bio unit 4 Flashcards
the theory of evolution
explain and show that all living orgnisms on earth have their origin in other preexsisting animals. Meaing they have an evotionay past, and have unity in diversity.
evidence of evolution incude
fossil record
biogeography
homologies such as anatomical, embryobical, and molecular
gradualism
. in fossil records. if change is slow and steady there will be tranisitonal forms. thwy show intermeditate states of ancestors. show steady growth or organism.
puncutated
if evolution happens in quick jums, with big changes in fosssil record wiht little to no transitional forms
stasis
when fossils have not changed over a long period of time. alos called puncuated equilibrium.
what do quick jumps means
means that a big naturl disater took place or the missing parts fossil records are caused by irregualr fossil preservation.
biograpgy
how the change in geograpgy relates to how aniamls have evolved. like pangaea.
homologies
show how animals have common phycials features buecauses of evoltunary history and common ancestor.
homologous structure
have same structure but function is differnt with orgniams. formed through divergent evolution . was already there in ancestoer then just evolved for diff orgnisms.
molecular homology
shows similarty in DNA
vestigial structures
is there in the animal but no longer needed and has no use for. useless feature.ancestors once had but now not needed. like in the human the appendix.
analogous structure
similar in function but not same structure. means that they r not colosly related. formed by convergent evolution.
like fin, wing , and flipler.
darwin
he travllled to the galapagos islands and worte his book. notoceced that the finches have unique adapatations to their specific envrionemnt. diverse = variation
divergnet evolution also called
adaptive radiation, and the concept of gradulism.
evolution
change in the allele frequnecies in gene pool of pouplations over time. pouplation evolve not induvisuals. the cahnge in specices by natural slection.
evolutionay mechanism
natrural selction, genetic drift, gene flow, mutation, genetic recombinaton, non-ranodm mating.
gene pool
all allles for every gene present in a pouplation
allele frequnecy
the the number of times an allele occurs in the gene pool.
naturla selction
orgnisms most adapted to their environment survive and leave more offspring . by adaptions, fitness, and over production of offspring.
selection pressure
external agents which affect an organisms to survive
artificial selection
the slection pressure is not nature by humsn, such as anitibiotics and pesticides. bacteria can get resistence to it. causing the chemicals to get less effective.
MRSA
a staph infecton that is resistence to a rlly hard anitbiotic . people mill have to amputate to get it off the staph.
directional selction
for one extreme and not the other
stabiling selection
for moderate traits and against both extremes.
Diversifying selction
for both extrmees anf aganist all the moderates. most lilely creates speciation.
genetic drift
varition of allel frequnecy in small pouplation becuase of the randm disappearence of genes. is naturl but can be man made such as poaching or hunting. can lead to a loss of gentic variation.
bottle neck effect
poupltion suddlend get smaleer might happen because of naturl disaster.
founders effect
few induvisuslas start and found a new poupltion
gene flow
tansfer of alles from one poupltion to another. due to migration can intorduce new allele into poupaltion. increases variation fueal natrual slection and evolution.
speciation
when a poupltion becomes geneticly distinctive and can not breed with itself. has reproductng isolating mechanisms. is the creation of new species.
macroevolution
- large scale chnages in gene frequencies, long time like reptiles —> birds. occurs in patterns.
microevoultion
- small scale changes in gene frequnecies. wintin few generations and species. ex - change in fur
behaviroal isolation
isolating because of orgnisma haivng diffenrt behaviorals.
geographic isolation
population are seprated by physical barries.
temporla isolation
the orgnisms reproduce in diffent time such as season , time, month day
ecological isolation
2 species live in the same area but live in diff habitats within that area.
divergent evolution
related species become diff due to envrioment conditions. based on common ansestor. will result in homologous structures.
convergent evolution
unrelated organisms evolve similar adaptations due to similar environments. causes analogous structures.
