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9

Fisher's principle applies to such cases as much as it does to species where only pairs mate. Consider a species where a successful male has exclusive mating with a harem of 20 females, and for each such male, 19 other males are not able to mate. A female has 100% chance of mating, and a male has a 5% (1 in 20) chance of mating. Assume a female has two ...


7

I need to point out one thing, natural selection does not bring species to perfection. The best mutant may not be selected for many reasons. When you have no selection pressure then you have neutral evolution concurring and what takes over instead of natural selection is genetic drift. Genetic drift is just sample error. Say you have 1,000 individuals in ...


5

A commonly used empirical example of species selection (a.k.a clade selection, lineage selection) is pelagic larvae in sessile ocean species. See Maliska et al (2013) for a recent paper discussing this in Tunicata and Jablonski & Hunt (2006) for larval modes in gastropods. The idea is to some extent really intuitive - pelagic larvae means higher ...


4

This is called the "Thrifty Gene Hypothesis" which was first used to explain why diabetes is so common. Basically it suggests that these alleles would have provided some kind of advantage, over the other possible alleles at that loci, until the environment changed. Then the environment changed and the allele became harmful. Environments are always changing ...


3

Joan Strassman's work is probably the route to go for this. The short of your answer is that several things mediate who ends up where in the slug: Cheaters are limited from exploiting other clones by high relatedness, kin discrimination, pleiotropy, noble resistance, and lottery-like role assignment. Here's the most relevant paper: Strassmann, J. ...


2

Even if a species lives in abundance, there is still an evolutionary arms race: who reproduces the fastest? Even slight advantages in reproduction rate multiply over the generations. There are, however, cases where selection pressures on specific traits have vanished. For example, for fish living in caves, there is not selection pressure to be able to see, ...


2

mgkrebbs has already covered the maths that leads to the preservation of ratio, so I'll not recap. You might have noticed that the argument only remains true if you don't know whether the particular male you produce is likely to be the dominant male or not. If you could "know" in advance that your particular son was more likely to be dominant it would make ...


2

I don't have access to Provine's book, and I can't describe the details of the hooded rat experiments, but here is an attempt to explain the importance of the work. Darwin published “Origin of Species” in 1859. He proposed that modern species were all descended from ancestral species, and that evolution proceeded by natural selection. He believed that ...


1

If I understand you correctly, I've seen this idea in many papers, sometimes stated clearly and sometimes in more implicit terms. After a quick look I found a paper which should be relevant as a starting point for you: Mayor et al. 2007. Spectrum of selection: new approaches to detecting the scale-dependent response to habitat. Ecology 88(7). In my mind, ...


1

I think there might be several places to read a description of these experiments, but they are discussed extensively in a book by historian-philosopher Lindley Darden, entitled "Theory Change in Science: Strategies from Mendelian Genetics", parts of which are available online. See p. 112 of Darden's book for references to other accounts of these experiments ...



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