Anthropology.net

Ardipithecus ramidus

I want to be the first to break news to you that Science has published White’s contentious 4.4-million-year-old Ardipithecus ramidus! I caught news of the release on the internet. The link is not live yet, but when it is I’ll fill you in.

Owen Lovejoy is one of the authors of the paper, and he says that the fossil changes the notion that humans and chimps, our closest genetic cousins, both trace their lineage to a creature that was more like today’s chimp and we’ll have to be rewriting our text books soon. This is big folks. What this means is that our common ancestor was a bipedal forest forager and that chimps were an evolutionary offshoot.

White, the lead author, describes the fossil with flexible hands and a brain about a quarter the size of a human’s,

“We can’t say this species was a direct ancestor of modern humans, so we have to be careful. But it suggests that the direction of early hominids was away from the chimp.”

There are a lot of other implications that I won’t get into just yet, but keep checking us out from time to time as we get more!

Here are some of the press releases/news coverage that have come out since I’ve published this post:

• Kent State University Professor C. Owen Lovejoy helps unveil oldest hominid skeleton
• Fossil finds extend human story
• Before ‘Lucy,’ there was ‘Ardi’: First major analysis of early hominid published in Science
• Oldest hominid skeleton provides new evidence for human evolution
• Humanity Has a New 4.4 Million-Year-Old Baby Mama
• Ancient Skeleton May Rewrite Earliest Chapter of Human Evolution
• Fossil Skeleton From Africa Predates Lucy
• Ethiopian desert yields oldest hominid skeleton
• Ardi displaces Lucy as oldest hominid skeleton
• Fossil Primate Ardipithecus Ramidus Described (Finally)
• Oldest “Human” Skeleton Found–Disproves “Missing Link”
• ‘Ardi,’ Oldest Human Ancestor, Unveiled

The latest issue of the Proceedings from the National Academy of Science journal hosts a Out of Africa: Modern Human Origins special feature for free online. I recommend you check it out.

September 22nd, 2009 Cover of the PNAS Out of Africa: Modern Human Origins Special

• Editorial by Richard G. Klein, “Darwin and the recent African origin of modern humans.”
• Perspective by Ian Tattersall, “Human origins: Out of Africa.”
• Perspective by Timothy D. Weaver, “The meaning of Neandertal skeletal morphology.”
• Research Article by J. J. Hublin, “The origin of Neandertals.”
• Research Article by Michael P. Richards and Erik Trinkaus, “Isotopic evidence for the diets of European Neanderthals and early modern humans.”
• Research Article by John F. Hoffecker, “The spread of modern humans in Europe.”
• Research Article by G. Philip Rightmire, “Middle and later Pleistocene hominins in Africa and Southwest Asia.”
• Research Article by Francesco d’Errico, et al., “Additional evidence on the use of personal ornaments in the Middle Paleolithic of North Africa.”
• Research Article by Michael DeGiorgio, et al.,”Explaining worldwide patterns of human genetic variation using a coalescent-based serial founder model of migration outward from Africa.”

Unfortunately, I have not yet had the time to read any of these papers but they I reckon they should be somewhat enlightening.

Speaking of the Johansons and fossils …

Earlier this year, I’ve blogged about the 2009 Human Evolution Leakey Symposium at Stony Brook that I went to. For more about that blog post, click here.

The symposium, entitled “Hobbit in the Haystack: Homo floresiensis and Human Evolution” can now be streamed live through the Stony Brook website. The website also includes previous Human Evolution Leakey symposia. Click here to watch.

Thanks to Afarensis: Anthropology, Evolution and Science for the heads up!

Originally posted on The Prancing Papio

Scientific American recently published a spineless attack on the state of access to paleoanthropological specimens. They titled it, “Fossils for All: Science Suffers by Hoarding,” and John Hawks lend it credibility with a nod in his post. Aside from being spineless, it reeks of ignorance and is tactless. In this post I’ll be discussing why this is not a honest criticism but rather a sloppy slam.

