razib | February 15, 2007Yesterday I posted about the mtDNA results which suggest that Etruscans were Anatolian emigres to Italy. More data just came to light:
In the region corresponding to ancient Etruria (Tuscany, Central Italy), several Bos taurus breeds have been reared since historical times. These breeds have a strikingly high level of mtDNA variation, which is found neither in the rest of Italy nor in Europe. The Tuscan bovines are genetically closer to Near Eastern than to European gene pools and this Eastern genetic signature is paralleled in modern human populations from Tuscany, which are genetically…
razib | February 14, 2007Most of you know that I believe there are serious problems with much of contemporary historical population genetics. Grand unfounded narratives, and scientists who lack requisite historical knowledge, litter the field. But, narrow, precise and crystal clear studies do emerge now and then. This is a case in point, Mitochondrial DNA Variation of Modern Tuscans Supports the Near Eastern Origin of Etruscans:
Interpopulation comparisons reveal that the modern population of Murlo, a small town of Etruscan origin, is characterized by an unusually high frequency (17.5%) of Near Eastern mtDNA…
razib | February 13, 2007Had to link to a paper with such a title. Relative Impact of Nucleotide and Copy Number Variation on Gene Expression Phenotypes:
...SNPs and CNVs captured 83.6% and 17.7% of the total detected genetic variation in gene expression, respectively, but the signals from the two types of variation had little overlap....
Here's a quote from a popular press article:
"We've been able to look back into our history and find changes that are older and likely to be shared among populations," explained Dr Manolis Dermitzakis, senior author and Project Leader at the Wellcome Trust Sanger Institute. "But we…
razib | February 13, 2007My coblogger @ GNXP Ikwa has a measured response to Chris Mooney and Alan Soka's notable op-ed about the conflict between the Right & science. Here's the gist:
For example, I don't think it's obvious that fundamentalist Christian fears that Darwinism will lead to the death of morality and the collapse of civil society are less reasonable or strongly-believed than the fear that the discovery of a genetic or biological contribution to social inequalities will lead to death of empathy for the disadvantaged and the collapse of all progressive values. Parenthetically, I don't think either…
razib | February 12, 2007When I was in 7th grade a school psychologist tested & interviewed me for the gifted program. During the knowledge section he asked me to describe Charles Darwin's theory of evolution. I am pretty sure that my response was rather garbled, I don't personally think I really understood evolution until late in 2003, nevertheless, after repeating the standard mantra of change over time generated by the process of survival of the fittest the psychologist paused and smiled at me. He stated that "That's the first time ever that any student has responded to that question in a coherent manner…
razib | February 12, 2007A Week of Just Science just finished up, and to all those who participated, I say bravo! The stipulation to post only science and at least one item of meaty substance per day was straining for many of us, and life intervenes and not everyone could hit their quota. But that's fine, the point wasn't to hit some magical number or achieve a quantitative threshhold of posts. Rather, we wanted to ask what we asked and see how people responded, and I was personally rather pleased.
The Just Science website will be "frozen" for the next year, until next February when the aggregator will fire up…
razib | February 11, 2007Update: Greg Laden has a post worth reading on tis topic.
Sexual selection is an expansive topic. It is also one with a complicated history and fits messily into a rigorous empirical research program. I will base this post predominantly on the verbal exposition in R.A. Fisher's The Genetical Theory of Natural Selection. My reason is simple: though progress in formalization of sexual selection theory has been significant within the past 25 years, the major issues and concepts were sketched out by Fisher.
