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Ravens Are Evolving, and Not in the Way You’d Expect

A new study shows that the common raven is anything but commonplace in its evolution.

Using DNA samples taken from ravens for nearly twenty years, the study provides evidence that common ravens on the western coast of North America have split into three genetically distinct groups. What’s more, two of these lineages appear to be in the process of melding back into one, scientists report Thursday in the journal Nature Communications.

For a long time, we’ve tended to think of the evolution of species as a branching tree, with new species splitting off as their own branches, says Anna Kearns, an evolutionary biologist at the Smithsonian Conservation Biology Institute.

“You see a split and then you see another split, and then you see another split, but you rarely see those two branches that are split come back together again,” says Kearns, who led the new study.

But occasionally, the branches of a family tree do merge back together, and two lineages—or groups that were on their way to becoming separate species—become one. Scientists call this “reticulate evolution,” says Kearns, and it’s been seen in only a handful of other species, including finches and two kinds of fish.

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Supercomputer model reveals how sticky tape makes graphene

Scientists at UCL have explained for the first time the mystery of why adhesive tape is so useful for graphene production.

The study, published in Advanced Materials, used supercomputers to model the process through which graphene sheets are exfoliated from graphite, the material in pencils.

Graphene is known for being the strongest material in the world, lightweight and with extraordinary electrical, thermal and optical properties. Unsurprisingly, it offers many benefits for commercial application.

There are various methods for exfoliating graphene, including the famous adhesive tape method developed by Nobel Prize winner Andre Geim. However little has been known until now about how the process of exfoliating graphene using sticky tape works.

Academics at UCL are now able to demonstrate how individual flakes of graphite can be exfoliated to make one atom thick layers. They also reveal that the process of peeling a layer of graphene demands 40% less energy than that of another common method called shearing. This is expected to have far reaching impacts for the commercial production of graphene.

Read more.

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Guardians of the Galaxy Vol. 2 (2017)

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Dramatically large females are the norm in some species of frogs, turtles, lizards, snakes, and spiders. And there’s a reason for their heft—aside from the obvious fact that big is beautiful. 

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A foggy afternoon in Yosemite National Park

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Yellow Journalism - WTF fun facts

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“Thor is a Valkyrie fan, which I think is such a nice thing for this male character to have been a fan of these female warriors.” — Tessa Thompson

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I hope you all had a great valentine’s day!

Here is a story about a romantic little exoplanet…57 lightyears away…

http://news.nationalgeographic.com/news/2013/08/130808-exoplanet-pink-low-mass-star-space-science/

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Logan (2017)

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Stinging Nettle Slug Caterpillar (Cup Moth, Limacodidae) “Medusa” This was a bucket-lister for me! I had seen images of this large staggering species before from elsewhere in SEAsia and it was a matter of whether it occurred locally. It remains unidentified but bears similarities to the only known immature stage of the genus Phocoderma. As usual, in the absence of an ID (and even then for ease of reference), I have issued a nickname - “Medusa” by Sinobug (itchydogimages) on Flickr. Pu’er, Yunnan, China See more Chinese caterpillars on my Flickr site HERE…..

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DNA which only females have          

In many animal species, the chromosomes differ between the sexes. The male has a Y chromosome. In some animals, however, for example birds, it is the other way round. In birds, the females have their own sex chromosome, the W chromosome. For the first, researchers in Uppsala have mapped the genetic structure and evolution of the W chromosome.

In a study published today in Nature Communications, Linnea Smeds, Hans Ellegren and their colleagues show that, surprisingly enough, a bird’s W chromosome does not contain genes that lead to the development of a female.

The W chromosome seems instead to function as some kind of buffer for females since it contains genes similar to those in the X chromosome. In order for certain genes to work, it is critical that an individual has two copies of that gene. In this way, the W chromosome can serve as a complement for females who only have one copy of the X chromosome. 

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Yep, Earth’s magnetic field may switch, it has happened along the geologic history (geomagnetic reversal). We can do little to avoid it (or predict it) but something we will have to do to mitigate eventual consequences (surely not a big deal, see this wiki on effects on biosphere, or this article on Medical Daily, or this short essay on technological hazards).

Captions:

Top animation: This animation shows the movement of the north magnetic pole at 10-year intervals from 1970 to 2020. The red and blue lines indicate “declination,” the difference between magnetic north and true north depending on where one is standing; on the green line, a compass would point to true north.

Bottom animation: In this animation, the blue lines indicate a weaker magnetic field, the red lines a stronger one, and the green line the boundary between them, at 10-year intervals from 1910 to 2020. The field is weakening over South America, and the red area over North America is losing strength.

Via Undark: The Magnetic Field Is Shifting. The Poles May Flip. This Could Get Bad.

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Imagine if birth control was this natural.....

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5 things you didn’t know about... the Golden Gate Bridge

Credit: verygreen/Flickr

1. Despite earlier calls for a bridge to be built to span the Golden Gate strait, it wasn’t until 1919 that city officials enlisted civil engineer Michael O’Shaughnessy to assess the feasibility of such a project. The construction of a bridge here had previously been viewed as impossible due to the necessary span and height needed to allow ships to pass underneath, and the consequent expenditure.

2. Most quotes put the cost of a bridge at more than US$100m, but structural engineer Joseph Baermann Strauss suggested it could be done for US$25–30m.

3. Construction began in 1933 and was completed in 1937.

4. A safety net was implemented during construction to protect the workers from falling. The net saved 19 men, giving way to the formation of a club for those who had cheated death – the Halfway to Hell Club.

5. The bridge was originally designed to withstand lateral forces during earthquakes and strong winds. However, following the Loma Prieta earthquake in 1989, a seismic retrofit programme began.

To find out more see our upcoming issue of Materials World. 

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I’m getting ready to climb this clay-rich slope. What are you up to?

Yes, I took this selfie. Here’s how: https://go.nasa.gov/2DXwofq

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Wave clouds These are a form of orographic cloud, similar to the lenticular version we often share hanging above mountains. This example was captured by the TERRA satellite near Amsterdam Island (see http://tinyurl.com/m4lv82s) deep in the Indian Ocean, halfway between South Africa and Australia. The northernmost volcanic isle isle on the Antarctic plate set up undulating waves of air that produced these repeated zones of condensation as it rose and fell. This phenomenon occurs when moist and dry layers of air alternate, and only the moist ones produce clouds as they rise above their condensation altitude. Loz Image credit: NASA http://www2.gi.alaska.edu/ScienceForum/ASF8/811.html http://earthobservatory.nasa.gov/IOTD/view.php?id=6151&src=fb