart Rate Features, Including ECG by Lauren Goode

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A Guide to Using Apple Watch’s Heart Rate Features, Including ECG

ONE THING THAT makes smartwatches increasingly valuable is their inclusion of biosensors, little modules that keep tabs on what's happening with your body, whether you're an athlete running a marathon or somebody who just decided to get up off the couch. And one of the most useful health metrics a smartwatch can track is your heart rate. Appleknows this, and, as part of an effort to make the Apple Watch a more alluring accessory for iPhone owners, the company is focusing intently on building advanced heart-rate monitoring into its best-selling wearable.

A software update rolling out today will include an optional app for Apple Watch Series 4 that takes ECG (electrocardiogram) readings through the new device's specially designed sensors. That same software update will allow older Apple Watches without the redesigned sensors to detect irregular heart rhythms. Both of these enhancements are supposed to help wearers identify signs of atrial fibrillation, a condition identified by a rapid or irregular heartbeat that can lead to serious heart complications.

Apple made a splash when it announced these features at its annual hardware event in September, partly because the ECG app had been cleared by the FDA (which, it's worth keeping in mind, is different from FDA approval). But, even if you don't have the latest hardware and can't take advantage of the ECG app, there are plenty of heart-rate tracking features to dive into on the Apple Watch. It's a lot; here's a short guide.

Heartware Limitations

Let's start with the basics: the ECG app and notifications around irregular heart rate rhythms are rolling out as a part of a watchOS update for Apple Watch. The latest software is watchOS 5.1.2. Apple Watch updates can take an extremely long time for such a little gadget—you may wait more than an hour—and at the time of publication, I hadn't installed the update myself yet. My experience with the ECG app was on a loaner watch Apple provided. But hopefully, the update process has improved.

The ECG app will only work on Apple Watch Series 4. That's because that watch has electrodes built into the back of the watch, as well as electrical heart sensors in the watch's crown. Older Apple Watches don't have this.

All Apple Watches, however, do have the same optical heart rate sensors. That means that, with this latest software update, Apple Watch Series 1 and later watches will attempt to track irregular heart rhythms, and therefore will potentially be able detect atrial fibrillation.

How to Use the ECG App

Before you start using the ECG app on the Apple Watch Series 4, you'll have to first go through the onboarding process in the Apple Health app on iPhone. Same with setting up notifications for possible signs of Afib. It requires scooting back and forth between the iPhone's Watch app, the iPhone's Health app, and the Apple Watch itself. But once the setup is done, you shouldn't have to go through it again.

Apple has made a point to say (many times) that the ECG app is not a diagnostic tool; and that it's really not supposed to be used just for kicks. You're supposed to give it a go when you're feeling symptoms like a rapid or skipped heartbeat. Or, you can use it when you get a notification that the watch has detected an especially high or low heart rate, or some other irregularity.

That said, taking an ECG reading is straightforward. You open the ECG app on the Apple Watch, rest your watch-equipped arm somewhere, and press the index finger of your opposite hand against the Apple Watch's crown for 30 seconds. Occasionally, it might say recording stopped due to a poor reading, which happened to me a couple times when the watch's underside wasn't flat against my wrist—so make sure the back of the watch is in full contact with your wrist. The app then shows results right on the watch; for example, it might say it detected a sinus rhythm, which means your heart is beating in a uniform pattern. It also shares the findings with your iPhone's Health app.

So far, in the time that I've been wearing the loaner Apple Watch with the latest software, I haven't received an irregular heart rhythm notification. And there's really no way to "test" whether it's accurate if I don't have the problem it's looking for. Using the ECG app is an active experience. You open the app on Apple Watch and take that 30-second reading. The irregular heart rhythm detection, on the other hand, is a passive thing; you'll only get a notification if the watch detects a problem after taking multiple background readings.

Exercise Your Options

One of the key features to look for on any wrist-based tracker is its ability to measure your spikes in heart rate during intense exercise activities. The Apple Watch has done this since the product's origin, though over time, the company has tweaked the way the device tracks your heart rate during periods of exercise.

The Apple Watch can't diagnose you with anything. It's supposed to point you toward meaningful data and maybe encourage you to act if there are signs something may be wrong.

For example, with the rollout of watchOS 4 in 2017, the Apple Watch starting showing a "Workout Recovery Rate" after an exercise session. This bit of data lets you know how quickly your heart returns to its regular resting rate after a workout. You'll have to actually record the workout on the watch (using the green Workout app) in order to see your recovery rate, though. After that, it's not easy to find. After ending the workout, you have to scroll down through the workout summary and tap on the tiny heart icon, which brings you to the Heart Rate app. Your recovery rate can be found there.

Over the last few years, Apple has also upped the watch's sampling rate—its frequency of heart-rate measurements, which are taken automatically in the background as you go about your business. A software update in September 2016 changed the all-day sample rate from once every ten minutes to once every five minutes. Apple won't share specifics on how the sample rate during exercise routines has changed in this watchOS update, but fitness wearables are often designed to sample heart rate most frequently when you indicate that you're exercising.

