Artifical selection & Bottlenecks
In biology class we are learning about the forces of evolution.The six main forces of evolution are artifical selection,bottelnecks,founder effects,gene flow,gene drift,and natural selection.
Artifical selection- Farmers and breeders allowed only the plants and animals with desirable characteristics to reproduce,causing the evloution of farm stock.This process is called artifical selection because people(instead of nature) select which organisms get to reproduce.
Bottlenecks- Population bottlenecks occur when a population's size is reduced for at least one generation.
Founder effects & Gene flow
Founder effects- A founder effects occurs when a new colony is started by a few members from the original population.This small population size means that the colony may have: reduced gentic variation from the original population and a non-random sample of the genes in the original population.
Gene flow- Gene flow(also called migration) is any movement of individuals,and/or the genetic material they carry,from one population to another.
Genetic drift & Natural selection
Genetic drift- In each generation,some individuals,just by chance,leave behind few more descendents (and genes,of course) than other individuals.The genes of the next generation will be of the "lucky" individuals,not necessarily the healthier or the "better" individuals.That,in a nutshell,is gentic drift.
Natural selection- There is varation in traits,differential reproduction,and heredity.