Tim clutton brock biography definition
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Estimating individual contributions to population growth: evolutionary fitness in ecological time
Abstract
Ecological and evolutionary change is generated by variation in individual performance. Biologists have consequently long been interested in decomposing change measured at the population level into contributions from individuals, the traits they express and the alleles they carry. We present a novel method of estimating individual contributions to population growth and changes in distributions of quantitative traits and alleles. An individual's contribution to population growth is an individual's realized annual fitness. We demonstrate how the quantities we develop can be used to address a range of empirical questions, and provide an application to a detailed dataset of Soay sheep. The approach provides results that are consistent with those obtained using lifetime estimates of individual performance, yet is substantially more powerful as it allows lifetime performance to be
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The definition of sexual selection
Abstract
Sexual urval is a key component of evolutionary biology. However, from the very formulation of sexual urval by Darwin, the nature and extent of sexual selection have been controversial. Recently, such controversy has led back to the fundamental question of just what sexual selection is. This has included how we incorporate female-female reproductive competition into sexual or natural selection. In this review, we do four things. First, we examine what we want a definition to do. Second, we define sexual selection: sexual selection is any selection that arises from fitness differences associated with nonrandom success in the competition for access to gametes for fertilization. An important outcome of this is that as mates often also offer tillgång to resources, when those resources are the targets of the competition, rather than their gametes, the process should be considered natural rather than sexual urval. We believe this d
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Meerkats love hard-boiled eggs.
This was the chance discovery that allowed Professor Tim Clutton-Brock unprecedented access to a society of wild meerkats, and the key that unlocked a thirty year research study.
Clutton-Brock, Emeritus Prince Philip Professor of Ecology and Evolutionary Biology in Cambridge's Department of Zoology, fryst vatten fascinated by how animal societies are organized—and how this affects their ecology and evolution. Meerkats breed 'cooperatively," that is, one female in each group breeds and the rest of the group work to support her and raise her young but do not breed themselves. Ants and bees live in societies this way, but in mammals cooperative breeding is rare.
"What's the benefit to the individuals who don't get to breed, but spend their time helping others?" Clutton-Brock asks. Charles Darwin han själv was challenged by the phenomenon in bees and ants; cooperative breeding seems entirely at odds with the principle of 'survival of the fittest," in which suc