Rest(ing) Up

The Apple Watch will also show you your resting heart rate, although my understanding is that Apple's approach is different from heart rate monitors that are designed to be worn overnight. That's the thing about Apple Watch, and one of my biggest quibbles with it: Because its battery only lasts between a day and a day and a half, it's not really meant for tracking your sleep. You can't get an overnight or a first-thing-in-the-morning heart rate reading if your watch is on the charging pad atop your nightstand.

Instead, the watch will sample your heart rate once you're wearing it, and continue to measure it until it has sampled enough to algorithmically determine a resting heart rate reading. Sometimes this means it won't appear until after you've worked out or arrived at work.

All Day Every Day

Even if you're not interacting with your Apple Watch's heart rate features directly, the Watch is periodically taking those background readings. It will record your average resting rate as well as your walking average heart rate. In watchOS 4, it also started recording heart rate variability, or any variation in the time between heartbeats, a few times a day.

And if you just want to check out your current heartbeat from time to time, or compare it to a reading from a pulse oximeter in a doctor's office like I did recently for fun, you can do that by tapping on the heart rate app (a gray app with the red outline of a heart) on the Watch.

Appsolutely Healthy

If you're really interested in diving into the Apple Watch's heart rate tracking features, plan to spend a lot of time in the Health app and the Activity app, both on the iPhone. This is where all the health data from the watch eventually goes, and there are just limitations around how much granular data you can view on a tiny little wrist computer.

The easiest way to get there in the Health app is to open the app and go to the Health Data tab, next to the Today tab, on the bottom of the app screen. Then go to Heart (third menu option) and you can see your heart rate data by category and also by hour, day, week, month, and year.

On the Watch itself you can see what your heart rate was during an exercise session that occurred that day. But reviewing your heart rate from a historical workout session is a bit more complicated. For that, you'll have to go to the Activity app on your iPhone; select the day; scroll down to Workouts, tap on that; and there you'll see a graph of your heart rate during that particular activity.

Doctor's Orders

The Apple Watch (and really, any smartwatch or wrist wearable that's sold directly to consumers) comes with so many health-tracking caveats that there are too many to list here.

The most important thing to remember is that the Apple Watch can't diagnose you with anything; it's supposed to point you toward meaningful data and maybe encourage you to act if there are signs something may be wrong. The Watch alone can't tell you if you have Afib. In fact, as you take an ECG reading, the app displays a warning the whole time "Note: Apple Watch never checks for heart attacks."

Sure, there have been scattered stories about Apple Watch notifications alerting people to an abnormally high heart rate and saving lives. But you shouldn't rely on just the Apple Watch or any smartwatch if you're seriously concerned about your heart health.

WIRED's own Robbie Gonzalez has written a great explanation of the level of preclinical research that went into the Apple Watch's ECG app and irregular heartbeat detection features. Again, these are really more about recording data that can be shared with a physician then they are about alerting you on the spot.

The other caveat involves accuracy. When it comes to tracking heart rate during vigorous exercise, wrist wearables aren't always dead-on. A 2016 study conducted by the Cleveland Clinic using four popular wrist-wearables showed variable results. (Fitbit was even sued at one point for what the plaintiffs said were inaccurate heart rate readings during exercise; Fitbit has since improved its heart rate tracking.) In a 2017 study conducted by Stanford University researchers, the Apple Watch achieved the lowest overall error rate in heart rate monitoring, compared to six other wearables. However, none of them measured energy expenditure very well, the researchers found.

With all that said, the Apple Watch is still pushing the boundaries on what your basic wrist-worn wearable can do. And it's these kinds of health-tracking features that might make someone who once scoffed at the idea of a smartwatch actually consider one now.

Smartwatches offer a lot in today’s society, from taking calls to checking the weather without using a phone. They also contain biosensors, sensors that collect data on the body of the user for the user to use. One of the selling points of the Apple Watch is the ability of electrocardiograms, which could sense the presence of atrial fibrillation and irregular heartbeats. The update 5.1.2 allows older models to detect such signs as well. The smartwatch also records walking and resting heart rates, as well as giving more options during exercise. However, the Apple Watch is not meant to diagnose disorders, rather it is to provide supplementary data and allow the user to look for inconsistencies. The watch even provides a warning, "Note: Apple Watch never checks for heart attacks". Another flaw with wearables is that the data is not always 100% accurate. However, in a study between 4 similar wearable technologies, Apple’s watch had the lowest overall error rate in measuring heart rates.

The development and uses of technology to maintain human health are based, in part, on the changing needs of society.

The Apple Watch is an example of how technology has evolved to let humans have a better grasp on their personal health. With the innovation, there have been stories of the watch saving lives. With heart disease one of the leading causes of death in Canada, it is no wonder that technology has been made to counter it.

Reference

Goode, L. (2018, December 06). Here's How to Take an ECG Reading With Your Apple Watch. Retrieved from https://www.wired.com/story/how-to-take-an-ecg-reading-on-apple-watch/

[czhang11ubio-blog]

Can this breath test tell if you have cancer or one of 16 other diseases?

