#so no direct relation to lucy (australopithecus)

[gemwolfz]

pop culture brings us together. shoutout someone in anthropology who learned the word simian and was like oh... that's why miss simian from the amazing world of gumball is named that... which amused and delighted the professor

[sciencespies]

These are the Decade’s Biggest Discoveries in Human Evolution

https://sciencespies.com/nature/these-are-the-decades-biggest-discoveries-in-human-evolution/

These are the Decade’s Biggest Discoveries in Human Evolution

Smithsonian Voices National Museum of Natural History

These are the Decade’s Biggest Discoveries in Human Evolution

April 28th, 2020, 12:26PM / BY

Briana Pobiner

&

Rick Potts

Some of the most exciting discoveries in human evolution happened in the last decade. (Human Origins Program, Smithsonian Institution)

Human evolution is one of the most vibrant areas of scientific investigation. In the past decade we’ve seen many discoveries that add to our understanding of our origins. To mark the 10th anniversary of the Smithsonian’s “David H. Koch Hall of Human Origins,” here are some of the biggest discoveries in human evolution from the last 10 years.

We have ancient DNA

Scientists extracted ancient DNA from this 76,000-52,000-year-old fossil pinky bone in 2010, leading to the identification of the Denisovan population. (Max Planck Institute for Evolutionary Anthropology)

DNA tells us a lot about who we are now. But we also look to ancient DNA to learn about our origins.

When the decade first started, scientists recovered ancient genetic material from a fossilized finger bone found in the Denisova Cave in Siberia. They tested that material and discovered that the DNA didn’t match that of modern humans or Neanderthals. Instead, it belonged to a previously undiscovered species of early humans now called Denisovans. It was the first time a new species has been identified using ancient DNA.

What does this tell us? The human genome is a wondrous archive of our relationships with ancient species no longer around.

Meet our new ancestors

737 fossils of Homo naledi, a new early human species announced in 2015. (Image by John Hawks/Courtesy of University of the Witwatersrand)

Over the past decade, we welcomed four new species to our family tree, including the mysterious Homo naledi.

In 2015, scientists announced the discovery of fossils of at least 15 individuals of this species in a deep, dark chamber of the Rising Star Cave system in South Africa. It’s five years later and we still aren’t sure how they got there. There’s no evidence they were dragged there by predators or washed in by water. And no other animal bones were found in the cave except for the bones of a single owl. Were the bodies placed there deliberately? If so, by whom? It’s a mystery still to be solved.

What we do know is that the remains are from 335,000-236,000 years ago and show a unique mix of ancient and human traits, making Homo naledi one of several species that overlapped in time with our own.

Fossil discoveries tell more of our story

This 3.8-million-year-old cranium of Australopithecus anamensis helped scientists see how the face of an early human species looked. (Photograph by Dale Omori, courtesy of the Cleveland Museum of Natural History)

Not all fossil discoveries lead to a new species. But new fossils always reveal more of our story.

In the past ten years, we’ve found fossils that widen both the geographic and time range of several early human species. But one of the most exciting discoveries is of a nearly complete 3.8-million-year-old cranium of Australopithecus anamensis from Woronso-Mille, Ethiopia. Until this find was announced in 2019, researchers had only found bits and pieces of this species from various sites across Ethiopia and Kenya.

Fossils older than 3.5 million years are extremely rare. But what makes this discovery particularly amazing is that it challenges the previous assumption that A. anamensis was the direct ancestor of the species Australopithecus afarensis—to which the famous fossil “Lucy” belongs. Thanks to this skull, we now know that the two species overlapped in time.

We made tools earlier than we thought

A 3.3-million-year-old stone tool in situ at the Lomekwi 3 excavation site in Kenya. (Mission Préhistorique au Kenya/West Turkana Archaeological Project)

When you think of technology today, you might picture computers, smartphones, and gaming consoles. But for our ancestors millions of years ago, it would have been stone tools.

We long thought our ancestors began making these tools about 2.6 million years ago. But a discovery announced in 2015 pushed that date back. The research team found pieces of altered stone in Lomekwi, Kenya, that date to 3.3 million years ago. These stones are larger and simpler than those that were previously thought to be the oldest stone tools.

The new discovery suggests that the ability to flake stone tools arose at least 700,000 years before it became a regular habit in the lives of our ancestors.

We’re older than we thought

Reconstructions of the earliest known Homo sapiens fossils based on CT scans of multiple original fossils. (Philipp Gunz, MPI EVA Leipzig, License: CC-BY-SA 2.0)

Stone tools aren’t the only things that are older than we thought. Humans are too.

Just three years ago, a team of scientists made a discovery that pushed back the origin of our species, Homo sapiens. The team re-excavated a cave in Morocco where a group of miners found skulls in 1961. They collected sediments and more fossils to help them identify and date the remains. Using CT scans, the scientists confirmed that the remains belonged to our species. They also used modern dating techniques on the remains. To their surprise, the remains dated to about 300,000 years ago, which means that our species originated 100,000 years earlier than we thought.

