News tagged with genetic diversity

Related topics: genes , proceedings of the national academy of sciences , climate change , genetic variation , genome

One in four has alarmingly few intestinal bacteria

All people have trillions of bacteria living in their intestines. If you place them on a scale, they weigh around 1.5 kg. Previously, a major part of these 'blind passengers' were unknown, as they are difficult or impossible ...

Aug 28, 2013
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Genetic diversity

Genetic diversity is a level of biodiversity that refers to the total number of genetic characteristics in the genetic makeup of a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary.

The academic field of population genetics includes several hypotheses and theories regarding genetic diversity. The neutral theory of evolution proposes that diversity is the result of the accumulation of neutral substitutions. Diversifying selection is the hypothesis that two subpopulations of a species live in different environments that select for different alleles at a particular locus. This may occur, for instance, if a species has a large range relative to the mobility of individuals within it. Frequency-dependent selection is the hypothesis that as alleles become more common, they become less fit. This is often invoked in host-pathogen interactions, where a high frequency of a defensive allele among the host means that it is more likely that a pathogen will spread if it is able to overcome that allele.

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