If you’re a hypochondriac and are looking for a quick and non-invasive way to detect diseases early, doctors in Israel say the technology they’ve developed might be right for you. Their breath test device can diagnose up to 17 diseases, including cancer and Parkinson’s, researchers say.

It’s called the “NaNose” device that can in the figurative sense, “smell” from a breath sample, certain kinds of diseases a patient may have. The device — developed by the Technion-Israel Institute of Technology — works by having a patient breathe into a tube. Sensors inside then analyze more than 1,000 different kinds of “smelly compounds” to detect if anything is wrong.

Breathtec Biomedical, Inc., a private Israeli company recently entered into a license agreement with the makers.

“Indeed, what we have found in our most recent research in this regard, that 17 types of disease have 13 common compounds that are found in all different types of disease, but the mixture of the compounds and the composition of these compounds changes from one disease to another disease,” Prof. Hossam Haick said.

“And this is what is really unique and what really we expect to see and utilize in order to make the diagnosis from exhaled breath.”

The NaNose uses an advanced technology called “artificial intelligent nanoarray.” It involves sensors that analyze data obtained from receptors that “smell” a patient’s breath. The team tested breath samples of more than 1,400 patients and was reportedly accurate 86 per cent of the time.

“So our main idea is to try an imitate what’s going on in nature. So like we can take a canine, a dog and train it to sense the smell of drugs, of explosives or a missing person, we are trying to do it artificially. And we can do that by using these nano-materials,” Dr. Yoav Broza, from the Technion-Israel Institute of Technology, said.

Although the device cannot replace traditional diagnostic methods, developers hope the technology can pave an easier way for affordable and earlier detection of diseases such as multiple sclerosis, Parkinson’s and different types of cancers like breast, prostate and gastric.

At the moment, detecting a disease like lung cancer involves imaging technologies such as CT scans, which are ordered when patients are showing or complaining about certain symptoms. Researchers say sometimes a disease is only detected once it is too late. They hope the device will spearhead the vigorous testing process earlier.

Many companies are now trying to commercialize the technology, the researchers said. They say the future of early diagnosis of disease could be simple and hope health-care systems around the world will integrate their technology.

Israeli doctors have developed a cancer detecting “breathalyzer” of sorts, the NaNose, which they say can detect up to 17 diseases. Patients breathe into a tube and then the sensors analyze and detect scented compounds to look for abnormalities. The sensors “smell” the breath sample and has been experimented on over 1 400 subjects, with a 86% accuracy. Though the device cannot replace the traditional methods, such as CT scans, however, the team hopes that the technology will allow for the detection of conditions earlier, as traditional methods sometimes only catch it once it is too late.

The development and uses of technology to maintain human health are based, in part, on the changing needs of society.

Israeli doctors have stepped forward with their new technology. As the article mentioned, it is important to recognize diseases as early as possible, however, some current technologies only catch things once it is not possible to cure. The NaNose hopes to catch abnormal conditions quickly and effectively. It shows how technology evolves as humans discover ways to better take care of their health. 

Reference

Campanella, E. (2017, February 09). Can this breath test tell if you have cancer or one of 16 other diseases? Retrieved from https://globalnews.ca/news/3238263/can-this-breath-test-tell-if-you-have-cancer-or-one-of-16-other-diseases/

[czhang11ubio-blog]

evolution

How Teeth Became Tusks, and Tusks Became Liabilities by Natalie Angier

Becoming Fearless: Study Finds Major Changes to Domesticated Bunny Brains by Christie Wilcox

Why ‘Vampire Deer’ Have Fangs, While Other Hoofed Mammals Have Horns by Nala Rogers

[czhang11ubio-blog]

An Island Nation’s Health Experiment: Vaccines Delivered by Drone

In Vanuatu, 20 percent of children miss their shots because villages are so hard to reach. It has hired an Australian company to fly them in.

“I am so happy the drone brought the stick medicine to Cook’s Bay as I don’t have to walk several hours to Port Narvin for her vaccines,” her mother, Julie Nowai told a Unicef representative. “It is only 15 minutes’ walk from my home.”

Even paradise can be tough on vaccinators. Vanuatu is an archipelago of 83 volcanic islands. Many villages are reachable only by “banana boats,” single-engine skiffs that 12-foot waves sometimes roll over or smash into cliffs. Other villages are at the end of mountain footpaths that become bogs when it rains, which it does a lot.

Also, many vaccines need refrigeration, and most villages have no electricity.

For those reasons, about 20 percent of Vanuatu’s 35,000 children under age 5 do not get all their shots, according to the United Nations Children’s Fund.

So the country, with support from Unicef, the Australian government and the Global Fund to Fight AIDS, Tuberculosis and Malaria, began its drone program on Monday. It will initially serve three islands but may be expanded to many more.

In the future, that expansion may run into some unusual turbulence — Vanuatu is one of the few places where “cargo cults” are still active, and the drones match their central religious dogma: that believers will receive valuable goods delivered by airplane.

That will have to be handled carefully, a Unicef representative said.

Unlike military drones — which fly high and sometimes fire missiles — commercial drones must venture in low, dodge trees, land gently and even return with payloads, such as blood samples.

As drones have improved, their potential uses in global health have rapidly increased, and many countries and charitable groups are considering them.