Prior to Fisher sexual selection was discussed quite extensively by Charles Darwin, but…
razib | February 10, 2007Many months ago I was reviewing R.A. Fisher's The Genetical Theory of Natural Selection when I touched upon his view of the nature of adaptation, precisely, that it occurs though the substitution of mutations of small effect. This dovetails with the "gradualism" which Charles Darwin promoted, and is also the thinking that drive's Richard Dawkins conception of evolution promoted in his popular books. In contrast, in the contemporary age S.J. Gould was most closely associated with the position that mutations and evolutionary changes of a larger scale, macromutations, may play a role in…
razib | February 10, 2007I hope you've been checking out the Just Science site this week. If you haven't, I recommend the RSS feed, http://www.justscience.net/?feed=rss2 for ease of browsing. In any case, I just want to announce that I'm shutting down the feeds Sunday night at 9 PM PDT. The site will then be frozen in that form until next year, when we'll do this again. Thanks to everyone who participated, and I hope you've been enjoying the posts. If you haven't had time to check everything out, you know where to go for the next year to browse them. Below the fold I've placed the URLs for all the participating…
razib | February 9, 2007The "domestic" cat, Felis silvestris catus, has been with us for nearly 10,000 years. Recently, a 9,500 year old burial of a human and their companion cat was discovered on Cyprus. Cats are not indigenous to the island, so it seems that the presence of this cat must be owed to human intervention in some manner. Though we are used to thinking about how humans shaped cats through selective breeding the recent data on Toxoplasma gondii suggests that cats might have an impact on human behavior that could explain cultural differences! Some intellectuals have posited that the selection of…
razib | February 8, 2007I've always had an interest in human origins, and have been an avid consumer of books and papers relating to the emergence of our own species through an evolutionary lens. Though I am interested in paleontology, my own bias has been to look toward the genetic evidence because it is more accessible (that is, paleontology focused on morphological characters presupposes a knowledge of anatomy and general familiarity with osteology which I lack). Because of my age some of the works which I stumbled upon were from the 1970s, during which a debate had erupted between Allen Wilson, who argued for a…
razib | February 7, 2007Why do humans cooperate? Why do we behave "altruistically"? These are the sort of "big" questions which the human sciences explore. From the vantage point of evolutionary biology there has been a long history of exploring, and attempting to explain, altruistic behavior. And yet such questions weren't always considered of great value, the great W.D. Hamilton was discouraged from his exploration of this topic by his department head. At one point he took up carpentry to furnish for himself an income while he pursued his science in his spare time, so pessimistic was he about receiving academic…
razib | February 6, 2007The idea of stochastic training wheels sounds a bit scary, but I am alluding to the series of posts on stochastic dynamics adapted from chapter 5 of Evolutionary Genetics: Concepts & Case Studies by John Gillespie. Using Gillespie's terminology the posts were:
Boundary Process
Origination Process
Genetic Drift
Genetic Draft
Random Environment
There was also another factor which Gillespie points to, which didn't have a particular section and rather loomed over all the other parameters, and that was Deterministic Selection.
Of Gillespie's parameters only one is highly dependent on the…
razib | February 5, 2007The conventional Mendelian
model for diploid organisms assumes that the expression of an autosomal
allele within an individual should be invariant of its sex of origin,
that is, whether it is inherited from the father or the mother.
This model is incorrect for a subset of alleles across many taxa, in
particular mammals. In 1989 David Haig and Mark Westoby outlined
the evolutionary rationale for parent specific gene expression.1
In 1992 paternal and maternal specific imprinting of the insulin growth
factor 2 and insulin growth factor 2 repressor loci (Igf2,
Igf2r) in mice confirmed their…
razib | February 4, 2007A Week of Science starts tomorrow. I've loaded up an aggregator blog at http://www.justscience.net, but the best place to follow things will be via RSS, http://www.justscience.net/?feed=rss2.
razib | February 1, 2007I've been sick. Flu. That's why I haven't been posting. I will be posting again soon. But I am taking time out to post something right now, because having a blog means having a place to vent.
1) 2.5 weeks ago I ordered a piece of hardware from amazon
2) The hardware did not work
3) I called amazon, they said they'd replace it immediately
4) The replacement did not arrive
5) I called, and they explained (Amazon) that the item was now on backorder
6) When I had my item replaced they assured me that the item was not on back order
7) OK, so I told them to give me a refund, I needed the hardware…
razib | January 27, 2007Pretty cool. Via Afarensis.
I am:
Arthur C. Clarke
Well known for nonfiction science writing and for early promotion of the effort toward space travel, his fiction was often grand and visionary.
Which science fiction writer are you?