If you read the piece, you’ll notice that Tim White is in the cross hairs of the editors of Scientific American. Why? Tim White discovered Ardi­pithecus ramidus fifteen years ago and continues preparing the specimens. For the editors, that’s enough to pull the guns out and start shooting — claiming he’s sitting on his golden egg far too long and damaging the field as a whole. The cowards at Scientifc American decided to make this bold claim behind a wall of anonymity… publishing this piece simply as the editors. And here in lies the drama and the conflicts of interest.

See, most anthropological editorials on Scientific American are authored by Kate Wong, a twelve year veteran editor for magazine. She is their anthropology editor. Her authority on the subject matter come from a Bachelor’s degree in physical anthropology and zoology from the University of Michigan. University of Michigan is home to Milford Wolpoff, the man who supports multiregional evolution hypothesis… You know the one that claims the origins of Homo sapiens happened in multiple places around the world and not from a common African origin. He’s known for not being a field scientist. Furthermore, within the discipline, the rift between Wolpoff and White is pretty well known and deep. White got his PhD from the University of Michigan. And Wolpoff holds a ~50 year grudge against White in regards to his stance against his single species origin of humans.

Wong has worked closely with another large anti-Tim White camp, the Hadar folks, during the lead up to the Selam news frenzy that we talked about several years ago. The Hadar camp is more or less a Donald Johanson territory as he was there when Lucy was discovered and published the findings. Where Wong may not have an immediate connection to Wolpoff, aside from earning her Bachelor’s from the department Wolpoff teaches in, she does have a clear one with Johanson. She was a coauthor with Donald Johanson on a book published this year, Lucy’s Legacy.

As you may know, there’s also sour grapes shared shared between Johanson and White. I won’t get into those details… But its clearly out there and is exemplified by a passage in Lucy’s Legacy,

“Tim is a very exacting scientist who is not about to be pressured into saying more about ramidus until he is good and ready. But his unwillingness to share more information about the fossils – not to mention access to the remains themselves – in a much more timely way has drawn criticism. (So secretive are he and his team about the fossil that it has been referred to as the Manhattan Project of paleoanthropology.) In fact, spurred in part by Tim’s actions, some researchers have even proposed that funding agencies such as the National Science Foundation establish a limitation on how long the discoverer of a fossil has exclusive access to that material before having to share it with other investigators.” p. 155-156 Lucy’s Legacy

There’s no way to know if Johanson or Wong wrote this particular passage but they both share authorship and royalities of the book and ultimately agree on the points raised in the text.

This is a clear conflict of interest for Scientific American and their anthropological editor, Kate Wong. As an editor of Scientific American, for Wong to be an author of a book which conveys the same criticisms as published under anonymity in their magazine and on their website, shows that she exploited her professional capacity for personal benefit.

In addition to egregious political move by Scientific American, the piece is ignorant of the whole process involved in finding, cleaning, documenting a fossil. Fossils don’t come out of the ground perfect. Believe me, I know. Some of the time these findings are as delicate as a ball of dust and require a great deal of care to preserve them during which time it is the primary investigator/discoverer’s responsibility and privilege.  I’ve actually discussed this before, very thoroughly in this comment thread.

For the editors and other supporters to suggest there should be a limit to how long it takes to prepare a fossil show how they really have no idea to what it takes to curate a fossil. There’s no way to put a time limit on this process. Aside from a select few, most field scientists are professors at universities. Again, as I’ve said before, their time in the field is limited, several months a year, of which time is split between finding new fossils and curating old ones. Field scientists, like White, can’t leave their teaching positions at places like UC Berkeley and dedicate years to preparing the specimen. They do as much as they can and they do it with quality. The Middle Awash, White’s stomping ground, has an impressive record of impactful, frequent fossil discoveries and publications which can’t really be said for Wolpoff and Johanson.

You may consider this a defense of White. I admit this is. This was a shameless jab at White and a despicable, cowardly, and haphazard move by Scientific American. Science is not about quantity. I shouldn’t have to tell freaking Scientific American that. Science is about quality. Editorials like this don’t advance the field. They completely ignore that science is a process and not a product. In doing so they damage the discipline.

