razib | May 19, 2006Well...the title is a little creepy, but sums up the melange in this report, Study finds that a woman's chances of having twins can be modified by diet. But there is more than diet, researchers have long known that genetics plays a role in twinning rates, it is heritable in that some proportion of the population variation correlates with genotypic variation. And we also know that the rise of fertility medicine has resulted in a boom of multiple births in the modern world. Twinning then neatly encapsulates the manifold aspects of many phenomena of interest which exhibit a biological angle.…
razib | May 18, 2006My attempt to solicit a narrow and eminent list of evolutionary biologists for my planned attempt at rolling my own quizilla at some point in the future really got out of control. On the one hand, the discipline was too broadly construed. Biases creep in. On the other hand, the category was too narrow in that many scientists contributed to evolutionary biology without being evolutionary biologists (most trivally G.H. Hardy). Since many readers of this weblog are highly credentialized in some particular field, I invite all to:
1) State a category where you know your shit (e.g., "evolutionary…
razib | May 18, 2006Check out this post from Ed Brayton on a definition for "cultural racism" from the Seattle Public Schools:
Examples of these norms include defining white skin tones as nude or flesh colored, having a future time orientation, emphasizing individualism as opposed to a more collective ideology, defining one form of English as standard, and identifying only Whites as great writers or composers.
As someone who isn't "flesh colored" (see picture to your left, you know you got to love the hot chocolate!) and has lived in the Pacific northwest of the United States for over 15 years, I will weigh in…
razib | May 18, 2006This weeks "Ask a Science Blogger" question is:
"If you could shake the public and make them understand one scientific idea, what would it be?"
I assume others will answer this also, so I want to get this out first: my reply is that the public needs to know that the most important idea about "science" is that it is not about ideas, but it is a way of getting to those ideas through a specific way of thinking about the world and interacting with your fellow human. Science is the means, not the ends. And, that means is a synthesis of a set of heuristics mediated by a particular social context…
razib | May 18, 2006In the comments below in regards to the great evolutionary biologists, and the "Top 10 list," I received some good submissions. But, there is definitely (in my mind) a top tier which I am inflexible about.
Darwin - he basically invented the field as a science, made some darn good predictions (H. sapiens as an African species) and put forward ideas that are today being taken up again (sexual selection)
R.A. Fisher - Not only did he fuse Mendelian genetics with evolutionary biology ("biomemtrics"), and so lay the foundation for the Modern Synthesis, he is also the father of statistics
Sewall…
razib | May 17, 2006Your nominations? Mine below....
Charles Darwin
R.A. Fisher
Sewall Wright
J.B.S. Haldane
Motoo Kimura
Ernst Mayr
Richard Lewontin
J. M. Smith
W.D. Hamilton
Theodosius Dobzhansky
I chose based on subjective criteria, and the individuals above differ a great deal. Lewontin has done good work, but mostly I put him on the list because I think the paper co-authored with Hubby in the 1960s was an inflection point which signalled the end a long period of torpidity. I don't think much of Mayr's theoretical projects (see the problems with his "genetic revolutions" or "founder flush" verbal models,…
razib | May 17, 2006Ah...busy with other things, and Evolgen pounced on this story of hybrdization in the midst of the split between the pre-human and pre-chimpanzee lineages 5-7 million years ago. Carl Zimmer offers some social perspective, while John Hawks tears into the science (tears, cuts and bludgeons, actually).
I don't know about the details of the science here, there is a lot of exciting hype. Talk of human-chimpanzee hybridization is trangressive and appeals to our folk mythologies of man-apes. I also know that only one chimpanzee fossil has been recovered, and the pre-Australopithecene history of…
razib | May 17, 2006This dovetails nicely with my previous post on encephalization. Brain size not linked to Microcephalin and ASMP?. Normal Variants of Microcephalin and ASPM Do Not Account for Brain Size Variability:
Normal human brain volume is heritable. The genes responsible for variation in brain volume are not known. Microcephalin (MCPH1) and ASPM (abnormal spindle-like microcephaly associated) have been proposed as candidate genes since mutations in both genes are associated with microcephaly and common variants of each gene are apparently under strong positive selective pressure. In 120 normal…
razib | May 16, 2006At least 6 known murders this spring. How many more unsolved mysteries? How many nests rendered empty?