Since 2016, Zipline, a California company, has piloted more than 8,000 flights over Rwanda, delivering blood for transfusions. Its drones are launched by catapult and do not land at their destinations, but fly low overhead and drop their payloads by paper parachute.

Zipline has plans to start delivering vaccines in Rwanda within weeks and in Ghana early in 2019.

Emergency drops of rabies vaccine for children bitten by dogs will be the first priority, said Dr. Seth F. Berkley, chief executive officer of Gavi, the Vaccine Alliance, which joined the package delivery company U.P.S. in supporting the Rwandan effort.

Since last year, Unicef has run a “drone test corridor” in the southern African nation of Malawi to test delivery of humanitarian supplies, including vaccines.

But this is the first commercial contract for routine childhood vaccines. Swoop Aero, an Australian start-up, will be paid only for shipments that arrive safely, Unicef said.

Swoop won the contract after proving its drones could fly 30 miles over islands and land within a six-foot target circle. The drones can hold just over five pounds of vaccine, ice packs and a temperature monitor to prove the vials stayed cold in flight.

As the drone arrived on Monday after a 25-minute flight, Cook’s Bay villagers did a welcoming dance around it waving banana leaves.

Vanuatu is “the perfect environment for this,” said Sheldon Yett, Unicef’s Pacific islands representative.

Its population is small and widely spread out, the government is enthusiastic, and there are “no issues with crowded skies,” as in bigger island countries like Indonesia, he said.

But “we don’t want to over-promise,” he added. “We want to start slowly.”

Miriam Nampil, the 55-year-old nurse who gave the shots, lives in Port Narvin, a coastal town whose clinic has a solar-powered refrigerator.

“This drone will change my life,” she said through a translator. “Normally, I must trek about two hours over the mountain each way, and the vaccine carriers are heavy.”

Round trip by boat is about $70 — too much for the health ministry budget, she said, and only safe on calm days.

With its eight-foot wingspan, the white Swoop drone resembles a robot albatross. But it lacks that bird’s calm, ghostly floating flight pattern.

Instead, it shrieks with the enraged buzz of a disturbed hornets’ nest as it shoots straight up in the air and zooms off at speeds of up to 60 miles an hour.

It can maintain 500 feet of altitude in the hot tropical climate and can handle rain and 30-mile-an-hour gusts, said Eric Peck, a former Australian Air Force pilot who founded Swoop with Josh Tepper, a drone racer and robotics expert.

The drone will soon be doing 80-mile round trips, Mr. Peck said, and because it communicates with the Iridium satellite network, it can be piloted from anywhere in the world and will fly even if local cell networks go down, which happens frequently.

Eventually, he said, Swoop will train local pilots and help the health ministry build its own drones by attaching mail-order engines to carbon-fiber wings that can be produced on a 3-D printer.

To introduce Vanuatu’s drone era, nurses are meeting local villagers, and national aviation officials invite them to watch test flights.

“We need to make sure people aren’t spooked by a buzzing thing in the sky descending on them,” Mr. Yett said. “We want to make sure some kid with a catapult doesn’t shoot it down.”

Swoop’s drones are fairly hardy, Mr. Peck said. In Australia, aggressive wedge-tailed eagles have knocked large mapping drones out of the sky, but Vanuatu has no birds of prey that big.

Another issue that will require gentle handling: Vanuatu still has adherents of the John Frum movement, one of the South Pacific cargo cults whose adherents pray for valuables arriving from the sky.

The cults date back more than 100 years, but reached their zenith during and after World War II.

Islanders whose ancestors had been kidnapped by whites to work on plantations in Australia and Fiji watched “silver birds” flown in by the Japanese and American militaries disgorge vast amounts of “cargo” — food, medicines, tools and weapons — which was sometimes shared with them.

The legend spread that the cargo was gifts from the ancestors, but that it had been intercepted and stolen by the foreigners. After the war ended, the cults built airstrips and model planes to lure the “birds” back.

John Frum, a messianic figure, is sometimes portrayed as a black American sailor or sergeant (“John from America”) whose symbol is a red cross like that on military medical tents and whose return will trigger an apocalypse, deliver vast piles of cargo, and make whites and Melanesians change places in the power hierarchy.

On Vanuatu’s Tanna Island, the Frum movement was so powerful that it spawned a political party. During the 1970s independence movement, it opposed the creation of a national government and espoused a return to traditional Melanesian customs.

The health ministry plans to eventually fly drones on Tanna, which may provoke unpredictable responses.

“We’ll go gingerly, very carefully, introducing people to the technology and looking at their reactions,” Mr. Yett said.

But the right people to do that “are local leaders, not Americans with fancy degrees,” he said. “Our goal isn’t to put our thumb on the scale of local belief systems; it’s to make sure kids are immunized.”