One last thing… To the editors of Scientific American, grow some balls next time you wanna put out crap like this and publish your full names along side your criticism. Stand behind your words.

New analysis by a team led by Australian National University doctoral student Debbie Argue showed that Homo floresiensis, nicknamed hobbits, were early hominin and walked out of Africa to Flores. Their findings supports the argument that Homo floresiensis had a unique wrist anatomy that originated from a lineage that lived long before the common ancestor of Homo sapiens and Neanderthals.

With Mike Moorwood from University of Wollongong and Thomas Sutikna from Indonesian Center for Archaeology, Debbie Argue compared 60 skulls and skeletal features from two individual hobbits to those of hominins, chimpanzees and gorillas using cladistic analysis. The result shows that Homo floresiensis “probably took one of two evolutionary paths from Africa to Flores. One began 1.66 million years ago, the other 1.9 million years ago”.

Read more here: Hobbits Walked Out of Africa

Originally posted on The Prancing Papio.

You may have gotten a heads up from John Hawks that a new documentary on Homo floresiensis is around the bend. It is actually going to air tomorrow and you should catch it. It is titled “Alien From Earth,” premiering tomorrow Tuesday, November 11 at 8pm. I’ll definately be watching.

You’ll be seeing clips from Mike Morwood, Dean Falk, Matt Tocheri, Bill Jungers, and David Lordkipanidze explaining several lines of inquiry in regards to whether or not H. floresiensis unusual features are the result of disease, or the result from the “island effect” that often causes large creatures to evolve to be small, or a previously unrecognized branch of the human family tree.

Homo floresiensis foot compared to a modern human's

Dean Falk will be providing an explanation of her 2007 CAT scan of the H. floresiensis brain and the comparisons she did to microcephalic brains. If you don’t remember, she believes the hobbit represents a healthy, and so far unique, specimen of ancient humanity. But as you may also know, the hobbit’s brain size is really small — around 380 cc and the archaeological assemblage attributed to H. floresiensis is way more advanced than what we’ve seen made by other hominids with similar brain sizes.

Matt Tocheri will be providing an explanation of his 2007 analysis of the wrist bones of the hobbit and comparison to African apes. Tocheri argues that based upon wrist bones, Homo floresiensis is for sure a separate species because the bones are indistinguishable from ancestral African apes or other early hominin-like wrists and resemble nothing like modern humans and Neandertals. Bill Jungers will be arguing that he see similarities of the hobbit’s bones to that of Australopithecus afarensis.

Homo floresiensis mandibles

And since the estimated brain to body mass ratio of H. floresiensis lies between that of Homo erectus and the great apes, David Lordkipanidze discusses the possibility that H. floresiensis could be an unsuspected of our evolutionary tree.

All in all this seems like it should be an excellent synopsis on the latest research. I believe I’ve covered most of it before but video is pretty much more entertaining than reading a blog. Anyways, you can see a teaser clip and find more information about the show on the dedicated NOVA web page. And for those that can’t see the show, an online version will appear sometime afterward. Also of related interest is another documentary on H. floresiensis, which Afarensis live-blogged about several days ago. It is titled “The Hobbit Enigma,” and is also viewable online. I’m gonna try and watch that as well. Afarensis clarfied in the comment belowe that “The Hobbit Engima” and “Alien From Earth” are the same documentary — so why not watch it in advance?

Today’s issue of Nature has a brief essay on the role of language in cultural evolution. The authors touch up on a lot basics, such as anatomical localization of brain activity related to language and tool making, FOXP2, and how language has helped humans pass on cultural information more effectively than any other form of communication. Overall, it is a well written review that I want to pass on.

Related, Erin from the Spitton, shared news of the identification of a new language related SNP on the gene CNTNAP2. The paper which reports this is titled, “A Functional Genetic Link between Distinct Developmental Language Disorders,” and was published in the New England Journal of Medicine. I believe it is open access, I got to the full text with no problem. The authors hypothesized that neural pathways downstream of FOXP2 can also affect language impairment.

