Download presentation
Presentation is loading. Please wait.
1
Genetics The rate of evolutionary change in a population is proportional to the amount of genetic diversity available.
2
Genetic variation has three levels: heterozygosity- genetic variation within individuals variation among individuals within a population variation among populations
3
Results of the loss of genetic diversity: lower fitness- i.e. lifetime reproductive success relative to other individuals in the population reduced evolutionary flexibility of populations
4
Causes of declines in genetic diversity: Founder effect- when a few individuals establish a new population, the genetic composition depends on the founders Demographic bottlenecks- occurs when a new population experiences a severe, temporary reduction of size Genetic drift- random change in gene frequencies in small populations. Through chance alone some alleles will not be represented in the next generation.
5
Genetic Diversity: Inbreeding inbreeding- mating with closely related individuals results: increased homozygosity inbreeding depression- reduced fecundity, offspring size, growth, or survivorship; changes in age of maturation and physical deformities
6
Loss of among-population genetic diversity: when historically divergent, isolated populations experience unusually high rates of gene flow… organisms are moved creation of new corridors
7
Management Concerns maintenance of viable populations in the short term maintenance of the ability to adapt maintenance of the ability for continued “natural” speciation
8
Populations deme- locally, randomly interbreeding group of individuals metapopulation- network of populations that have some degree of intermittent or regular gene flow among geographically distinct units. populations exist along a continuum
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.