(no subject)
Hey, I actually remember what I said last time! Because it hasn't been 8 million years.
Now I am OFFICIALLY done with my first year of grad school, and yes, it's not a FULL year, just an academic one, but the summer is just labyay and insect camp, so I can deal with that. Spent the past three days (work days, that is) cleaning and reorganizing the new lab, since we had sort of a big turnover this year -- the senior student defended, four undergrads graduated and two new grads joined (me and a BioSci direct admit), leaving a third year as the only holdout. But Third Year is an agreeable sort, so he was happy for us to...um, take over. BUT. It looks SOPRETTY. Drawers are LABELED, and they contain the things that the label claims they do! Benches are clean and organized! Desks are assigned! We're proud of ourselves, but we still need to clean out the freezers, so the work isn't done yet.
Oh, right, and that paper I'm supposed to have written in a month. Um.
OH. I HAVE A POLL.
Poll
I'm SURE you heard, LJ, that Neandertals and modern humans got it on, but because Neandertals never went to Africa, it was only the modern humans who left that fair continent that were privy to the caveman action. The science is super cool, but before I give a synopsis, let me name drop and say that not only did I see the orchestrating scientist on the two Neandertal genome Science papers speak just a couple hours after the papers went live, I got to have lunch with him! His name is Svante Paabo and he is Swedish and kind of adorable and we fed him sweet tea for the first time and it was SOCOOL.
'kay, science. There were a couple independent analyses of the data, but the gist of it is that our technology allowed them to sequence around 60% of the Neandertal genome from DNA extracted from the bones of three individuals found in the same cave. So they compared variation between Neandertal, African and Craig Venter's genome and saw that at loci where evolution is slow, the Neandertal was significantly closer to Venter (the European) than to the African. Now, there is no evidence that Neandertal genes were selected for; that is, their rate of evolution is similar to the DNA surrounding it and what it looks like is that my 1-4% is probably composed of different fragments than your 1-4%. No advantage to having caveman lineage, therefore, it's just cool.
LOTS of questions, though: No gene flow was detected going the other way: no human genes in Neandertal (no more than the large fragment we share ANYWAY, that is), and very interestingly, no Neandertal mitochondrial DNA in humans. Now, the lack of human genes in Neandertal could well be sampling bias. We only had three individuals to work with and they were likely related. Could their ancestors have been secluded? Are they too old to have been the recipients of gene flow (maybe the human mating hadn't started yet). But with more individuals and more of the genome, those questions should be answered. But what about the mitochondria? How could we have nuclear genes, but not those? It could come back to the ways these genes are passed on. The nuclear genome is a combination of the mother and father, right, with both contributing roughly 50% of the total genetic material. However, the mitochondrial genome is maternally transmitted (the seed mitochondria for the embryo are all contained in the egg, and very few, if any, mitochondria from the sperm would infiltrate). One possible thought is that if the matings were often fleeting or nonconsensual, the hybrid children were most likely to stay with the mother, and thus kids with human mothers and Neandertal fathers would have maternal mitochondria -- human. But that's only speculation. What's cool about the speculation, though, is that it bridges strongly modern biology with anthropology: the more we know about how early human European tribes and Neandertal tribes lived and interacted, the more confident we can be about our interpretation of biological and genetic data.
<3
Now I am OFFICIALLY done with my first year of grad school, and yes, it's not a FULL year, just an academic one, but the summer is just labyay and insect camp, so I can deal with that. Spent the past three days (work days, that is) cleaning and reorganizing the new lab, since we had sort of a big turnover this year -- the senior student defended, four undergrads graduated and two new grads joined (me and a BioSci direct admit), leaving a third year as the only holdout. But Third Year is an agreeable sort, so he was happy for us to...um, take over. BUT. It looks SOPRETTY. Drawers are LABELED, and they contain the things that the label claims they do! Benches are clean and organized! Desks are assigned! We're proud of ourselves, but we still need to clean out the freezers, so the work isn't done yet.
Oh, right, and that paper I'm supposed to have written in a month. Um.
OH. I HAVE A POLL.
Poll
I'm SURE you heard, LJ, that Neandertals and modern humans got it on, but because Neandertals never went to Africa, it was only the modern humans who left that fair continent that were privy to the caveman action. The science is super cool, but before I give a synopsis, let me name drop and say that not only did I see the orchestrating scientist on the two Neandertal genome Science papers speak just a couple hours after the papers went live, I got to have lunch with him! His name is Svante Paabo and he is Swedish and kind of adorable and we fed him sweet tea for the first time and it was SOCOOL.
'kay, science. There were a couple independent analyses of the data, but the gist of it is that our technology allowed them to sequence around 60% of the Neandertal genome from DNA extracted from the bones of three individuals found in the same cave. So they compared variation between Neandertal, African and Craig Venter's genome and saw that at loci where evolution is slow, the Neandertal was significantly closer to Venter (the European) than to the African. Now, there is no evidence that Neandertal genes were selected for; that is, their rate of evolution is similar to the DNA surrounding it and what it looks like is that my 1-4% is probably composed of different fragments than your 1-4%. No advantage to having caveman lineage, therefore, it's just cool.
LOTS of questions, though: No gene flow was detected going the other way: no human genes in Neandertal (no more than the large fragment we share ANYWAY, that is), and very interestingly, no Neandertal mitochondrial DNA in humans. Now, the lack of human genes in Neandertal could well be sampling bias. We only had three individuals to work with and they were likely related. Could their ancestors have been secluded? Are they too old to have been the recipients of gene flow (maybe the human mating hadn't started yet). But with more individuals and more of the genome, those questions should be answered. But what about the mitochondria? How could we have nuclear genes, but not those? It could come back to the ways these genes are passed on. The nuclear genome is a combination of the mother and father, right, with both contributing roughly 50% of the total genetic material. However, the mitochondrial genome is maternally transmitted (the seed mitochondria for the embryo are all contained in the egg, and very few, if any, mitochondria from the sperm would infiltrate). One possible thought is that if the matings were often fleeting or nonconsensual, the hybrid children were most likely to stay with the mother, and thus kids with human mothers and Neandertal fathers would have maternal mitochondria -- human. But that's only speculation. What's cool about the speculation, though, is that it bridges strongly modern biology with anthropology: the more we know about how early human European tribes and Neandertal tribes lived and interacted, the more confident we can be about our interpretation of biological and genetic data.
<3