Lawn Chair Anthropology

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Topics in biological anthropology, with special focus on human evolution, paleontology, and evolutionary developmental biology (evo-devo).

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  • November 15, 2015
  • 12:58 PM

Bioanthro lab activity: Hominin brain size

by zacharoo in Lawn Chair Anthropology

Last week in my Human Evolution class we looked at whether we could estimate hominin brain sizes, or endocranial volumes (ECV), based on just the length and width of the bony brain case. Students took these measurements on 3D surface scans… … and then plugged their data into equations relating these measurements to brain size […]... Read more »

  • November 8, 2015
  • 08:40 AM

Osteology Everywhere: Bacon or first rib?

by zacharoo in Lawn Chair Anthropology

I went to a cafe today to eat breakfast and get some work done. It’s important to be properly nourished to ensure maximal productivity. But I was aghast to behold the food they placed before me: First of all, this is not a sufficient amount of bacon. Secondably, this bacon is a spitting image of a first rib: […]... Read more »

Lordkipanidze D, Jashashvili T, Vekua A, Ponce de León MS, Zollikofer CP, Rightmire GP, Pontzer H, Ferring R, Oms O, Tappen M.... (2007) Postcranial evidence from early Homo from Dmanisi, Georgia. Nature, 449(7160), 305-10. PMID: 17882214  

Schmid P, Churchill SE, Nalla S, Weissen E, Carlson KJ, de Ruiter DJ, & Berger LR. (2013) Mosaic morphology in the thorax of Australopithecus sediba. Science, 340(6129), 1234598. PMID: 23580537  

White TD, Asfaw B, Beyene Y, Haile-Selassie Y, Lovejoy CO, Suwa G, & WoldeGabriel G. (2009) Ardipithecus ramidus and the paleobiology of early hominids. Science, 326(5949), 75-86. PMID: 19810190  

  • November 7, 2015
  • 10:07 AM

Bioanthro lab activity: Sexual dimorphism

by zacharoo in Lawn Chair Anthropology

A few weeks ago we examined sexual dimorphism – characteristic differences between males and females – in my Intro to Bioanthro class. Sexual dimorphism roughly correlates with aspects of social behavior in animals, and so we compared dimorphism in our class with what is seen in other primates. For the lab, we collected our body masses, heights, […]... Read more »

  • October 31, 2015
  • 04:56 AM

Osteology everywhere: Halloween skull comet

by zacharoo in Lawn Chair Anthropology

It’s Halloween, a day when it’s socially acceptable for adults to play dress-up like children. Also, people celebrate things that are spooky-scary. So it’s perfect timing that NASA would announce that our planet will be visited by a dead comet, a celestial ghost hoping to haunt a planet full of the living. As NASA pointed out in […]... Read more »

  • October 30, 2015
  • 01:48 AM

Bioanthro lab activity: What species is it?

by zacharoo in Lawn Chair Anthropology

We’re learning about the divergence between robust Australopithecus and early Homo 2.5-ish million years ago in my Human Evolution class this week. Because of this multiplicity of contemporaneous species, when scientists find new hominin fossils in Early Pleistocene sites, a preliminary question is, “What species is it?” To help my students learn how we know whether […]... Read more »

  • October 25, 2015
  • 01:28 PM

Gracile & robust Australopithecus

by zacharoo in Lawn Chair Anthropology

Last week, I introduced my Human Evolution students to the “robust” australopithecines. It was a very delicate time, when we had to have a grown up, mature conversation about adult things. I reminded the students that they’re only human, but they must resist urges that seem only natural. No matter how much they want to, even if their friends are doing it, […]... Read more »

Asfaw B, White T, Lovejoy O, Latimer B, Simpson S, & Suwa G. (1999) Australopithecus garhi: a new species of early hominid from Ethiopia. Science (New York, N.Y.), 284(5414), 629-35. PMID: 10213683  

