razib | November 16, 2006From here: "Cronin et al. (1991) then discovered that mtDNA of brown bears is paraphyletic with respect to polar bears. That is, the mtDNA of brown bears of the Alexander Archipelago in southeastern Alaska is more closely related to the mtDNA of polar bears than it is to the mtDNA of other brown bears. Cronin et al. (1991) reported that mtDNA sequence divergence between Alexander Archipelago brown bears and polar bears is only about 1%, whereas a divergence of about 2.6% separates polar bears from brown bears occurring elsewhere...Following the discovery of Cronin et al. (1991), others…
razib | November 16, 2006More Neandertal news, as promised!
John Hawks is getting so much traffic that his site is getting bogged down. Anyway, he posts on the two studies that came out on Neandertal genomic sequencing. No big news, Neandertals are very different, and there isn't a great deal of evidence for mixing resulting in a large load of Neandertal derived genes in modern populations. RPM has more. At my other blog p-ter excises an important point:
[T]his high level of derived alleles in the Neanderthal is incompatible with the simple population split model estimated in the previous section, given split times…
razib | November 15, 2006This comment made me aware that I should probably be more precise about how I view the "new model," which I will provisionally label "Ecotype Persistence" (EP), as being different from Multi-regionalism in the old school. Consider two variables:
Full genome content
Phenotypically salient characters (controlled by a few selected loci)
Full genome content is the whole shebang, and it can be thought of as a proxy for ancestry. Phenotypically salient characters on the other hand are simply a reflection of adaptation's power in a local time and space, sans phylogenetic constraint they can be…
razib | November 15, 2006
The Out of Africa Replacement Model
The Multi-regional Model
The Introgression Model?
I have a question mark in the last case because this idea that we can have a simple to illustrate and verbally elegant "model" that we promulgate across the land might have to go. Parsimony to the back of the class...for now. John already chided me for presenting the old introgression via hybrid zone model as if it was the last word. I think it is important to not place evolutionary dynamics into a demographic box, the history of genes are reticulated, and do not respect our simple narratives.…
razib | November 15, 2006The Lord Our God is One! Check out my results from the Belief-O-Matic below....
1. Unitarian Universalism (100%)
2. Secular Humanism (98%)
3. Mainline to Liberal Christian Protestants (88%)
4. Liberal Quakers (84%)
5. Nontheist (75%)
6. Theravada Buddhism (68%)
7. Bah�'� Faith (65%)
8. Neo-Pagan (65%)
9. Christian Science (Church of Christ, Scientist) (58%)
10. Church of Jesus Christ of Latter-Day Saints (Mormons) (58%)
11. Reform Judaism (50%)
12. New Age (45%)
13. Taoism (45%)
14. New Thought (45%)
15. Mainline to Conservative Christian/Protestant (43%)
16. Sikhism (40%)
17.…
razib | November 15, 2006My next post on Gillespie's chapter in Evolutionary Genetics: Concepts & Case Studies is going to cover "genetic draft." I don't know when I'll get to it, so I'll point to Robert Skipper's post on the topic from six months ago. Yes, selection is proximately stochastic. Like this.
razib | November 15, 2006I have spoken of the probability of extinction and the rate of substitution once past extinction, but now to something more prosaic, genetic drift. My post is based on John Gillespie's treatment in Evolutionary Genetics: Concepts & Case Studies. Like R.A. Fisher he does not think much of this process in evolutionary dynamics, and deemphasizes its salience. The easiest way to think of drift is simply as sample variance over generations, the expected deviation from the mean as one moves through time. In a diallelic model the deviation between generation n and generation n + 1 is:
σ…
razib | November 14, 2006Over at my other weblog there is a post up, Genomics and socialized health care, which asks if the new DNA era might not explode the acturial edifice that is modern health insurance in the United States. I suspect in this case many will welcome a "broken" system which needs to be replaced by a universal single-payer system, at least on the basal level. But, with privilege comes responsibilities. I suspect that the overturning the old system of health insurance, which was predicated on imperfect knowledge, will be correlated with the rise of a new system where particular values common…
razib | November 14, 2006Question:
What are the best pickup lines for scientists and science-savvy folk?...
I'll go narrow-church: low mutational load baby, look beyond the proximate and focus on the ultimate.
razib | November 14, 2006It seems that The Family That Walks on All Fours is now on NOVA. I don't have a television so I won't be seeing it, but some of you might catch a re-run. Years ago I remember a slogan: "If PBS doesn't do it, who will?" Hm.
razib | November 14, 2006Ancient Crash, Epic Wave is a story in The New York Times about an enormous impact 4,800 years which might have had world-wide repercussions:
At the southern end of Madagascar lie four enormous wedge-shaped sediment deposits, called chevrons, that are composed of material from the ocean floor. Each covers twice the area of Manhattan with sediment as deep as the Chrysler Building is high.
...
The explanation is obvious to some scientists. A large asteroid or comet, the kind that could kill a quarter of the world's population, smashed into the Indian Ocean 4,800 years ago, producing a tsunami…
razib | November 14, 2006This is more for google, but if you missed anything, you should check it out. Here is a replay of the introgression & Neandertal related posts....
Preview:
Neandertal & H. sapiens sapiens interbreeding
Neandertal-"modern" mixing
Introgression related posts over the past 6 months
Main course:
Did Modern Humans Get a Brain Gene from Neandertals? (link to Lahn. et. al.)
Neandertal & humans - introgression (this has the nice graphic that people seem to think illustrates the concept pretty well)
The Neandertal child (a face to it all)
Introgression vs. gene flow (illustration of…
razib | November 13, 2006Scientific American has a nice link round up on l'affaire Lahn & Neandertals.
razib | November 13, 2006PLOS Biology and PLOS Genetics have a slick brand new look. Go check 'em out!
razib | November 13, 2006Aziz points me to this article over at alt.muslim which reviews Murder in Amsterdam by Ian Buruma. It is a fair review, but this caught my attention:
...Buruma's parallelisation of the careers of both Fortuyn and Van Gogh and their capitalisation on Islamophobia begs the question of how the Enlightenment virtues of freedom and reason could have been politically perverted to justify hatred for a racial underclass. This crucial question, posed repeatedly, if not directly, by Buruma through his coinage of the term "Enlightenment fundamentalist" represents the most intellectually fascinating…
razib | November 11, 2006John Hawks has a long post on introgression in the context of the Species Concept problem.
razib | November 11, 2006The Inductivist cranked the GSS to figure which American ethnic groups are spiritual and which are not, and this is what he found:
SpiritualityEthnic Group
1.92East Asians
2.78Scandanavians
2.8Italians
2.9Irish
2.9Germans
2.91Mexicans
2.95English/Welsh
3.12American Indians
3.26Blacks
3.29Scots
razib | November 10, 2006It's been a bit rainy in the Northwest, Kevin Vranes has some commentary. There is a joke that one reason that the Pacific Northwest is so unchurched is that God is all around us nature. Usually we are taking about majestic vistas, but sometimes it is also about the fury of the Lord.