Evidence for Evolution Flashcards
homologus structures
similar structure and origin with different function
analogus structures
similar function but different origin
vestigial structure
structures from ancestors that are useless
biogeography
island populations
fossils
preserved remains or impressions that remain after a long period of time
embryology
similar stages of embryonic development
DNA
determines how closely organisms are related- by comparison, traits passed on by generations changed by mutations
divergent evolution
the same species can be isolated to different environments, limiting gene flow, to allow for the selection of different traits (homologus structures)
- two groups of the same species evolve different traits
convergent evolution
unrelated organisms that evolve similar traits due to similar environments or niches they inhabit (analogus structures)
parallel evolution
two related organisms, independently evolving on the same paths
What is evolution
change over time-process by which modern organisms descended from ancient ones
James hutton
forces change earth’s shape, changes are slow, earth is old
Charles Lyell
geographical features can be built up or torn down
Lamarck’s theory
tendency towards perfection (giraffe neck), use and disuse (birds using forearms), inheritance of acquired traits
Thomas malthus
if population grew=insufficient living space, food runs out (more babies born than die idea that Darwin applied to animals)
what do organisms with homologus structures have that organisms with analogus structures don’t have
a common ancestor
artificial selection
intentional breeding for certain traits-human preference could be a simulation for how it would play out
natural selection
process by which traits become more or less common in a population based on its importance to survival where the environment controls these factors
what are the five points of natural selection
populations has variations, some variations are favourable, more offspring are produced than survive, those that survive have favourable traits, a population will change over time
what is an adaptation
structure, behaviour, or physiological process that help an organism survive and reproduce in a particular environment
mimicry
the ability to mimic something you’re not; organisms mimicking another organism to appear like a more harmful species to have predators avoid it
what is a variation
structural, functional, or physiological differences between individuals of a species