Vanuatu, a country in the South Pacific Ocean made up of 83 islands, is the first nation to be dependent on drones to deliver vaccines making the inhabitants’ lives easier. It no longer takes hours for one to get medicine; having the drones bring the medicine to villagers takes just 15 minutes. Drones are able to get medicine to people in remote locations that used to be only reachable by boats, but he ocean proves treacherous and can make waves over 12 feet tall making the journey dangerous. Another thing that drones bypass are the muddy bogs created after rain, preventing transportation of goods. Some nurses make a 4-hour round trip, coming back with carriers of vaccines. The round trip is $70 each time, too much for the health budget of the nation. Among these and other reasons, 20% of children under the age of 5 do not get completely vaccinated. The drone program began in 3 islands first, with plans to expand in the future. The vaccine for rabies is the top priority. But Vanuatu has an interesting circumstance, there are a few active “cargo cults”, religious believers who await delivered valuables from a more modern society. Unicef, one of the supporting organizations, said regarding the religious beliefs, “will have to be handled carefully”. 

The development and uses of technology to maintain human health are based, in part, on the changing needs of society.

Drones are being used to aid and benefit the lives of people, based on the needs of the people. The technology has helped children get vaccinated, possibly saving lives. 

Reference

Mcneil, D. G. (2018, December 17). An Island Nation's Health Experiment: Vaccines Delivered by Drone. Retrieved from https://www.nytimes.com/2018/12/17/health/vanuatu-vaccines-drones.html

[czhang11ubio-blog]

How Teeth Became Tusks, and Tusks Became Liabilities

The situation with the tuskless elephants shows how species can develop to avoid human pressures. The elephants were targeted for the ivory, so natural selection allowed those without tusks to reproduce more often. This is an example of the bottleneck effect that was discussed in class. Humans, mice, narwhals — most mammals rely on ancient genes to produce teeth and tusks. But the tuskless elephants of Africa show that nature can quickly alter the code.

GORONGOSA NATIONAL PARK, Mozambique — We are flying in a Bat Hawk aircraft — which may be named for a raptor that preys on bats but looks more like a giant, lime-green dragonfly — and my hair, thanks to the open cockpit, has gone full Phyllis Diller.

Scudding above flood plains the color of worn pool table felt and mud flats split like jigsaw puzzles, we dip toward the treetops and see herds of waterbuck scatter with an impatient flash of their bull’s-eye rumps.

We are searching for the elusive tuskless elephants of Gorongosa, elephants that naturally lack the magnificent ivory staffs all too tragically coveted by wealthy collectors worldwide.

Tuskless elephants can be found in small numbers throughout Africa, but Gorongosa is known to harbor a sizable population of them, the legacy of a violent 15-year civil war. Tusked elephants were slaughtered for their ivory at a harrowing rate, and the park’s rare tusk-free residents thus gained a sudden Darwinian advantage.

Today, about a quarter of the park’s 700 or so elephants are tuskless, all of them female, and I am determined to catch a glimpse of at least one. Yet a week of ground searches has proved fruitless, and now we are circling in a plane and still nothing and, holy mother of Horton, how can such massive creatures go missing?

“There!” Alfredo Matavele, the pilot, cries triumphantly, pointing toward a cluster of trees. “And there!” pointing toward a watering hole. And there and there. “Do you see them?” he demands.

Oh yes, I see them. Dozens, scores, cliques and claques of elephants, ears flapping like flags, trunks slowly swinging, and many of their faces decidedly free of ivory eruptions. I have found them at last, my sisters in dental deprivation.

Other people may admire elephants for their brains or their complex social lives; I feel a bond with this mutant crew. After all, I’ve learned that we share a basic developmental anomaly, which may well be traceable to the same underlying glitches in our DNA.

Elephant tusks happen to be overgrown versions of the upper lateral incisors — the teeth right next to the front teeth, before you get to the canines. Simply put, tuskless elephants lack lateral incisors.

I, too, lack lateral incisors; moreover, the trait runs in families. Tuskless elephants often have tuskless kin. Both my daughter and my younger brother are missing their lateral incisors. No wonder we’ve always had trouble ripping the bark off trees.

Scientists do not yet know the precise cause of tusklessness, but they’ve made great progress in deciphering the genetic program behind mammalian tooth development generally. It turns out to be an old and widely shared code.

“Tooth development has been very conserved during evolution,” said Irma Thesleff, a developmental biologist at the University of Helsinki in Finland. She has found that mutations associated with tooth abnormalities in mice also show up in genetic studies of people with missing or malformed teeth.

“Elephants are no more different from humans than mice are,” Dr. Thesleff said, “so it’s quite possible that the same gene or genes are involved” in elephant tusklessness and human toothlessness.

For example, it could be a typographical error in the genetic code for a signaling molecule called wnt10a. “This is one of the most commonly mutated genes in humans with missing teeth,” Dr. Thesleff said.

And oh, we gap-mouths are everywhere. An estimated 8 percent of the population is missing one or more of the 32 teeth found in the standard adult set, and that figure rises to about 30 percent if you include a natural absence of the four extra wisdom teeth that many people get yanked out anyway.

Missing lateral incisors is thought to be the second most common form of so-called tooth agenesis. One archaeological study of a 9,000-year-old farming community in Basta, Jordan, found that 36 percent of the inhabitants lacked lateral incisors. Researchers viewed the elevated rate as evidence of inbreeding.