To identify possible downstream candidates that might be involved in typical SLI, the authors transfected a human brain cancer cell line (SH-SY5Y) to continually express FOXP2. FOXP2 is a transcription factor, meaning it is a controller of the expression of other genes. If it is mutated, it can’t regulate its targets properly and leads to different, sometimes mutant, phenotype. The used a type of test called the chromatin immunoprecipitation (ChIP) assay which identifies how and often where proteins, like the FOXP2 transcription factor, bind to specific regions of the genome. This is done by using specific antibodies that recognize a specific protein or a specific modification of a protein, in this situation anti-FOXP2 antibodies.

The ChIP assay showed that the FOXP2 transcription factor binds to a particular, novel region of interest, the first intron of gene CNTNAP2. When transcribed and translated, CNTNAP2 normally encodes for the protein CASPR2 — a protein that is localized and understood to function in the nodes of Ranvier on myelinated neurons. Of further interest, CNTNAP2 is expressed in the human cerebral cortex, specifically the orbital gyrus and superior frontal anlage, spanning the inferior and middle frontal gyri — all regions know to related to language cognition.

To make sure that FOXP2 was for sure targeting this region, and wasn’t mislead due to any conformational changes that came from the antibody it was complexed with, the authors did some PCR and sequencing and saw that this region of interest, intron 1, does have matching known consensus, binding sequence for FOXP2. They did some other tests that shows that this sequence is highly specific to FOXP2… all of which suggests that this site on CNTNAP2 is definitively a binding site for FOXP2 (CAAATT).

The authors next varied the amount of FOXP2 expression and tried to see if it affects the ultimate expression of CNTNAP2. They were able to show there is a correlation — CNTNAP2 transcript levels were lowest where there are higher levels of FOXP2, suggesting that FOXP2 down regulates CNTNAP2. We haven’t know about FOXP2-CNTNAP2 interactions before, because FOXP2-bound fragment of CNTNAP2 is outside of the classically defined regulatory regions that promoter based microarrays identify… So identifying this pathway is very commendable.

With this downstream candidate gene isolated the authors moved to see how polymorphisms in CNTNAP2 manifest language phenotypes. Their population sample was made up from children from 184 different families where at least one child had a specific language impairment (SLI). The children had wildtype FOXP2, but children who carried the guanine nucleotide at rs17236239 SNP on CNTNAP2 had worse scores on a test that measures their ability to reproduce nonsense words like “brufid” and “contramponist.”

Now don’t get me wrong, this SNP, rs17236239, ain’t on intron 1 — where FOXP2 binds. FOXP2 was used as bait to fish out what gene bites to it. When CNTNAP2 was figured out to be a new novel target of FOXP2, the authors tried to see if CNTNAP2 variations also affect language. And they do. What’s also of interest is that other SNPs in the same regaion that rs17236239 is found also have CNTNAP2 as been linked to delayed speech in children with autism.

I’m really impressed with this paper. It’s a gem. Well written and straight forward. I don’t regularly read papers of such caliber, to be honest… So I really appreciate when I do. The new language related gene is also very important as we begin to piece together the complex network of genes and proteins, anatomy and behaviors that have allowed us to have language and use it.

Eörs Szathmáry, Szabolcs Számadó (2008). Being Human: Language: a social history of words Nature, 456 (7218), 40-41 DOI: 10.1038/456040a

S. C. Vernes, D. F. Newbury, B. S. Abrahams, L. Winchester, J. Nicod, M. Groszer, M. Alarcon, P. L. Oliver, K. E. Davies, D. H. Geschwind, A. P. Monaco, S. E. Fisher (2008). A Functional Genetic Link between Distinct Developmental Language Disorders New England Journal of Medicine DOI: 10.1056/NEJMoa0802828

It has been a while since I blogged anything on paleoanthropology. But once I saw John Hawks‘ post where he pointed out Elizabeth Culotta’s news piece in the latest Science on a new hominin femur from Galili, Ethiopia, I was excited. The femur was presented by Bence Viola to the Society of Vertebrate Paleontology, which meet for their annual get together about two weeks ago.