Social Networking Isn’t New

Obsidian from Olorgesailie, Kenya revealed that social networks existed long before we thought. (Human Origins Program, Smithsonian Institution)

With platforms like Facebook, Twitter and Instagram, it hard to imagine social networking being old. But it is. And, now, it’s even older than we thought.

In 2018, scientists discovered that social networks were used to trade obsidian, valuable for its sharp edges, by around 300,000 years ago. After excavating and analyzing stone tools from southern Kenya, the team found that the stones chemically matched to obsidian sources in multiple directions of up to 55 miles away. The findings show how early humans related to and kept track of a larger social world.

We left Africa earlier than we thought

2.1-million-year-old stone tools from the site of Shangchen on the Loess Plateau of central China. (Zhu Zhaoyu, Chinese Academy of Sciences)

We’ve long known that early humans migrated from Africa not once but at least twice. But we didn’t know just how early those migrations happened.

We thought Homo erectus spread beyond Africa as far as eastern Asia by about 1.7 million years ago. But, in 2018, scientists dated new stone tools and fossils from China to about 2.1 million years ago, pushing the Homo erectus migration to Asia back by 400,000 years.

Also in 2018, researchers announced the discovery of an upper jaw in Israel that looked like that of our own species, Homo sapiens. The jaw ended up being 174,000-185,000 years old. This discovery—along with others from China and Greece—suggest that Homo sapiens wandered short-term into Eurasia well before the worldwide migration that began 70,000 years ago.

Briana Pobiner leads the National Museum of Natural History’s Human Origins Program’s education and outreach efforts and manages the Human Origins Program’s public programs. Her research centers on the evolution of human diet (with a focus on meat-eating), but has included topics as diverse as human cannibalism and chimpanzee carnivory. Her favorite field moments include falling asleep in a tent in the Serengeti in Tanzania while listening to the distant whoops of hyenas, watching a pride of lions eat a zebra carcass on the Kenyan equator, and discovering fossil bones that were last touched, butchered and eaten by one of her 1.5-million-year-old ancestors.

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Paleoanthropologist Dr. Rick Potts heads the Human Origins Program at the Smithsonian’s National Museum of Natural History. In partnership with the Kenya Museums, Potts leads ongoing excavations in southern and western Kenya. His research focuses on how environmental instability has affected human evolution and our evolutionary adaptations. He is the curator of the Smithsonian’s “Hall of Human Origins” and the traveling exhibit “Exploring Human Origins.” He also authored the exhibit companion book What Does It Mean To Be Human?

More From This Author »

#Nature

[anth-315-broughman-lucy]

Blog Entry # 4 - Species and Classification

Species Assignment

Lucy otherwise known as (AL-288-1) was classified under the genus Australopithecus afarensis. Donald Johanson states that in Australopithecines the buccal face of P3s usually have vertical wear striae caused by occlusion with the upper canines (Johanson 7). The P3s in Lucy display a sloping buccal surface and the M3s are fully erupted, and show the occlusal wear facets that Johanson had described (Johanson 296). Johanson describes Australopithecines as having smaller mandibles with relatively narrow incisor regions (Johanson 6). Lucy shows a less heavily built mandible, and the incisors were absent, however the region appeared to be rather small. (Johanson 296). In terms of post crania traits the phalanges in Australopithecines tend to be curved longitudinally, Lucy’s phalanges show signs of curvature (Johanson 8). Australopithecines show high levels of dimorphism in body size and this can be seen when comparing Lucy (a rather small Australopithecine) to a more average size male Australopithecine. Johanson states that the pelvic region and lower limbs of Australopithecines indicate adaptations for bipedalism (Johanson 8). Lucy's pelvic region is similar to modern day humans, for example, the sacrum in humans is short and wide and those characteristics are also seen in Lucy’s sacrum.These are some of the few traits that Johanson listed that Lucy expresses that are found in all Australopithecines. It is stated in “Pleistocene hominid discoveries in Hadar, Ethiopia”, that these individual traits and even single specimens in the new collections can be matched in the other samples representing different taxa. However, the overall character complex seen in the Hadar and Laetoli fossils is distinct from others previously found and described (Johanson 8). So it is best to keep in mind that even though there might be some resemblances to other species found in Lucy’s skeleton that there is enough evidence to prove that she was a Australopithecine. 

Species Classification

The genus Australopithecus was first named in the beginning of the twentieth century, the genus included at least seven species from South Africa, Tanzania, Kenya, Ehtiopia, and Chad (Haile-Selassie 3323). Some anthropologists feel the need to separate Australopithecus boisei, Australopithecus aethiopicus and Australopithecus robustus into there own genus, Paranthropus (Haile-Selassie 3323). The separation is based on the different morphological features that they posses. Australopithecus afarensis was at one time recognized as the oldest indisputable evidence of the family Hominidae at 3.6 Ma. However, at the end of the twentieth century and beginning of the twenty first century new hominoid taxa were recovered (Haile-Selassie 3323). During the 1990s Ardipithecus ramidus (4.4 Ma) was discovered in Ethiopia, and was followed by the discovery of Australopithecus anamensis (3.9-4.2 Ma). Recent fieldwork in Ethiopia, Kenya, and Chad have pushed the record further into the Late Miocene with the discovery of Ardipithecus kadabba, Orrorin tugenensis, and Sahelanthropus tchadensis. The phylogenetic relationships among these earlier hominids remain a point of contention and Pliocene hominid fossils are poorly sampled from the 3.6-3.9 and 4.4-5.2 Ma time intervals (Haile-Selassie 3323-3324).

