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Archive for the ‘Human Evolution’ Category

Neanderthals in your past

May 6, 2010 3 comments

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Tomorrow’s Science will have a series of freely available papers on the Neanderthal genome. One claim is that that between 1% and 4% of the DNA of certain modern groups is attributable to hybridization between Homo sapiens and Neanderthals. Carl Zimmer and John Hawks have more. Jerry Coyne has a handy-dandy guide to the paper here.

The original paper is here and the abstract reads:

Neandertals, the closest evolutionary relatives of present-day humans, lived in large parts of Europe and western Asia before disappearing 30,000 years ago. We present a draft sequence of the Neandertal genome composed of more than 4 billion nucleotides from three individuals. Comparisons of the Neandertal genome to the genomes of five present-day humans from different parts of the world identify a number of genomic regions that may have been affected by positive selection in ancestral modern humans, including genes involved in metabolism and in cognitive and skeletal development. We show that Neandertals shared more genetic variants with present-day humans in Eurasia than with present-day humans in sub-Saharan Africa, suggesting that gene flow from Neandertals into the ancestors of non-Africans occurred before the divergence of Eurasian groups from each other.

(image source)

Orangs, Humans & ERVs

July 6, 2009 6 comments

Last week I briefly posted on the claim being made by John Grehan and Jeffrey Schwartz that morphological evidence indicates that the orang is our closest living relative and that molecular evidence accumulated over the past 40 years that the chimpanzee is closer is flawed and can be discarded. A vigorous discussion ensued and is still ongoing.

Last night I posted a question that remains unanswered by the proponents of the orang claim, so I’m going to repeat it here in a little more detail to see what we can ascertain. As a starter, let’s allow the claim that the molecular methods that support the Homo-Pan clade are flawed and should be discarded. How does a supporter of the Homo-Pongo clade explain the distribution of endogenous retroviruses within the great apes, a distribution that would appear to support the closer affinity of Homo and Pan.

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(Source: Lebedev, Y. B., Belonovitch, O. S., Zybrova, N. V, Khil, P. P., Kurdyukov, S. G., Vinogradova, T. V., Hunsmann, G., and Sverdlov, E. D. 2000 “Differences in HERV-K LTR insertions in orthologous loci of humans and great apes.” Gene 247: 265-277.)

Now it would appear (to me at least) that these results which are not dependent on the methods criticized by Grehan and Schwartz would unambiguously offer support for the Pan-Homo clade (and indeed the molecular phylogenies that they discard).

Thoughts?

Orangs in the family tree

June 29, 2009 61 comments

Many readers may be aware of the recent paper (in Journal of Biogeography no less) by Grehan and Schwartz claiming that there is sufficient morphological evidence to support the claim that orangutans are our closest living relatives, while simultaneously dismissing all of the genetic evidence for chimps being the closest living relative. John Hawks offers a succinct reply, one which is supported by my (admittedly rushed) reading of the paper.

Ref: John R. Grehan & Jeffrey H. Schwartz. Evolution of the second orangutan: phylogeny and biogeography of hominid origins. Journal of Biogeography, 2009 DOI: 10.1111/j.1365-2699.2009.02141.x

Update (6/30): The paper is available online here.

Darwinius masillae gets out of control

May 20, 2009 1 comment

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Can’t help but feel that this is getting a little silly. Darwinius masillae is a nice beautifully preserved specimen, it’s an interesting specimen, but it’s not THE missing link. Bora has complete links to the media circus while Ed Yong puts it all in perspective.

For more on this, see:

  • The original paper: Franzen JL, Gingerich PD, Habersetzer J, Hurum JH, von Koenigswald W, Smith BH (2009) “Complete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology.” PLoS ONE 4(5): e5723. doi:10.1371/journal.pone.0005723
  • PZ Myers over at the Panda’s Thumb.
  • John Wilkins on missing links and ancestors.
  • Carl Zimmer asks the question, does Darwinius even exist? It appears that PLoS may not count as a valid venue to publish taxonomic work.

Somewhat predictably, Matt Nisbet approves of this “innovative strategy“. Given that, this quote by Phil Gingerich in The Australian is of interest:

[O]ne of Dr Hurum’s co-authors, University of Michigan paleontologist Philip Gingerich, said the team would have preferred to publish in a more rigorous journal such as Science or Nature.

Dr Gingerich told The Wall Street Journal: “There was a TV company involved and time pressure. We’ve been pushed to finish the study. It’s not how I like to do science”.

Media-driven science with a book, movie & website. Nisbet’s “going broad” strategy has seen the light of day. Just what we need.

Remembering Charlie Lockwood

April 27, 2009 Comments off

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My colleague and friend Kaye Reed has a nice remembrance of Charlie Lockwood in the current issue of Evolutionary Anthropology. I had reason to mention Charlie during my “Last Lecture” and will admit to getting a little choked-up. The article is unfortunately behind a paywall, but any good university library should have access.

[Review] Explaining Human Origins

July 27, 2008 1 comment

(This review appeared in the American Journal of Physical Anthropology in 2005)

As human beings, we like to tell stories–we are story-telling apes. As scientists, however, we tend not to see ourselves as telling stories for, we are led to believe, stories are mere fiction. Yet when faced with answering the question of why or how we became story-telling apes, we are often presented with a series of hypotheses with little empirical evidence to distinguish between them. In many ways, Wiktor Stoczkowski claims that it is because we are storytelling apes, and that because stories often represent cultural accretions, we are having so little success in generating a conclusive narrative about hominization.

Read more…

Sad news for the anthropology community

July 14, 2008 9 comments

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Very sad news for those of us who do physical anthropology. Charles (“Charlie”) Lockwood (University College London) was killed today in a motorcycle accident in London. He is survived by his parents and sisters.

Charlie was a talented morphologist both in the sense of being a descriptive anatomist and quantitative biologist. I met him in the late 90’s when he came to ASU’s Institute of Origins for a post-doc after completing his PhD at the University of Witwatersrand. He, Bill Kimbel and I shared the pain of rejected NSF grant proposals before receiving NSF money to study the use of geometric morphometrics to study temporal bone variation in hominins. Three papers resulted:

  • Lockwood,C.A., Lynch,J.M., Kimbel,W.H. (2002). Quantifying temporal bone morphology of great apes and humans: An approach using geometric morphometrics. Journal of Anatomy 201(6), 447-464.
  • Lockwood,C.A., Kimbel,W.H., Lynch,J.M. (2004). Morphometrics and hominoid phylogeny: Support for a chimpanzee-human clade and differentiation among great ape subspecies. Proceedings of the National Academy of Sciences USA 101(13), 4356-4360.
  • Lockwood,C.A., Kimbel,W.H., Lynch,J.M. (2005). Variation in early hominin temporal bone morphology and its implications for species diversity. Transactions of the Royal Society of South Africa 60(2), 73-77.

There was other research we intended to do but, somehow, with Charlie’s move to London in 2004 and all that involved, we never got round to it. He was soon to be returning to South Africa to take a position at Wits. I’m proud to have known Charlie as a colleague and a friend. He will be missed.

Update: Charlie gets a mention from Adam Yates, Anthropology.net, Greg Laden & John Hawks.

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