Galili, Ethiopia

Very recent argon-argon dating was done on, and Viola shared those to the Society. The bone is somewhere between between 4.38 million and 3.92 million years old. The bone indicates the individual was larger than lucy but isn’t complete. From what Culotta says, it seems as the distal end is broken off.

The anatomy of the head and neck of the femur suggest the owner was bipedal. But, the distribution of cortical bone around the femur is even. Arboreal primates have an even distirbution of cortical bone around the neck of the femora. The force of gravity and the weight of a bipedal individual causes a lot of stress on the lower half of the femoral neck. It has been observed that the cortical bone of femoral necks of bipedal hominids is thicker on the lower half, as a response to this stress. If you know anything about the debate between the Orrorin camp and the Ardipithecus camp, this should be all too familiar of a discussion.

I first read about hominid remains from Galili in this 2004 piece, which reported on the discovery of an almost complete lower right third molar (GLL 33) likely that of a male Australopithecus afarensis. Hawks pointed out a recent paper which describes the paleoecology of Galili — a open woodland to bushland ecosystem at a time when A. afarensis began replacing A. anamensis. So it is certainly possible that a semi-arboreal/bipedal hominids were navigating this terrain… But, Yohannes Haile-Selassie, who is also working on a 4 million years old hominid from Ethiopia, isn’t too convinced.

What do you think?

E. Culotta (2008). SOCIETY OF VERTEBRATE PALEONTOLOGY 68TH ANNUAL MEETING: Two Legs Good Science, 322 (5902), 670-671 DOI: 10.1126/science.322.5902.670b

As you may have noticed, I’ve taken a bit of a blogging hiatus. I have actually taken the time off to write some software in Python that I hope to release soon… a project that you may have seen in previous iterations.

Speaking of some software, I have do have some less cryptic news to share with you. I have been a part of the development team behind FOROST, a forensic osteology metabase, that physical anthropologists and forensic specialists may find useful since it provides images and descriptions of special pathological and taphonomic cases. We’re ready to showcase the site and encourage you to use it and pass it onto others!

This metabase primarily functions to expand one’s access to comparative samples. By providing a portal to well documented images and attribution, we foresee that FORST will help connect investigators to collections that they may have never knew about. We’ve decided to call it a metabase because we’ve decided not to house the images and metadata linked to each specimen. Rather, we curate a subset of the information, which is determined by contributors, and is in turn searchable from the FOROST query builder. Each item in the database is ultimately stored on the participant members’ servers and is branded to their liking. I am hopeful that this unification of forensic data will pool together distributed specimen information while retaining individual attribution. I’m even more hopeful that it will facilitate collaboration and standardization of forensic criteria. It is like one big digital potluck party…

The metabase is queriable now. You can poke around and see how we’ve gone about showing the results from the preliminary institutions that have participated. You’ll find some pretty cool images of blunt force trauma and gunshot wounds. I’ve worked with a close colleague of mine, Dr. Henry Gilbert, who approached me with the idea a while back ago. My role has been primarily a consultant, where I’ve helped with brainstorming the database design, setting up the development environment and PHP coding practices. The senior developer is Raul Castillo. I recently started making a translation of the site into Farsi, as well. I have also had the pleasure to work with researchers and developers from UNAM.

I really am excited about this project and I’d really like to hear your feedback. We’re far from calling it a completed project and understand it may have some quirks here and there. I want to know about your experiences using the metabase. You can shout out your ideas and suggestions for improvements here in the comments thread, or you can send the project manager, Socorro Baez, an email, if you prefer the private route. You should also contact her if you want to participate too.

Oh yeah! FOROST will also be announced at a conference at the Instituto de Investigaciones Antropológicas, at UNAM on the 16th to the 20th of March, 2009. I plan on attending the conference, which will host talks by Carlos Serrano Sánchez and Douglas Ubelaker, as well as others. If you’re interested in how forensic science intersects with anthropology, I recommend you attend. Let me know if you do decide to go, maybe we can have a meetup of Anthropology.netters.

