Biology 100--Exam 3

Genetic change through time

Plants or animals with preferable traits are encouraged to reproduce--same as natural selection

-sailed to the galapagos islands and collected many plant and animal species to ultimately observe that there are many different species

Populations change (evolve) over time (generations) AND this change comes about by NATURAL SELECTION

Inherited trait that enhances an organism's ability to survive and reproduce in a particular environment

Micro is the change at the genetic level--population level (change in the gene pool over time) macro--change at the species level

Group of individuals of the same species living in the same place and at the same time

All of the alleles of all the genes in a population

-a change in the DNA -must be present in gametes if it is to contribute to the next generation-must affect chances for survival or reproduction

-All genotypes within a population are not equal-Some genotypes allow individuals to "better" survive and reproduce-Individuals with these genotypes are able to pass their genes on to the next generation

-A change in the gene pool due to chance events such as disasters

A severe reduction in a population

A few individuals from an existing population establish a new one

-everyone has a certain number of recessive alleles for genetic diseases in their genome-this is usually not a problem, as these alleles are very rare-problems can arise when inbreeding occurs

-a change in the gene pool due to immigration or emigration of individuals in and out of a population-tends to counter the effects of natural selection and genetic drift