Domínguez-Rodrigo, M., Pickering, T., Baquedano, E., Mabulla, A., Mark, D., Musiba, C., Bunn, H., Uribelarrea, D., Smith, V., Diez-Martin, F.... (2013) First Partial Skeleton of a 1.34-Million-Year-Old Paranthropus boisei from Bed II, Olduvai Gorge, Tanzania. PLoS ONE, 8(12). DOI: 10.1371/journal.pone.0080347  

Haile-Selassie Y, Gibert L, Melillo SM, Ryan TM, Alene M, Deino A, Levin NE, Scott G, & Saylor BZ. (2015) New species from Ethiopia further expands Middle Pliocene hominin diversity. Nature, 521(7553), 483-8. PMID: 26017448  

Walker, A., Leakey, R., Harris, J., & Brown, F. (1986) 2.5-Myr Australopithecus boisei from west of Lake Turkana, Kenya. Nature, 322(6079), 517-522. DOI: 10.1038/322517a0  

  • September 13, 2015
  • 03:00 PM

Homo naledi in a lawn chair

by zacharoo in Lawn Chair Anthropology

It is a great relief that Homo naledi, a most curious critter, was announced to the world on Thursday. I’ve been working on these fossils since May 2014, and it was really hard to keep my trap shut about it for over a year. I was in London for the ESHE conference last week when **it […]... Read more »

Berger LR, Hawks J, de Ruiter DJ, Churchill SE, Schmid P, Delezene LK, Kivell TL, Garvin HM, Williams SA, DeSilva JM.... (2015) Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa. eLife. PMID: 26354291  

  • September 6, 2015
  • 06:00 AM

A new year of bioanthro lab activities

by zacharoo in Lawn Chair Anthropology

One of my goals in teaching is to introduce students to how we come to know things in biological anthropology, and lab activities give students hands-on experience in using scientific approaches to address research questions. Biological anthropology (really, all biology) is about understanding variation, and I’ve created some labs for students to scrutinize biological variation within the classroom. In my Introduction class, the first aspect of […]... Read more »

  • August 23, 2015
  • 08:52 AM

Easter Eggs from Raymond Dart

by zacharoo in Lawn Chair Anthropology

Some of the more colorful ideas and text in the anthropological literature are courtesy of Raymond Dart. In 1925, Dart identified the Taung fossil as a close relative of humans, and coined the scientific name, Australopithecus africanus. This was a pretty good idea, as Taung was the first in what is now a large collection of fossils attributed to this […]... Read more »

  • July 11, 2013
  • 02:10 PM

Update: Brain growth in Homo erectus, and the age of the Mojokerto fossil

by zacharoo in Lawn Chair Anthropology

The Mojokerto calvaria. You're looking at the left side of the skull: the face would be to the left. Check it out in 3D here.A few months ago I posted an abridged version of the presentation I gave at this year's meetings of the American Association of Physical Anthropologists, about brain growth in Homo erectus. This study, co-authored with Jeremy DeSilva, adopts a novel approach (see "Methods" in that earlier post) to analyze the Mojokerto fossil (right). The specimen is the only H. ........ Read more »

  • June 19, 2013
  • 12:54 AM

We like turtles ('s genomes)

by zacharoo in Lawn Chair Anthropology

June 2013, Volume 45 No 6 pp 579-714Jonathan the zombie isn't the only one who likes turtles. These heroes-in-a-half-shell adorn the cover of the current Nature Genetics, as two species of turtle have just joined the Genome Club (Wang et al. 2013; paper's free!).This definitely not one of those genome sequencing studies alluded to recently by John Hawks, that's "too boring for journals." Wang and colleagues didn't just sequence the genomes of soft-shell and green sea tur........ Read more »

  • May 12, 2013
  • 05:01 AM

Online skeletal and dental datasets (links links links!)

by zacharoo in Lawn Chair Anthropology

Jean Jacques Hublin has a commentary [1] in the current issue of Nature, about making fossils available for scanning, digital replication, and ultimately hopefully open dissemination. As Hublin points out, it's a bit ridiculous that a fossil is a rare enough thing as it is, but even after their discovery, fossils "can become unreachable relics once they are in storage." Fortunately, Hublin goes on to point to online collections that are available to anyone interested. Somewhat ironically, t........ Read more »