The normal background rate of the condition is more like 2 percent to 4 percent, which, coincidentally or otherwise, is close to the background rate of tusklessness among African elephants.

Even more common in humans than a lack of lateral incisors, said Ariadne Letra, an associate professor at the University of Texas School of Dentistry at Houston, is the absence of the lower second premolars, the teeth with two cusps located in the bottom jaw just before the four-cusped molars.

(I discovered in the course of reporting this story that my husband was born without his second premolars, so I guess I’m grateful my daughter has any teeth at all.)

Through animal studies, scientists have learned that teeth can grow in macabre isolation from other body systems, as though they yearned for a career as novelty dentures at a Halloween party. Isaac Salazar-Ciudad, a theoretical biologist who studies tooth development at the University of Helsinki, explained that if you remove part of the primordial mouth of a mouse embryo and culture it in a dish, it will develop an array of normal-looking mouse teeth.

Although the basic genetic program is widely shared, tooth building is also flexible, susceptible to evolutionary influences.

Teeth develop through the interaction of two types of embryonic tissue, epithelial and mesenchymal, which early in gestation — by about Day 28 in humans — start folding up into each other origami-style to form a series of large and small buds. Those buds can then be sharpened into canines or incisors for slicing into flesh, or flattened and sculpted into molars with any number of cusps for processing high-fiber plants.

The core of a tooth, the pulp, holds the blood vessels and nerve fibers, while the bulk consists of a bone-like material called dentin. The outer coating of calcium phosphate enamel is the hardest substance in the body, which is why animal teeth account for a disproportionate share of the fossil record.

And when lengthened into structures that breach the boundary of the mouth and grow throughout life, teeth become tusks — for digging, fighting, hauling, piercing, threat display.

The diversity of shapes that teeth can assume, combined with their mineralized hardness, said Dr. Salazar-Ciudad, “could be why they have been repurposed as tusks and used for so many tasks.”

In most cases, tusks are recast canines, curving to the side and upward in wild boars and warthogs, or drooping down in walruses like Yosemite Sam’s mustache. In narwhals, the unicorns of the Arctic, the tusk is built of a single overgrown canine that penetrates through the narwhal’s left upper lip in a permanent open wound, which ends up hosting tiny shrimplike creatures with an appetite for shed whale skin.

The narwhal tusk “is the only straight tusk in nature, and the only spiral tusk, too,” said Martin Thomas Nweeia, a narwhal expert who lectures at the Harvard School of Dental Medicine.

Tusks, as a rule, are multipurpose devices. Boars and warthogs apply theirs offensively and defensively, to battle one another during mating season and to gore predators many times their size.

Walruses use their tusks like grappling hooks, to haul themselves out of the water and onto the ice, and as weapons against polar bears and in sexual contests — but not, as commonly believed, to forage for food or pry open oysters.

The purpose of the narwhal’s tusk remains a subject of contention. Some researchers suggest the whales use it to stun their fish prey. Dr. Nweeia and his co-workers propose that it is a kind of sensory organ, for detecting changes in water salinity and temperature.

Elephants are the true masters of the Swiss Army tusk. They use their mighty incisors to dig for salts and minerals, to break off branches and get at the foliage, to pry into trees and peel off the bark — “They really love to to eat bark,” said Joyce Poole, scientific director of Elephant Voices, a research and advocacy group working at Gorongosa — to scoop an errant calf out of a mudhole or lift a sleeping one to its feet.

They coordinate tusks, trunks and feet to de-thorn acacia trees and soften tough grasses, and they stash leafy branches across their ivory shelves for later consumption.

Just as people are left- or right-handed, so elephants have a favored tusk. “If they’re going to break a branch over a tusk, they use the same tusk repeatedly,” Dr. Poole said. A groove forms in the preferred tusk over time.

But it can take two tusks to tangle. From my perch in the Bat Hawk, I watched a pair of large bull elephants spar by locking together their massive tusks, which can weigh well over 100 pounds each — seven times the weight of an average female tusk.

Yet the biophysical properties that make tusks such splendid tools to own have all too often proved their owners’ undoing. People have long coveted ivory for its beauty, ductility and presumed magical properties.

The first appearance of narwhal tusks in medieval Europe is thought to have given rise to the myth of the unicorn, and to a mad surge in demand for the nine-foot spiraling spears. Elizabeth I is said to have paid 10,000 pounds for a narwhal tusk, then the price of an average castle.

The drive to harvest walrus ivory may well have contributed to the settlement of Greenland in the 10th century, and led to the near extinction of walrus populations around Norway, Iceland and other parts of the North Atlantic.

Elephant ivory, however, is considered the finest in the world, and elephants have long been slaughtered to supply it. Despite international efforts to ban the ivory trade, demand still drives a business worth at least a billion dollars a year.

The persistence of elephant poaching has prompted researchers to wonder whether elephants really needed their tusks, and whether they might not be better off if the tuskless trait were to spread more widely through the African population.

Shane Campbell-Staton, an assistant professor of ecology and evolutionary biology at the University of California, Los Angeles, and his colleagues have begun systematically comparing tusked and tuskless elephants in Gorongosa, seeking not only to identify the genes involved in tusklessness but also to solve perplexing patterns of inheritance.

