Nucleotide level mutations
-mutations at a single or very few nucleotide level
-consist of point mutations and frameshift mutations
-point mutations: one nucleotide is substituted for another nucleotide
--silent mutations: have no affect on the protein. Most commonly occur on the t
inborn errors of metabolism
-defects in genes required for metabolism
-will cause the build up of metabolites in various pathways build up
-PKU mutation is an example.
-Can be dealt with if treated early on
leakage
-the flow of genes between species
-in some cases individuals from different species can produce hybrid offspring
-For example, Donkey and horse producing a mule
Genetic drift
-changes in the composition of the gene pool due to chance
-tend to be more pronounced in small populations
The founder effect
-a more extreme case of genetic drift in which a small population of species finds itself in reproductive isolation from other populations as a result of natural barriers.
-This and other bottlenecks that reduce the size of the population available for br
Chiasma
-the point of genetic recombination between two sister chromatids
Genetic map
-display of the different locations of the genes along a chromosome
-one map unit or centimorgan is equivalent to 1% chance of genetic recombination from occuring
natural selection and fitness
-natural selection is the theory that certain characteristics or traits possessed by individuals within a species that allow those individuals to have greater reproductive success
-Reproductive success is termed fitness
Modern synthesis model: neo-darwinism + differential reproduction
-adds knowledge of genetic inheritance and changes in the gene pool
-differential reproduction: when mutation or recombination results in a change that is favorable to the organisms reproductive success.
inclusive fitness
-a measure of an organism's success in the population based on the offspring, success in supporting offspring and the ability of the offspring to then support others.
puntuated equilibrium
-changes in some species occur in rapid bursts rather than evenly through time
stabilizing selection
-keeps phenotypes within a specific range by selecting against extremes
directional selection
-adaptive pressure can lead to the emergence and dominance of an initially extreme phenotype
disruptive selection
-two extreme phenotypes are selected over the norm
-facilitated by the existence of polymorphisms which are naturally occurring differences in form between members of the same population such as light and dark coloration in the same species of butterfly.
adaptive radiation
-the rapid rise of a number of different species from a common ancestors
-allows for various species to occupy different niches
-niche is a specific environment including habitat, available resources, and predators, for which a species is specifically ada
divergent evolution
-independent development of dissimilar characteristics in two or more lineages sharing a common ancestor
parallel evolution
-the process whereby related species evolve in similar ways for a long period of time in response to analogous environmental selection pressures
convergent evolution
-the independent development of similar characteristics in two or more lineages not sharing a recent common ancestor.