the slow, gradual change in a species is called
evolution
what is biodiversity
variety of living organisms in an area
what are homologous structures
structures that look the same but different functions, EX. forelimbs of diffrent species have radius, ulna, but fuction diffrently
what was lamarcks theory and why was he incorrect
the theory of inheritance of acquired traits
what is artificial selection
when humans interfere and breed animals for desired traits like increased milk production or dog breed
what is a natural selection
the process by which biological organisms with favorable traits survive and reproduce more successfully than organisms that do not possess such traits
give an example of natural selection in action
if you have a population and some have short hair and other long hair and temp drops, the long haired ones will survive longer and pass their genes while short hair ones die off
why might one variation have a selective advantage over another variation
environment might favor one and be against the other. predators might see one color over another and keep attacking them
what is survival of the fittest
describes the idea that there is, in nature, competition to survive and reproduce
how are natural selection, adaptation, and fitness all interrelated
adaptation make an organism survive better in their enviroment, therefore making them more fit which means they will be more suckessful at living and passing their genes. natural selection places the pressure on which adaptations are benifical or determin
what is stabilizing selection
favors the average in-between individuals and selects against the two extremes
what is distruptive selection
favors both extremes while selecting against the avarage in-between
what is directional selection
favors one extreme
what is convergent evolution
when enviroment dictates the evolution of similar structures that have similar functions but are from different un-related species EX. wings of bat, bird or dragonfly
what is diverget evolution
one species gives rise to many species over time. these new species can tace origin back to a common ancestor EX. darwins finches
what are vestigial ogans
organs/structures that have no apparent function or beifit for the organism. EX. wisdom teeth, tail bone, eyes for blind cave fish
what are the major drive forces behind evolution
natural selection, enviromental depletion or formation, mass extinctions events, climate changes, new or reduced food sources
what is speciation
evolution of a new species because of geographic, reproductive isolation, or change in the number of chromosomes EX. polyploidy in some species of plants
what is adaptive radiation
when a population or a species evolves to fill in niches that were previously unoccupied
what is a mutation
any changes in the noral DNA sequence
what type of cell is believed to be on the earth first
eukaryotes
what major therory did lynn margulis propose
she was a scientist that tried to explain cellular evolution using the endosymbiont therory where one prokaryote swallowed another forcing it to become a mitochondriaon
natural selection occurs in which level
individual
adaptation radiation is associated with which type of evolution
divergent
shark, penguin, dolphin are examples of
convergent evolution
a modified structure seen among diffrent groups of descendants
homologous structure
in the earliest stages of develepment a tail and gill slits can be seen in rabbits, fish, birds
embryological evedence
exemplified by forelimbs of bats, penguins, and monkeys
homologous structure
the forelimbs of a flightless birds
vestigial structure
DNA and RNA comparisons may lead to evolutionary trees or cladograms
molecular evedince
birds and butterfly wings have the same function but diffrent structure
analogous structue
a body structure no longer used but may habe had a function in an early ancestor
vestigial
structure associated with divergent evolution
homologous structure
structure associated with convegent evolution
analogous structue
geographic isolation would fit into dis category
biogeographical evidence