Why, for example, are nearly all the tuskless elephants of Africa female? Among Asian elephants, a related species, many males are tuskless, and recent studies suggest they fare surprisingly well on the sexual battlefieldwhen pitted against tusked rivals.

Dr. Campbell-Staton is also looking at downstream effects of tusklessness.

“We know tusks play an important role in obtaining food,” he said, “so if individuals don’t have that tool, are they using the environment differently, and could those changes have consequences for other animals dependent on elephants as ecosystem engineers?”

Maybe, but from the look of it, the tuskless elephants of Gorongosa are thriving. “They’re in fantastic condition, this is a very good habitat for them, and there’s no indication they’re suffering nutritionally,” Dr. Poole said.

Lateral incisors: who needs them? Better by far to keep the poachers at bay.

The Gorongosa National Park in Mozambique is known to hold a population of tuskless elephants as a result of a violent 15 year war. The tusked elephants were slaughtered for their ivory, leaving the tuskless elephants with a selective advantage. Approximately 175 elephants in the park are tuskless. The evolution of teeth in mammals is shared among many mammals, so it is speculated that the trait of tusklessness and missing teeth in humans are of the same gene or allele. Animals use their tusks to their full potential, especially elephants. They use them to dig for minerals, break branches, peel the bark off trees, and fight for females.  Tusklessness provokes hard questions about gene inheritance and its effects. How are the individuals adapting to their environment without the use of their lateral incisors and how is it affecting the ecosystem? Researchers are asking if tusks are vital for elephants at all, given the rate of poaching, and whether it would be for the better is they lost tusks completely. The tuskless individuals in Gorongosa are as healthy as those with tusks.

Evolution is the process of biological change over time based on the relationships between species and their environments.

The situation with the tuskless elephants shows how species can develop to avoid human pressures. The elephants were targeted for the ivory, so natural selection allowed those without tusks to reproduce more often. This is an example of the bottleneck effect that was discussed in class.

Reference

Angier, N. (2018, September 11). How Teeth Became Tusks, and Tusks Became Liabilities. Retrieved from https://www.nytimes.com/2018/09/11/science/tusks-teeth-elephants-genes.html?rref=collection/timestopic/Evolution&action=click&contentCollection=science®ion=stream&module=stream_unit&version=latest&contentPlacement=21&pgtype=collection

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Becoming Fearless: Study Finds Major Changes to Domesticated Bunny Brains

The process of domestication fundamentally changes an animal’s looks and behavior. Floppier ears and a loss of fear of humans, for example, are nearly universal in domesticated species. Now, researchers have learned what domestication looks  like in the brain—at least, for rabbits.

It’s not exactly clear when rabbits were converted from one of nature’s most skittish animals into the soft, snuggly buddies so often chosen as class pets. But somehow, selective breeding led to bunnies that have lost most of the anxiety their relatives rely on to survive. And it only makes sense that such a shift would show up in their brains.

The research team based largely in Sweden, Spain and Portugal had looked at the genomes of wild and domesticated rabbits before, and found distinct differences in genes associated with brain and neural development. So they decided to look for what those genetic changes might be actually doing.

“No previous study on animal domestication has explored changes in brain morphology between wild and domestic animals in such depth as we have done in this study,” explained Leif Andersson, a geneticist with Uppsala University in Sweden and coauthor on the new paper published this week in Proceedings of the National Academy of Sciences, in a press release. To get this new data, the team raised eight wild rabbits and eight domesticated rabbits (from three breeds) under similar conditions until they were fully grown. Then, they imaged their brains using an MRI.

The brains of the domesticated rabbits were smaller for their body size, but that wasn’t surprising, as similar brain ‘shrinkage’ has been noted for other domesticated species. What really stood out were the other changes to the brain. “Domestic rabbits have a reduced amygdala and an enlarged medial prefrontal cortex,” explained first author Irene Brusini, a PhD student at KTH Royal Institute of Technology in Sweden. When corrected to brain size, the domesticated rabbits’ amygdala’s were roughly 9-10% smaller, while their medial prefrontal cortices were about 11-12% bigger. These are areas of the brain involved in sensing and processing fear, so the authors believe their change in size likely underlies the domestic bunnies’ characteristic friendliness.

And that wasn’t all—there was also a reduction in white matter—the nerve fibers responsible for connecting regions of the brain into functioning circuits—in the domesticated rabbits. “The reduced amount of white matter suggests that domestic rabbits have a compromised information processing,” said Mats Fredrikson, a professor at Uppsala University and one of the paper’s senior authors. And that, he believes, might explain their slower reaction times and generally calm demeanor.

The research team didn’t really expect the magnitude of the differences in the brains—they thought the changes might be too subtle to be seen. But there was no denying the clear differences between the brains, especially since the analyses were conducted blindly (the scientists analyzing the images did not know which brains were wild and which weren’t).

