evolution and speciation

– the ability of an organism to pass on its alleles

– differential reproduction of an organism based upon fitness in its environment-the alleles that confer fitness will increase in frequency in the gene pool over time

– Selection against the extremes (for the averages)

– Selection against the averages (for the extremes)

– Selection against one extreme (but favoring the opposite extreme)

– directional selection done by humans with selecting for traits in animals and crops

– Differential mating between males and females

– group of organisms that are capable of interbreeding to produce ‘fit’ offspring

– barriers preventing members of different species from producing ‘fit’ offspring

– the existence of multiple phenotypes within a population

an inherited trait that confers greater fitness

– an adaptation to a specific function or environment

• – the sum of the environmental requirements required for a species to persist
• -includes habitat, predators, prey, etc.; thought of as being unique for each species

– increased likelihood of mating between organisms with similar genotypes (limits genetic variation)

- increased likelihood of mating between organisms with different genotypes

• – random change in allele frequencies in a population
• -smaller populations are more susceptible to genetic drift

– dramatic decrease in size of a population making it susceptible to genetic drift

– two species possess the same analogous structures unrelated to a common ancestor

– divergence leading to distinct populations / species

– similar evolutionary changes in different species due to similar environmental pressures

• 1) Parasitism
• 2) Commensalism
• 3) Mutualism

– when a species requires another species as a host to live, harming the host in the process

– an organism requires another species as a host to live with no harm or benefit to the host

– symbiotic relationship between two organisms that confers fitness to both

– Similarities in stages of development (ontogeny) can be used to determine evolutionary relationships between organisms.