Evolution in higher dimensions
Ornithomimosaurian dinosaur & ostrich, image credit Nobu Tamura & James G. Howes
The Pith: This post explores evolution at two different scales: the broad philosophical and the close in genetic. Philosophically, is evolution a highly conti…
Evolution may explain why baby comes early
Image credit
The Pith: In this post I review a paper which covers the evolutionary dimension of human childbirth. Specifically, the traits and tendencies peculiar to our species, the genes which may underpin those traits and tendencies, and how that …
The flat and the fit
The Pith: In evolution if you want to win in the long run you don’t want all your eggs in one basket, even if that’s the choicest basket. Sh*t happens, and you better have some back up strategies.
Diversity is a major question in evolution…
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…
The evolution of man is no cartoon
I was semi-offline for much of last week, so I only randomly heard from someone about the “Science paper” on which Molly Przeworski is an author. Finally having a chance to read it front to back it seems rather a complement to other papers…
Evolutionary Genetics
Short comment: Enough mathematical formalism to be technically illuminating, but not so much as to be opaque to the non-specialist.
Evolutionary Genetics
Short comment: Enough mathematical formalism to be technically illuminating, but not so much as to be opaque to the non-specialist.
More bad mutations = greater fitness
Does the chart above strike you as strange? What it shows is that the mean fitness of a population drops as you increase the rate of deleterious mutation (many more mutations are deleterious than favorable)…but at some point the fitness of the population bounces back, despite (or perhaps because of?) the deleterious mutations! This would […]
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 […]
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 […]
Story of X
A month ago I pointed to a short communication in Nature Genetics which highlighted differences in the patterns of variation between the X chromosome and the autosome. I thought it would be of interest to revisit this, because it’s a relatively short piece with precise and crisp results which we can ruminate upon.
Sometimes there is […]
Raging against the population genetics machine
An interesting readable review in PLoS Genetics taking on population genetics, Frail Hypotheses in Evolutionary Biology:
In conclusion, I return to Michael Lynch’s challenging questions about blind spots and bad wheels in evolutionary biology which motivated this review…Concerning blind spots I have pointed out some limitations of current population genetics. There is too much emphasis on […]
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, […]
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 […]
Not the origin of genome complexity
Over the past decade evolutionary geneticist Mike Lynch has been articulating a model of genome complexity which relies on stochastic factors as the primary motive force by which genome size increases. The argument is articulated in a 2003 paper, and further elaborated in his book The Origins of Genome Architecture. There are several moving parts […]
A thousand little adaptive platoons
Last week I took an intellectual road trip back nearly a century and explored the historical context and scientific logic by which R. A. Fisher definitively fused Mendelian genetics with quantitative evolutionary biology. In the process he helped birth the field of population genetics. While the genetics which we today are more familiar with begins at […]
Genetics is One: Mendelism and quantitative traits
In the early 20th century there was a rather strange (in hindsight) debate between two groups of biological scientists attempting to understand the basis of inheritance and its relationship to evolutionary processes. The two factions were the biometricians and Mendelians. As indicated by their appellation the Mendelians were partisans of the model of inheritance formulated […]