darwin evolution

HMS Beagle

darwin’s ship

galapagos islands

islands isolated form the mainland where darwin analyzed creatures

origin of species by means of natural selection

name of darwins book

selective advantage

a genetic advantage of one organism over its competitors

reduces heat loss

purpose of round short ears for snow leopard

warms the air before it reaches the lungs

purpose of wide, short nasal cavity for snow leopard

seeing all the way around

purpose of high placed eyes for desert rabbits

selective pressures

external factors which affect an organisms ability to survive in a given environment

speciation

the formation of new species from existing species

divergent evolution

process in which the descendants of a single ancestor diversify into species that each fit different parts of the environment

convergent evolution

process by which different species evolve similar traits

coevolution

when 2 or more species have evolved adaptations to each other’s influence (e.g. bees and flowers)

artificial selection

when humans decide which trait will dominate

extinction

likely result of monoculture and lack of diversity

geographic isolation/allopatric speciation

population may become separated when their habitat becomes physically separated

reproductive isolation/sympatric speciation

results from barriers to successful breeding between population groups in the same area

gradualism

the idea that peciation occurs at a regular, gradual, rate taking thousands of years

punctuated equillibrium

a theory stating that speciation happens in bursts and there are long periods of no change, no gradual change and organisms changed overnight

extinction

the end of a species due to a lack of survival traits

bartesian mimicry

model organism is dangerous while the mimic is not

mullerian mimicry

both model and mimic and dangerous and have evolved to look like each other

self mimicry

species fools its prey by looking inviting or familiar