Radiolab

Re: Karen Keegan. Two tests I would have liked to see - A comparison between Karen's two DNA samples with that of her parents, and the same test of her children relative to their grandparents.

Scott,

The doctors did compare the son's DNA to Karen's mother and two brother, though unfortunately Karen's father had passed away by that time. And they did find that the sons were related to her larger family. To my knowledge, they never compared Karen's second set of DNA to the family, I believe beceause they felt the twin explanation was pretty clear and they didn't want to keep poking and prodding Karen.

Soren.

I'm transgendered. I wonder if anyone has explored the idea that perhaps transgendered people could be chimeras. Could I actually have the DNA of both a man and a woman in me? Has anyone heard of research into this?

TGAlison: It's not likely but certainly possible. Chimerism includes a number of specific intersexual conditions and a simple DNA test will check. I'm curious: what parts do you think are those of your never-born fraternal sister? Or brother?

TG is even less specific than "chimerism," because it's not a medical diagnosis, but a social rubric, and rather a broad one at that. There are all sorts of medical conditions that can encourage gender identity issues - adrenal hyperplasia, androgen sensitivity, hermaphoditism. And there are people who just like to play dress-up who call themselves TG.

Now hermaphroditism can be a symptom of chimerism, but you can be certain through DNA testing. One generally sees skin abnormalities in cases of chimerism. They follow what are called "Blaschko's Lines." And certainly other intersexual components occur, like testes in some women, ovaries in men, or ovotestes, and the like...

where can we see pictures of the Geep?

I'd love to listen to this show, but I can't find the audio link anywhere, even though the show was a week ago. Could someone post it, or be so kind as to tell me how to find it? (Apologies in advance if it is obvious and I am somehow missing it.)

Blake,

Unfortunately, there's a little time lag between the show going on the radio and being available on the website or through podcast. But it will be up in the next couple weeks and we'll post a blog when it's ready.

Sorry for the wait.

Another great Radio Lab episode. Keep up the good work. Radio Lab is up there with This American Life as one of my top shows.

The Karen Keegan segment was especially good and quite moving.

Great Show! I always look forward to the new episodes. I am a little confused about the link to the jewelry website.... Is that a mistake? Just curious - I wanted to see who was selling Pegasus wings.....

Thanks!

Snacky O

Thank you for an interesting show. As a science teacher, I have a couple picky comments on one statement, from the human/chimp chimera discussion:

"Well there once was a creature like that, because if you believe in evolution you believe that chimps eventually became humans"

One big misconception about evolution is it claims that "humans evolved from monkeys." Humans and chimpanzees are genetically similar because they share a common ancestor. (PBS has a good evolution site with more info on this distinction: http://www.pbs.org/wgbh/evolution/library/faq/cat02.html)

I'm also leery of the phrase "believe in evolution." Evolution is a scientifically testable and supported theory, in contrast to faith-based fields of thinking that require belief. As with every other field of science, the study of evolution is not about belief. It is about evidence.

Perhaps these seem like small distinctions, but I hate to see a science show perpetuating misinformation about such an unnecessarily divisive issue.

I love Radiolab, and regret that so few episodes can be produced each season. But this segment included a statement by Robert K. that was, as far as I know, totally unscientific, and even dangerous.

It concerned the discussion of creating a human-chimp chimera (at pproximately minute 16). Robert said that "if you believe in evolution, you believe that chimps eventually became humans. And so somewhere in history, there's someone who was 10% chimp and 90% human...".

This idea that evolution claims that humans descend from apes is one of the fallacies used by creationists in their attacks on Darwinism. I "believe" in evolution, and according to what I've been taught, humans and apes descend from a common ancestor; one does not descend from the other. That's a very big difference. Human evolution is not about becoming less ape-like, it's about becoming more human, just a chimp evolution is about becoming more chimp-like.

We need a correction!!!!!!

And about Lee Silver's comments: he said that he discussed with his students a possible human-chimp chimera, and which characteristics of the chimera would come from the human and which from the chimp. But in the earlier section on the geeps, it was clear that there is absolutely no way of predicting the characteristics of the chimera, and that each one was different, based on the development of the embryonic cells coming from either the sheep or the goat. Can you explain this apparent discrepancy?

Ooops. I missed Jennifer's comment saying the same thing as my 4:15 post. At least I'm not alone in finding this bit wrong.

Marc and Jennifer (and all),

You are quite right. Unfortunate that I let this slip by. Lee Silver did try to correct Robert by noting that humans developed slowly over millions of years from a chimp-like ancestor, and at each step along the way the offsrping were similar to their parents ... but we cut him a bit short and Robert's comment was still off the mark.

Thanks for catching this and keeping us on our toes.

Marc, Re: Silver's talk with his students, I don't think he was actually asking them to predict the characteristics, just prompting them to think about the myriad possibilities and the consequences of those possibilities.

Thanks again, and sorry we slipped up on this one.

Cheers,

Soren.

I would like to second the request for geep pictures!

In re the chimp/human comments:

Absolutely correct about "common ancestor," not a human coming from a chimp. People seem to have a hard time talking about time when it comes to evolution. There was quite possibly a time where there were species between what we call a chimp and what we call a human today. Or, something that looked like neither.

And careful: we're not talking about a chimera human/chimp, but a hybrid human/chimp - the product of a mating of a human and a chimp. A chimera human with chimp cells or organs would still act like a human. And vice versa. 23 Chromosomes from the human, 24 from the chimp (because chimps have 48), or 23, if they could induce a turner-syndrome like dropping of the sex chromosome.