  • May 11, 2013
  • 09:43 AM

Arm and leg modelling

by zacharoo in Lawn Chair Anthropology

No, I'm not looking for people with lithe limbs to be photographed for money. Much more sexily, I'm referring to a recent paper (Pietak et al., 2013) that's found that the relative length of the segments of human limbs can be modeled with a log-periodic function:Figure 2 from Pietak et al. 2013. Human within-limb proportions are such that the length of each segment (e.g., H1-6) of a limb, from  fingertip to shoulder (A) and to to hip (B), can be predicted by a logarithmic periodic function&........ Read more »

  • April 16, 2013
  • 03:05 PM

Pre-publication: Brain growth in Homo erectus (plus free code!)

by zacharoo in Lawn Chair Anthropology

The annual meetings of the American Association of Physical Anthropologists were going on all last week, and I gave my first talk before the Association. The talk focused on using resampling methods and the abysmal human fossil record to assess whether human-like brain size growth rates were present in our >1 mya ancestor Homo erectus. This is something I've actually been sitting on for a while, but wanted to wait til the talk to post for all to see. Here's a brief version:Background: Hu........ Read more »

Coqueugniot H, Hublin JJ, Veillon F, Houët F, & Jacob T. (2004) Early brain growth in Homo erectus and implications for cognitive ability. Nature, 431(7006), 299-302. PMID: 15372030  

Herndon JG, Tigges J, Anderson DC, Klumpp SA, & McClure HM. (1999) Brain weight throughout the life span of the chimpanzee. The Journal of comparative neurology, 409(4), 567-72. PMID: 10376740  

Sakai T, Matsui M, Mikami A, Malkova L, Hamada Y, Tomonaga M, Suzuki J, Tanaka M, Miyabe-Nishiwaki T, Makishima H.... (2013) Developmental patterns of chimpanzee cerebral tissues provide important clues for understanding the remarkable enlargement of the human brain. Proceedings. Biological sciences / The Royal Society, 280(1753), 20122398. PMID: 23256194  

  • February 28, 2013
  • 12:19 PM

Go home, RNA, you're drunk

by zacharoo in Lawn Chair Anthropology

(Alternate title: "circRNA censors the RNA censors?")When I was a kid, RNA played second fiddle to DNA. RNA was a mere intermediary between the 'book of life' (DNA) and the stuff the book coded for (proteins). But in the years since, RNA has shown itself to be a key player in the regulation of gene expression (shut up, DNA!). We now know of lots of kinds of non-coding RNA (ncRNA) that do lots of important things in cells, such as maintaining genomic integrity in the germ line (piRNA) a........ Read more »

Hansen, T., Jensen, T., Clausen, B., Bramsen, J., Finsen, B., Damgaard, C., & Kjems, J. (2013) Natural RNA circles function as efficient microRNA sponges. Nature. DOI: 10.1038/nature11993  

Memczak, S., Jens, M., Elefsinioti, A., Torti, F., Krueger, J., Rybak, A., Maier, L., Mackowiak, S., Gregersen, L., Munschauer, M.... (2013) Circular RNAs are a large class of animal RNAs with regulatory potency. Nature. DOI: 10.1038/nature11928  

  • February 20, 2013
  • 10:49 PM

The shale revolution & lying with statistics

by zacharoo in Lawn Chair Anthropology

Is U.S. energy independence, based in part on 'fracking' shale deposits to access oil and gas reservoirs, just a pipe dream? A comment by JD Hughes in this week's Nature posits just this, pointing out that production at most of these deposits declines steeply in just a few years - the industry is simply not sustainable. But why all the hype around such an unsustainable resource?In my view, the industry practice of fitting hyperbolic curves to data on declining productivity, and inferring li........ Read more »

  • February 2, 2013
  • 12:04 AM

The "human" genome?

