What does bottleneck mean in science

Love words? Need even more definitions? Homophones, Homographs, and Homonyms The same, but different. Merriam-Webster's Words of the Week - Nov. Ask the Editors 'Everyday' vs. What Is 'Semantic Bleaching'? How 'literally' can mean "figuratively". Literally How to use a word that literally drives some pe Is Singular 'They' a Better Choice? The awkward case of 'his or her'. Following a population bottleneck, the remaining population faces a higher level of genetic drift, which describes random fluctuations in the presence of alleles in a population.

In small populations, infrequently occurring alleles face a greater chance of being lost, which can further decrease the gene pool. Due to the loss of genetic variation, the new population can become genetically distinct from the original population, which has led to the hypothesis that population bottlenecks can lead to the evolution of new species.

Further Exploration Concept Links for further exploration allele allele frequency gene genetic drift Hardy-Weinberg equilibrium evolution. UC Berkeley. This is illustrated by the bags of marbles shown below, where, in generation 2, an unusually small draw creates a bottleneck.

Reduced genetic variation means that the population may not be able to adapt to new selection pressures, such as climatic change or a shift in available resources, because the genetic variation that selection would act on may have already drifted out of the population. Northern elephant seals have reduced genetic variation probably because of a population bottleneck humans inflicted on them in the s.

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