Please enable JavaScript.
Coggle requires JavaScript to display documents.
population genetics and evolution - Coggle Diagram
population genetics and evolution
population genetics
population genetics
deals with the abundance of different alleles within a population and the manner in which the abundance of a particular allele increases, decreases, or stays the same
gene pool - total number of alleles in all of the sex cells of all the individuals in a population
factors that cause the gene pool to change
mutation
accidents
rates of evolution
very slow
difficult to distinguish unless the phenotype is changed
speciation
speciation- when natural selection has cause a species to evolve, forming a new species.
phyletic speciation - one species gradually becomes so changed that it must be considered a new species
divergent speciation - some populations of species evolve into new, second species while other populations either continue or evolve into new, third species.
gene flow - movement of alleles physically through space
abiological reproductive barrier -any physical non-living feature that prevents 2 populations from exchanging genes
biological reproductive barrier - any biological phenomenon that prevents successful gene flow.
sympatric speciation - when 2 groups become reproductively isolated even though they grow together
adaptive radiation - special case of divergent evolution in which a species rapidly diverges into many new species over an extremely short time
evolution and the origin of life
chemosynthesis - hypothesis on the origin of life that uses only known chemical and physical processes
earth condensed from gases and dust 4.6 bya was hot and rocky and had an atmosphere composed mostly of hydrogen
Earths first atmosphere was replaced by a second atmosphere that was produced from releasing gases from the rock matrix and a heavy bombardment of meteorites.
the second atmosphere was a reducing atmosphere due to the lack of molecular oxygen
artificial selection
artificial selection - the process in which humans purposefully change the allele frequency of a gene pool
selective breeding
used for ornamental plants
carried in conjunction with artificial mutation
natural selection
natural selection - those individuals most adapted to an environment will survive. (survival of the fittest)
2 conditions must be met before natural selection occurs:
The population must produce more offspring than can possibly grow and survive to maturity in that habitat.
progeny must differ from eachother in their types of alleles