One principal component to rule them all?
Despite the reality that I’ve cautioned against taking PCA plots too literally as Truth, unvarnished and without any interpretive juice needed, papers which rely on them are almost magnetically attractive to me. They transform complex patterns of variation which you are not privy to via your gestalt psychology into a two or at most three […]
Disease as a byproduct of adaptation
How we perceive nature and describe its shape are a matter of values and preferences. Nature does not take notice of our distinctions; they exist only as instruments which aid in our comprehension. I’ve brought this up in relation to issues such as categorization of recessive vs. dominant traits. The offspring of people of […]
More Jews, fewer markers
At around the same time that the two big Jewish genetics papers came out, there was another one in BMC Genetics which I had overlooked. It’s open access so you can read the whole thing, but seems like they used 32 STR’s as markers. Their primary finding about Jewish populations was that there was a […]
The Price of Altruism
Sometimes in a narrative you have secondary characters who you want to revisit. What do to do after the story is complete? An convenient “work-around” to this problem is to find the story rewritten from the perspective of the secondary character. In broad strokes the picture is unchanged, but in the finer grained shadings different […]
Dispute over longevity research getting more coverage
Earlier this week I pointed to the controversy which has erupted around the widely reported new paper, Genetic Signatures of Exceptional Longevity in Humans. Newsweek did the most thorough early reporting, but now The New York Times has published a follow up story covering the scientific criticisms to the original paper’s methodology. There’s nothing new […]
The short life expectancy of longevity genes (?)
When I first heard in the media there was a new study of longevity which had produced a model based on your SNP profile that was “77% accurate” as to whether you’d live to the age of 100 or not, I assumed this was confusion or distortion (perhaps The Daily Mail had broken embargo first […]
Don’t genetically profile yourself just yet…perhaps
Newsweek has a long piece up which reviews some major issues with the new study of centenarians that’s been all over the media right now. Ed Yong already covered the paper, but I’m going to look at the details myself. Here’s a update from the Newsweek post:
Within an hour of this story’s publication, the Science […]
Why Tibetans breathe so easy up high
I said yesterday I would say a bit more about the new paper on rapid recent high altitude adaptation among the Tibetans when I’d read the paper. Well, I’ve read it now. Sequencing of 50 Human Exomes Reveals Adaptation to High Altitude:
Residents of the Tibetan Plateau show heritable adaptations to extreme altitude. We sequenced […]
More markers, or more populations?
Here’s a letter to The American Journal of Human Genetics worth reading, Genetic Landscape of Eurasia and “Admixture” in Uyghurs:
…In the papers…by Xu and Jin, the genetic structure of Uyghurs was described by 8150 ancestry-informative markers (AIMs). These markers estimated the admixture rate of the Uyghur population to be around 50% East Asian ancestry by […]
Very recent altitude adaptation in Tibet
Nick Wade in The New York Times is reporting on a new paper which will come out in Science tomorrow which investigates the evolution of genes implicated in adaption to higher altitudes among Tibets. I’ve posted on the genetics of this topic before, it obviously is of great interest. The major new finding is that […]
Hamilton’s Rule vs. Increasing returns to cooperation
If you have even a marginal interest in evolutionary biology you will probably have heard of Hamilton’s Rule, a simple formal representation of the logic whereby a gene which favors altruism may spread through a population: rB > C, where r = coefficient of relatedness on the gene in question, B = benefit to those […]
Amerindians of Brazil more numerous than you think
A few months ago I was thinking a fair amount about the Neandertals. One issue which became more stark to me due to that particular finding, that a few percent of the human genome seems to have derived from Neandertal populations, is the reality that genetic distinctiveness can persist long after cultural coherency is no […]
The English & Irish, together again
One of the peculiarities of the synthesis of 19th and early 20th historical linguistics and biological anthropology was the perception by many British thinkers that the English, as the scions of the Anglo-Saxons, were fundamentally a different race from the Celtic nations to their west, the Welsh and Irish, and the Scots to the north […]
Cuckoldry more common in past generations
We have some data that in fact older generations were more sexually promiscuous, contrary to the moral panic perpetually ascendant. As a follow up to my previous post, there is some scholarship which suggests that misattributed paternity rates have been declining. Recent decline in nonpaternity rates: a cross-temporal meta-analysis:
Nonpaternity (i.e., discrepant biological versus social fatherhood) […]
The paternity myth: the rarity of cuckoldry
An urban myth, often asserted with a wink & a nod in some circles, is that a very high proportion of children in Western countries are not raised by their biological father, and in fact are not aware that their putative biological father is not their real biological father. The numbers I see and hear […]
The “how” of cystic fibrosis through the “why”
It’s just a fact that contemporary human evolutionary genetics has relied upon its potential insights into disease to generate funding, support and interest. I don’t think that this is much of a silver lining when set next to the suffering caused by disease, but it’s a silver lining nevertheless. Therefore findings which would be of […]
Science is sufficient for any inference
Because I’m a generally somewhat more anthropocentric in regards to my interest in the “squishy science” I am often amused by the wide range of inferences that people make when presented with a set of scientific results. Naturally, when I talk about the genetics of Jews it gets a lot more heated. You did not […]
Jews and genetics
Over at Discover Blogs I have a very long post up on Jews & Genetics. In particular the recent paper in AJHG. One observation I have to make about Jewish genetics: when it comes to PCA plots which illustrate the relationship of Jews, in particular Ashkenazi Jews, to other populations I’ve noticed that two different […]
Grizzly-Polar bear hybrids in the wild
Timely, Pizzly Bears: Scientists confirmed last week that a bear shot by an Inuvialuit hunter in the Northwest Territories is a second-generation grizzly-polar bear hybrid—a “pizzly” or “grolar” bear. Not that big of a deal. It is likely that polar bears are simply a recent derived variant of brown bear. The main issue not noted […]
Who are the living Neandertals?
I guess now we kind of know.