chapter 14 how biodiversity evolves Flashcards
biodiversity
variety of life
species
group of organisms similar in every respect to color ,age, size and sex
Population
species occupying the same place at the same time
Community
all populations occupying the same place at the same time
ecosystem
a community and its physical environment
Biosphere
all ecosystems together
speciation
origin of new species by branching and non branching evolution
non branching evolution
Population changes and becomes a new species
branching evolution
1 or more species come from a parent species
what are the tempos of speciation
gradualistic model and punctuated equilibrium
Punctuated equilibrium
species are formed adruptly
exaptation
the processs where a structured used for one function is used for another
what are the reproductive barriers
pre zygotic barriers and post zygotic
pre zygotic barriers
doesn’t let zygote be formed by not letting sperm and egg meet
what are the types of pre zygotic barriers
temporal, habitat, behavioral, mechanical, gamete isolation
post zygotic barriers
doesn’t let the zygote survive or reproduce
what are the types of post zygotic barriers
hybrids inviability and sterility
speciation occurs by 2 mechanisms
allopathic and sympatric
allopatric
formation of new species by an ancestral population becoming separated by a geographical barrier
sympatric
formation of new species as a result of a genetic change that reproductively isolated the new species from the parent
how does macro evolution happen ?
natural selection, mutations, gene flow, genetic drift and continental drift
what is the ratio for carbon dating ?
1x10^12 C12 = 1C14