razib | May 16, 2006Between 3 million & 200,000 years ago the average cranial capacity of this planet's dominant hominids increased along a upward trendline, in starts and stops. Bipedal apes went from having nearly chimp sized crania to one similar to modern human beings (Neandertals had larger brains that H. sapiens sapiens). Symbolic culture as we know it though seems to really explode (a.k.a. "The Great Leap Forward") between 50,000 and 30,000 years ago. There have been many books on these issues. The Mating Mind, The Prehistory of the Mind and The Dawn of Human Culture hit many of the controversies…
razib | May 16, 2006John Hawks has the details on the rumors that have been swirling for a while (and now confirmed by a conference talk) about sequencing of autosomal Neandertal DNA. The previous work was mtDNA, which is easier since mitochondria are copious throughout the cell. But, this will give us a lot more information to chew on....
razib | May 16, 2006Don't have much time to comment, but I thought I'd point you to pending paper in PNAS (as usual, PNAS' webmaster is slow in getting this out though the press release says it is on their website) which suggests chimps have copy number variations similar to H. sapiens. The human genome is obviously interesting, but the recent focus on chimps too is obviously going to be important because to answer the question "what does it mean to be human?" it is good to have some perspective, and chimps are our nearest living relatives.
razib | May 15, 2006This week Seed is asking the question:
"Will the 'human' race be around in 100 years?"
Since I suggested the question, I have a quick set of answers. I believe there are three primary categories of alternatives:
1) The rate of technological (both bio & computational) change will continue to accelerate, and "humanity" as we know it will be transcended beyond comprehension.
2) Our complex technological society will collapse as our artifactual matrix overwhelms our cognitive substrate, and the sociological response will be like that of lemmings over a cliff. We will revert back to some…
razib | May 15, 2006In an update to my previous post, I point you to David B's post at my other blog where he expresses skepticism about the recent study that applied Hamiltonian principles to royal fratricide.
razib | May 14, 2006I welcome Jason Rosenhouse to SB. But, I take issue with the way he frames the issue of politics & evolution. He states:
People like Shapiro, George Will, or Charles Krauthammer are lonely voices in the conservative wilderness, accorded about as much respect in the Republican party as pro-lifers are in the Democratic party. Every conservative politican of any prominence is anti-Darwin, and virtually every right-wing media outlet publishes anti-evolution articles on a regular basis. Indeed, as Chris Mooney documented at book length, hostility towards science is an integral part of…
razib | May 14, 2006Seeing as this is Mother's Day, I want to point to this working paper, Menopause and post-generative longevity: Testing the 'stopping-early' and 'grandmother' hypotheses. It is a 44 page review of a lot of literature that is out there. The short of it is that menopause is something of a mystery, our nearest relatives, the chimps, seem to be rather normal animals in that the female reproductive lifespan is coterminus with the whole of her life after sexual maturation. In contrast, human females engage in a proactive "shut down" of reproductive capacity. Not only that, after menopause they…
razib | May 14, 2006Ed Brayton says:
To see an atheist taking a position that is usually held by those who claim to be Christian, typically southern nationalists, is quite disconcerting.
This is interesting. Here is what some might not know about: the racialist far Right tends to be populated by many individuals who have left Christianity. A substantial subset of these are atheists. Here is a quote from American Renaissance, the most highbrow of racialist publications, in regards to their subscriber base:
Two thirds of respondents believe in God, a figure lower than the national average of well over 90…
razib | May 13, 2006Discovery News has a fascinating review of new research which suggests that royal fratricide tended to follow Hamiltonian principles, that is, cousins were killed so that nearer relations could prosper. Hamilton's Rule states that an "altruistic" behavior is genetically beneficial if Cost < Benefit to Other X Coefficient of Relationship to Other (C < B*r). Roughly speaking, if you have a coefficient of relation to a siblling of 0.5, then for every unit of fitness you sacrifice for a sibling they need to increase their own fitness by over two units. The logic is simple: imagine you…
razib | May 12, 2006I'm reading Austin Burt & Robert Trivers' Genes in Conflict, and I'm in the chapter on genomic imprinting. They make a reference to a paper published a few years back which I vaguely remembered, by I decided to look it up again. Titled Paternally inherited HLA alleles are associated with women's choice of male odor, the authors found that women preferred the smell of men whose HLA alleles matched their paternally transmitted HLA alleles. Trivers & Burt point out that the actual HLA alleles the father actually had but did not transmit were not relevant, so that eliminates the…