Bergmann’s rule is an observation that body mass of endotherms increases with altitude and colder climate. Neandertals fit this rule, their barrel chests and wide hips, indicate they had large bodies, and thus smaller surface area relative to their body mass. This feature made them comparatively inefficient at radiating their body heat off into the surrounding environment than smaller bodied hominins…. which is an advantageous trait to have in cold environments.

Another similar theorem, Allen’s rule, summarizes the observation that endotherms from colder climates usually have shorter limbs compared to counterparts from warmer climates. Similar to Bergmann’s rule, shorter limbs keep blood and heat closer to the core of the body, reducing heat loss.

All this may sound like adaptionist mumbo-jumbo, but researchers have observed these adaptations to cold climate in other animals. Compare the profiles of polar bears, walruses, and mammoths to cheetahs, antelopes, and giraffes, and you’ll see how some of this makes sense.

Homo neanderthalensis from la Chapelle aux saints

Anyways, I digress. There are two different camps currently hashing out whether the Neandertal facial morphology is due to random genetic drift or a mix of archaic traits and climate influenced adaptations. One of the more hotly debated facial traits, the Neandertal nose, doesn’t quite fit what we expect to see in cold climate adapted species. The Neandertal nose is broad and wide, a feature seen in tropical climates. Physiologists have shown that narrow noses better warm the air being inhaled and prevent evaporation of water in such dry environments by recapturing moisture during exhalation. Wide noses dissipate heat very efficiently.

Some researchers, like Milford Wolpoff, have suggested that there’s a growth and development reason to why we don’t see narrow Neandertal noses. For example, the effects of large teeth and broad palates could have affected the reduction of the nasal aperture, and were most likely inherited traits from Pleistocene ancestors. In a new Journal of Human Evolution paper that Dienekes pointed out this week, researchers from the University of Iowa have investigated the relationships between nasal breadth, intercanine breadth, and facial prognathism. The paper is titled, “The paradox of a wide nasal aperture in cold-adapted Neandertals: a causal assessment.” They tested variants of the following hypothesis: Does the distance between the two upper canines correlated with nasal breadth in modern and archaic Homo?

Intercanine Breadth Measurement

Their sample set of modern humans included 119 crania of Bantu people and 112 crania of Western Europeans. The sample of human ancestors included 11 from the early Upper Paleolithic, 9 from the late Upper Paleolithic all coming from Eurasia. They also included 15 samples from the late Stone Age in Africa, and 14 Pleistocene Homo. Like I mentioned earlier, they measured the distance between the two canines, known as the ICB. In anatomical terms that’s the distance between the lingual tubercles of the maxillary canines, or the pointy parts of your vampire teeth. The lower facial prognathism (BPL) is a measurement of basion to prosthion. Upper facial prognathism (BNL) is a measurement of basion to nasion. Of course some fossils didn’t have all the measurements so predictions were made by least squares regression.

The authors conclude that intercanine breadth cannot fully explain nasal breadth from their sample set, which goes against what anatomist Gustav Schwalbe said in the later 1800′s and what E.V. Glanville reconfirmed in the late ’60s. They also note that the development of the anterior palatine bone does not affect the growth trajectory of the breadth of the nose. While, they do suggest that nasal breadth is affected by the ICB, the lower facial prognathism impacts nasal breadth more than any other trait.

They finally suggest that the plesiomorphic retention of a prognathic lower face is due to the extended time the premaxillary sutures remain open during development. This is lower face prognathism is not a derived trait, but rather a retention of archaic traits, seen in early humans. But that’s not to say the Neadertal nose never adapted to cold climates while the rest of their body did. Neandertals from colder climate have been characterized with a more narrow superior nasal dimensions, which have ultimately been linked to aspects of airflow dynamics.

N HOLTON, R FRANCISCUS (2008). The paradox of a wide nasal aperture in cold-adapted Neandertals: a causal assessment Journal of Human Evolution DOI: 10.1016/j.jhevol.2008.07.001