by zacharoo in Lawn Chair Anthropology

The topic this week in my Intro to Bioanthro course is genetics, with the subtheme being the mechanisms getting us from a genotype to "the" human phenotype (next week is variation and population genetics). Of course we talked about things like DNA, simple Mendelian inheritance (even though many traits/diseases probably aren't really Mendelian), and even epigenetics and genomic imprinting. But I also wanted to point out the many ways that our very existence relies of life extrinsic to that encode........ Read more »

Gilbert, S., Sapp, J., & Tauber, A. (2012) A Symbiotic View of Life: We Have Never Been Individuals. The Quarterly Review of Biology, 87(4), 325-341. DOI: 10.1086/668166  

Smith MI, Yatsunenko T, Manary MJ, Trehan I, Mkakosya R, Cheng J, Kau AL, Rich SS, Concannon P, Mychaleckyj JC.... (2013) Gut Microbiomes of Malawian Twin Pairs Discordant for Kwashiorkor. Science. PMID: 23363771  

van Nood E, Vrieze A, Nieuwdorp M, Fuentes S, Zoetendal EG, de Vos WM, Visser CE, Kuijper EJ, Bartelsman JF, Tijssen JG.... (2013) Duodenal infusion of donor feces for recurrent Clostridium difficile. The New England Journal of Medicine, 368(5), 407-15. PMID: 23323867  

Yatsunenko T, Rey FE, Manary MJ, Trehan I, Dominguez-Bello MG, Contreras M, Magris M, Hidalgo G, Baldassano RN, Anokhin AP.... (2012) Human gut microbiome viewed across age and geography. Nature, 486(7402), 222-7. PMID: 22699611  

  • January 28, 2013
  • 10:32 PM

Open wide for open access: chimpanzee tooth eruption

by zacharoo in Lawn Chair Anthropology

Two anthropology papers came out yesterday in advance print at the Proceedings of the National Academy of Sciences. I'd like first to draw your attention to the fact that they're open access - normally such scientific papers are behind a paywall, but these two can be obtained by anyone (well, anyone with internet). One is about the chronology and nature of Acheulean technology at the 1.7-1.0 mya site of Konso in Ethiopia. The other, and the subject of this post, is about life history in wild chi........ Read more »

Smith TM, Smith BH, Reid DJ, Siedel H, Vigilant L, Hublin JJ, & Boesch C. (2010) Dental development of the Taï Forest chimpanzees revisited. Journal of human evolution, 58(5), 363-73. PMID: 20416929  

Smith, T., Machanda, Z., Bernard, A., Donovan, R., Papakyrikos, A., Muller, M., & Wrangham, R. (2013) First molar eruption, weaning, and life history in living wild chimpanzees. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1218746110  

Zihlman A, Bolter D, & Boesch C. (2004) Wild chimpanzee dentition and its implications for assessing life history in immature hominin fossils. Proceedings of the National Academy of Sciences of the United States of America, 101(29), 10541-3. PMID: 15243156  

  • November 27, 2012
  • 02:39 PM

A new method for analyzing growth in extinct animals (dissertation summary 1)

by zacharoo in Lawn Chair Anthropology

The last year and a half was a whirlwind, and so I never got around to blogging about the fruits of my dissertation: Mandibular growth in Australopithecus robustus... Sorry! So this post will be the first installment of my description of the outcome of the project. The A. robustus age-series of jaws allowed me to address three questions: [1] Can we statistically analyze patterns of size change in a fossil hominid; [2] how ancient is the human pattern of subadult growth, a key aspect of our ........ Read more »

  • September 30, 2012
  • 01:45 AM

Malaria, sickle-cell anemia and microRNA

by zacharoo in Lawn Chair Anthropology

This is the first time I'm teaching Introduction to Biological Anthropology here at Nazarbayev University. It's exciting and curious that for nearly every class session, I'm able to find a very recent outside article or blog post that's relevant to the field and/or something we're talking about at the moment. For instance, the 30-paper barrage of the ENCODE project came out right as we were beginning the unit focused on evolution and genetics. Serendipity!Recently in this first unit, w........ Read more »

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