Category: Select Post
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You are a mutant!
The Pith: You are expected to have 30 new mutations which differentiate you from your parents. But, there is wiggle room around this number, and you may have more or less. This number may vary across siblings, and explain differences across siblings. …
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Your genes, your rights – FDA’s Jeffrey Shuren misleading testimony under oath
Over the past few days I’ve been very disturbed…and angry. The reason is that I’ve been reading Misha Angrist and Dr. Daniel MacArthur. First, watch this video: In the very near future you may be forced to go through a “profess…
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Sweeping through a fly’s genome
Credit: Karl Magnacca The Pith: In this post I review some findings of patterns of natural selection within the Drosophila fruit fly genome. I relate them to very similar findings, though in the opposite direction, in human genomics. Different forms o…
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The genomic heritage of French Canadians
Image Credit: Anirudh Koul One of the great things about the mass personal genomic revolution is that it allows people to have direct access to their own information. This is important for the more than 90% of the human population which has sketchy ge…
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The paradigm is dead, long live the paradigm!
Mitochondrial DNA and human evolution: Mitochondrial DNA from 147 people, drawn from five geographic populations have been analysed by restriction mapping. All these mitochondrial DMAs stem from one woman who is postulated to have lived ab7out 200,000 years ago, probably in Africa. All the populations examined except the African population have multiple origins, implying that…
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Homozygosity runs in the family (or not)
The number 1 gets a lot more press than -1, and the concept of heterozygosity gets more attention than homozygosity. Concretely the difference between the latter two is rather straightforward. In diploid organisms the genes come in duplicates. If the alleles are the same, then they’re homozygous. If they’re different, then they’re heterozygous. Sex chromosomes…
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What intra- & inter- population genetic variance tells us
The figure to the left is a composite merged from two different papers. One analyzes the patterns of genetic variation within African Americans, and the other the patterns within the East Turkic ethnic group, the Uyghurs. The bar plots show the ancestral element which is similar to two parent populations which resemble Europeans and Africans…
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Sex with thee and the last woman
A quintessentially sexy topic in biology is the origin of sex. Not only are biologists interested in it, but so is the public. Of Matt Ridley’s older books it is predictable that The Red Queen has the highest rank on Amazon. We humans have a fixation on sex, both in our public norms and our…
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The adaptive space of complexity
Evolution means many things to many people. On the one hand some scholars focus on time scales of “billions and billions,” and can ruminate upon the radical variation in body plans across the tree of life. Others put the spotlight on the change in gene frequencies on the scale of years, of Ph.D. programs. While…
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To gain pallor is easier than losing it
John Hawks illustrates what can be gained at the intersection of old data and analysis and new knowledge, Quote: Boyd on New World pigmentation clines: I’m using some statistics out of William Boyd’s 1956 printing of Genetics and the Races of Man[1]. It gives a good accounting of blood group data known more than fifty…
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The city that kills you makes you strong!
Over the past day I’ve seen reports in the media of a new paper which claims that long-term urbanization in a region is strongly correlated with genetic variants for disease resistance. I managed to find the paper on Evolution’s website as an accepted manuscript, ANCIENT URBANISATION PREDICTS GENETIC RESISTANCE TO TUBERCULOSIS: A link between urban…
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Simple rules for inclusive fitness
With the recent huge furor over the utility of kin selection I’ve been keeping a closer eye on the literature on inclusive fitness. The reason W. D. Hamilton’s original papers in The Journal of Theoretical Biology are highly cited is not some conspiracy, rather, they’re a powerful framework in which one can understand the evolution…
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Of Iran, Turan, and Turks
There’s a new paper out in The European Journal of Human Genetics which is of great interest because it surveys the genetic and linguistic affinities of two dozen ethno-linguistic groups from the three Central Asian nations of Uzbekistan, Kyrgyzstan, and Tajikistan. This is what the Greeks referred to as Transoxiana, and the Persians as […]
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A fly’s life: adventures in experimental evolution
Natural selection happens. It was hypothesized in copious detail by Charles Darwin, and has been confirmed in the laboratory, through observation, and also by inference via the methods of modern genomics. But science is more than broad brushes. We need to drill-down to a more fine-grained level to understand the dynamics with precision and detail,…
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Sexual selection: lowered expectations edition
Sexual selection is, for lack of a better term, a sexy concept. Charles Darwin elaborated on the specific phenomenon of sexual selection in The Descent of Man, and Selection in Relation to Sex. In The Third Chimpanzee Jared Diamond endorsed Darwin’s thesis that sexual selection could explain the origin of human races, as each isolated…