A previous study on mink also found differences in the sizes of different brain parts between wild and domesticated versions (including a reduction in white matter in domesticated versions), as have similar studies in other species, but they lacked the resolution of MRI. These much more detailed data give scientists new insights into how domestication really happens—and it’ll be especially interesting to compare these results with future detailed studies of other domesticated animals to see if all domesticated brains share similar features, or if the process varies dramatically by species.

Rabbits are a breed of domesticated pets, much like the common house cat and dogs. Signs of domestication of most animals often appear as floppy ears and a calm nature. European researchers were interested in how the rabbit became a cuddly pet for humans when in nature, they are one of the most jumpy and flighty species. The team had previously found differences in the genes associated with brain and neural development. They studied 8 wild and 8 domesticated rabbits from 3 different species by raising them in similar conditions, and then they imaged their brains with a MRI scan. The domesticated rabbits were found to have smaller brains, a common trait among domesticated animals. However, what was interesting to the researchers was the smaller amygdala and the enlarged medial prefrontal cortex, both areas that process fear. Researchers believe the size change results in the friendliness of domesticated rabbits. They also found a reduction in white matter, which jeopardizes the processing capabilities. 

Evolution is the process of biological change over time based on the relationships between species and their environments.

This article shows how humans have forced evolution and adaptations onto a species. They have adapted to be less cautious of humans. Humans have selectively bred rabbits with desirable qualities. The organisms with preferred traits were allowed to reproduce and pass on the genes. Humans have altered the environment and allowed certain mutations to move forward. 

Reference

Wilcox, C. (2018, June 27). Becoming Fearless: Study Finds Major Changes to Domesticated Bunny Brains. Retrieved January 6, 2019, from http://blogs.discovermagazine.com/science-sushi/2018/06/27/domestication-changes-bunny-brains/

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Why ‘Vampire Deer’ Have Fangs, While Other Hoofed Mammals Have Horns

(Inside Science) — When do you need a broadsword, and when would you be better off with a dagger? That’s the question that faced artiodactyls, the group of mammals that includes deer, antelope, goats, giraffes, pigs, buffalo and cows, during their evolution.

Many male artiodactyls fight over females using weaponized body parts such as horns and antlers. But pigs and several groups of deerlike animals have tusks instead, and a few species have both. Water deer have tusks so pronounced they are nicknamed “vampire deer.” To understand this variation, researchers compared the habitats and behavior of 63 species, including members of every living artiodactyl group except hippos and whales. They also measured the canine teeth of each species using skeletal specimens in museums.

The species in which males’ canines were enlarged into tusks were much more likely to be small-bodied and to live solitary lifestyles. And while no direct statistical relationship was found between tusks and habitat, the small, solitary species were more likely to live in dense foliage. For example, the rabbit-sized Java mouse deer has tusks more than half an inch long, and it lives in undergrowth so dense that it makes tunnels as it moves from place to place.

This makes sense, say the researchers, because daggerlike tusks are likely to be the most effective weapons in thick underbrush. In open habitats, there is more room to swing more elaborate horns and antlers without getting tangled. Moreover, the mere sight of these weapons is often enough to intimidate another male into backing down.

Such signals would be less useful in dense brush. “There’s no point in signaling, ‘Hey, I’m big and strong,’ because you’re already up close with this opponent. So, it makes more sense to prepare for a direct fight and have a slicing, stabbing-type weapon that can inflict more damage,” said Ted Stankowich, an evolutionary biologist at California State University, Long Beach, who conducted the study with then undergraduate student Doreen Cabrera. They published the findings Nov. 9 in the Journal of Mammalian Evolution.

In this article, Nala Rogers discusses the anatomy of artiodactyls, a groups of animals that have an even number of toes on their hooves. Many males of the order Artiodactyla have specific anatomical characteristics that allow them to fight each other for females. Some species have antlers or horns, while others have tusks, and some species even have both, such as the water deer. They are nicknamed “vampire deer” for their large canine-like tusks. To study why the variation exists, a team of researchers studied the behavioural and habitional differences between 63 species of artiodactyls. They discovered that the species with tusks were more likely to be small, and live alone in vegetation. The horned or antlered animals were often in open areas that allow them to swing their appendages and fight without fear of being caught in branches or bushes. Antlers also serve as a warning to other animals in the area, and would be easily visible in an open area. However, in a forest, the antlers would be difficult to see among similarly shaped things and would serve no purpose. In that case, a pair of tusks would be more suited. 

Evolution is the process of biological change over time based on the relationships between species and their environments.

This article shows the animals that have adapted to suit their needs in the environment that they inhabit. Despite belonging to the same order, the Artiodactyls have all developed in different ways, allowing them to survive the challenges in the environment. 

Reference

Why 'Vampire Deer' Have Fangs, While Other Hoofed Mammals Have Horns. (2018, November 15). Retrieved January 6, 2019, from http://blogs.discovermagazine.com/d-brief/2018/11/15/isns-why-vampire-deer-have-fangs-teeth-while-other-hoofed-mammals-have-horns/

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diversity

Trump Administration Policies Could Threaten Cuban Biosecurity by Brent Crane

Controversial Pesticides Can Decimate Honey Bees, Large Study Finds by Erik Stokstad

World’s Simplest Animal Reveals Hidden Diversity by Charlie Wood