- Early Australopithecus

For the most part information on genus Australopithecus was rather scarce until new discoveries from the Early Pliocene in eastern Africa came about. Au. anamensis is the earliest species of the genus and was documented from remains found in Kenya and Ethiopia, dating between 4.2 and 3.9 Ma. (Haile-Selassie 3324). There was some debate on Au. afarensis, some anthropologists thought that there was too much variation in the species to only represent one single species. The argument was that do to the species hypodigm that was pooled from two asynchronous and geographically disparate areas, Laetoli and Hadar, that it represented more than one species. However, more specimens were found in Hadar and a detailed analyses of the pooled hypodigm showed that the amount of variation in Au. afarensis was not sufficient enough to categorize them into two separate species (Haile-Selassie 3324). The variation that was found was do to the directional trend toward an increase in mandibular size through time, but not in the size of the teeth. The post crania anatomy inferred to indicate obligate bipedality and some argued that it was partially arboreal (Haile-Selassie 3324). These were all some contributing factors that caused for some anthropologist to spilt the species into two. We now know that Au. afarensis was a biped, however the bipedalism it expressed was not similar to modern day humans. 

- Phylogentics 

Australopithecus anamensis is suggested to have rapidly evolved from its ancestor Ar. ramidus, however this is continually tested do to the new discoveries of Ar. radius. Australopithecus anamensis and Au. afarensis are considered by most anthropologist a chronospecies pair, creating a single phyletically evolving lineage. Other analytical methods have not yet disproved the belief of a single evolving lineage (Haile-Selassie 3328). The Woranso-Mille hominids (3.6 - 3.8 Ma) are morphometrically intermediate between Au. afarensis and Au. anamensis. These fossils best represent a sample that connects the temporal and morphological gaps between Au. afarensis and Au. anamensis, which helps support the belief of a chronospecies pair. Every line of evidence suggest that Au. anamenis was earlier than Au. afarensis (Haile-Selassie 3324). The differences attributed at the species level was caused by the lack of sufficient fossils from the time period 3.9-3.6 Ma (Haile-Selassie 3328).

Pictured above: This phylogenetic tree presents Paranthropus as a monophyletic group. Photo from: http://tolweb.org/treehouses/?treehouse_id=4438

- Cladistics 

Cladistics analysis on four site-samples of Au. afarensis and Au. anamensis (Hadar, Laetoli, Allia Bay, and Kanapoi) demonstrated that the Au. anamensis-Au. afarensis linage is paraphyletic because the younger Au. afarensis sample from Hadar appears to be the sister taxon of Au. africanus (Haile-Selassie 3328).  Even though Au. afarensis is a paraphyletic single the Laetoli sample shares some dentognathic features exclusively with Au. anamensis. The Woranson-Mille specimens, regardless of the group they are assigned, further the notion of the paraphyly of not only the entire Au. afarensis-Au. anamensis lineage, but also that of Au. anamensis (Haile-Selassie 3328). “Kimbel et al. (2006, p. 146) suggested that the two most preferred solutions for the taxonomic conundrum related to Au. afarensis and Au. anamensis are the recognition of a single evolutionary species or the maintenance of the status quo... The evidence from Woranso-Mille strongly supports the former as the most parsimonious solution and Au. africans as the sister taxon of this species” (Haile-Selassie 3328). 

Work’s Cited

Haile-Selassie Y. 2010. Phylogeny of early Australopithecus: new fossil evidence from the Woranso-Mille (central Afar, Ethiopia). Philosophical Transactions: Biological Sciences [Internet] 365:3323–3331. Available from: https://www.jstor.org/stable/20778971?Search=yes&resultItemClick=true&searchText=Phylogeny&searchText=of&searchText=early&searchText=Australopithecus:&searchText=new&searchText=fossil&searchText=evidence&searchText=from&searchText=the&searchText=Woranso-Mille&searchText=(central&searchText=Afar,&searchText=Ethiopia)&searchUri=/action/doBasicSearch?Query=Phylogeny of early Australopithecus: new fossil evidence from the Woranso-Mille (central Afar, Ethiopia)&group=none&wc=on&fc=off&acc=on&refreqid=search:b78a10c5922444fe84d58cf25985facc&seq=1#page_scan_tab_contents

Johanson DC, White TIMD, COPPENS YVES. 1978. A New Species of the Genus Australopithecus (Primates: Hominidae) From The Pliocene Of Eastern Africa. Kirtlandia:1–14.

Johanson DC, Maurice Taieb M. 1982. Pleistocene hominid discoveries in Hadar, Ethiopia. Nature. Nature [Internet] 260:293–297. Available from: https://www.researchgate.net/publication/22337974