BLG 181 Lecture Notes - Lecture 17: Lead Poisoning, Genetic Recombination, Extinction Vortex
10 Jan 2017
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Document Summary
Low genetic variability low fitness low adaptability. Extinction vortex: small population inbreeding & genetic drift loss of genetic variability . Inbreeding depression reduced fitness higher mortality extinction. Case study: peregrine falcon: ddt (cid:272)ause the fal(cid:272)o(cid:374)s" eggs to (cid:271)e super thi(cid:374) a(cid:374)d fragile, saved by captive propagation and release. Case study: white rhino: overhunting pushed white rhinos to the edge of extinction, operation rhino transported rhinos from surplus areas to protected areas to breed. Outbreeding enhancement: breeding together different populations of the same species (subspecies) to increase heterozygosity, as they share fewer harmful recessive traits: cons: also results in potential for less well adapted offspring. Case study: black rhino: low genetic variation because of low numbers prompted relocation of some rhinos to protected areas, offspring were not as well adapted to environment. Case study: california condor: brink of extinction due to lead poisoning, captive propagation helped bring numbers up. Bottom trawling: cheap, but hits lots of non-target species huge bycatch.
