Falush, Daniel Paul;
(1998)
The evolution of recombination rates caused by recurrent deleterious mutations.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
The exchange of genetic material through recombination underlies the evolutionary process. However, the factors which determine the evolution of the rate of exchange are poorly understood. In the thesis, I concentrate on the evolution of recombination rates caused by recurrent deleterious mutations. I have developed an approach to modelling recombination evolution which overcomes many of the limitations of previous methods. My main innovation is to make a simplifying assumption; I do not consider genes in linear arrays on chromosomes. Instead of treating genes as beads on a string, I treat them as beads in a pot. An important aspect of the variation in recombination is the variation between the sexes. For example, in humans, the female genetic map is 60% longer than the male genetic map. I use my genes-in-a-pot model to investigate the evolution of sex differences in recombination. I show that sex differences in recombination may evolve as a result of sex differences in the strength of selection. My results suggest that, in humans, the genetic map is longer in females because selection against deleterious mutations is stronger in males. Additionally, I show that, in mammals, male recombination rates should depend primarily on longevity while female recombination rates should show stronger dependence on sex differences in selection. The limited empirical data is consistent with the pattern I suggest. In the final chapters, I deal with some objections to my model of recombination evolution. A first objection is that an assuption of the model, synergistic interactions between mutations, is not biologically applicable. I show that synergism is likely to evolve in sexual species like mammals, which have high mutation rates. A second objection is that recombination is an incidental consequence of the crossing over mechanism which causes it. I show that selection on recombination is necessary to explain important features of crossover distribution.
Type: | Thesis (Doctoral) |
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Qualification: | Ph.D |
Title: | The evolution of recombination rates caused by recurrent deleterious mutations |
Open access status: | An open access version is available from UCL Discovery |
Language: | English |
Additional information: | Thesis digitised by ProQuest. |
Keywords: | Biological sciences; Recombination |
URI: | https://discovery.ucl.ac.uk/id/eprint/10101323 |
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