The Caveman’s Corner

According to G. Reagan and C. Ross in a study published in Folia Primatologica 71 and reported in the latest issue of Current Anthropology, twins of Wied’s black tufted ear marmosets share a significant amount of genetic information while in the womb. They’re chimeras.

To quote the report:

Starting on the nineteenth day of development and ending by the twenty-ninth, the placentas of twins begin to fuse. During this time, the twins exchange stem cells that carry with them their genetic makeup, with the result that individuals possess both cells inherited at conception that contain the original DNA of their parents and other cells that contain the DNA of their fraternal twins. This pattern, known as chimerism, was found in all bodily tissues sampled, including reproductive gametes. In one instance, a female marmoset passed on her twin brother’s DNA to her offspring, making her children her genetic nieces or nephews.

This has implications for the marmoset pattern of child rearing which involves extensive parental investment, especially by the father.

Because of the stem cell exchange between twins, individuals in a marmoset family group may share more than 50% of their genetic information (the typical degree of relatedness between parents and their offspring or between siblings). This creates a situation in which family members may have more invested in their offspring or siblings than predicted for other species—a possibility that will greatly affect the present understanding of how genetics and behavior interact.

Marmosets aren’t just their brother’s keeper. They’re their brother’s father.

After a long hiatus, I bring you another installment of “Meet a Contemporary.” Yayyyyy. School’s out now, so this blog should pick up a bit.

Meet Callitrhix (sometimes Cebuella) pygmaea, or the pygmy marmoset, a contender with the gray mouse lemur, lesser galago, and pygmy tarsier for smallest living primate. They’re cute little buggers and often kept in private homes as pets in the West (not a practice primatologists are favorable towards). For those two reasons, the pygmy marmoset might well be familiar to the reader.

Awww.

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Yet again, I’m contemplating embarking forth on a research project. Who knows how far this one will go, as my last… several… have died after I got overwhelmed by the preliminary reading. I do think this project has some distinct advantages, however: A) I now have access to the UT database at home on my computer, B) I can do this project without getting approval ahead of time (like with a zoo study), C) I won’t need too much math, I hope, and D) The study might be one that is fully within my resources to carry out.

What I was thinking of is a genealogical study to test the ‘Grandmother Hypothesis.’ For those not familiar, the grandmother hypothesis holds that the long human female post-reproductive lifespan evolved because grandmothers would aid their offspring in raising their children and thus increase their own reproductive success. Was this process active in recent societies? Well, to answer that, my plan is to examine genealogical records from Sevier and surrounding counties where I live. Fortunately, Appalachian people have a taste for this sort of thing, so genealogies aren’t excessively hard to come by. There are a lot of families with very long histories here as well that can be tracked back centuries in a single county. As for the specific methodology of analysis… I’ve found one other study of this type down in a Japanese city, and I’m planning to see how much I can apply from it. Any suggestions would be most welcome.

Oh, my poor blog… I have neglected thee so. And I’ve stopped reading them too. I don’t know why exactly. I still want to blog. The desire has not left me. I just seem to be in a rut. I still haven’t started the Meet a Contemporary I should be doing, not because I’ve been particularly to busy but just because it always seems like I should have started earlier. Ahhh. Oh well. At least this is a post. Yes! The spell is broken! Blog ho!

Ah, but I have that powerpoint to do… And its not due at a soon enough date for me to be procrastinating by working much harder on something else. But actually, I have something I could blog on now. So ha! Rise like a Phoenix, dear blog!

http://www.expelledexposed.com/

This is a site created by the National Center for Science Education to debunk and disembowel the various fantasies at the heart of Ben Stein’s new docuganda piece Expelled: No Intelligence Allowed. And it does it quite nicely I must say. I rather recommend.

I got my UT account to work! Thus I now have access to all the wonderful journals and databases. I came across an interesting article searching Central Issues in Anthropology today, by a Robert B. Tincher and thought I would share.

Night Comes to the Chromosomes: Inbreeding and Population Genetics in Southern Appalachia

Good ol’ uncle brother first cousin Pappy

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This is a concept that reading Dennison’s Nash A Little Anthropology, 3rd ed has acquainted me with, and its extremely interesting. I don’t believe I’ve ever specifically considered it before.

Such a stoic.

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I have a question I would like to ask the world:

?

What is this supposed to be? There is no monkey that looks like that. There is no animal on earth that looks like that. Why is this (basically) what everyone thinks of when they hear “monkey”?

As far as I can figure out, it looks sort of like a cartoony chimpanzee (Curious George maybe?) with a tail randomly stuck on. Not that chimpanzees are that color. There are some macaques that have vaguely that color of fur by they all have bright colorations on their exposed skin. There aren’t that many brown monkeys, honestly. Maybe a spider monkey except the proportions are all wrong.

I guess that’s what those are. Fracked up, brown spider monkeys. I want to get an ethnozoologist onto how on earth that’s come to be the number one public image of “primate.” *sigh*

I finished Amir Aczel’s The Jesuit and the Skull: Teilhard de Chardin, Evolution, and the Search for Peking Man today, and I decided to write up a review/reflection sort of thing. I haven’t decided exactly which yet. I’ve thought about adding a feature like this before and I enjoyed doing it, so you might conceivably see more reviews.

From Amazon, obviously

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So the whole weekly thing is pretty much out the window. I’ve been experiencing some technical difficulties for a while and I’ve had other matters to attend to/lacked motivation. But, you may unbate your breath, we have Meet an Ancestor entry number two: Propliopithecus chirobates.

A reconstruction of Propliopithecus

Woohoo, we finally got our super-obscure species that Google hasn’t heard of (Did you mean: propliopithecus chorobates). It is, however, a member of a quite famous and extremely important lineage.

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