Evolution Flashcards
Lamarckian Evoluation
- new organs or changes in existing ones arose b/c of the needs of the organism
- amount of change was thought to be based on the disuse of the organ
Darwin’s Theory of Natural Selection
-pressure in the environment select for the organism most fit to survive and reproduce
Overpopulation
more offspring are produced than can survive
Variations
offspring naturally show differences in their characteristics compared to those of their parents
Competition
the developing population must compete for the necessities of life
Natural Selection
species have variations that give them advantage over other members of the species
Inheritance of the Variations
individuals that strive to adulthood reproduce and transmit favorable genes to offspring (genes will dominate gene pool)
Evolution of New Species
accumulation of favorable changes eventually results in such significant changes in the gene pool that we can say new species has evolved
Speciation
the evoluation of new species, which are groups of individuals that can interbreed freely with each other, but not with members of other species
demes
local populations formed within a species. if demes, become isolated, speciation may occur
phylogeny
a branching tree on which the common ancestor is found at the trunk and the modern species are found at the tips of the branches
convergent evolution
groups among the branches often develop similar traits
Parallel Evoluation
similar to convergent evolution but occurs when a more recent ancestor can be identified
Divergent Evolution
occurs when species with a shared ancestor develop differing traits due to dissimilarities between their environments
Adaptive Radiation
the emergence of a number of lineages from a single ancestral species
Population
includes all members of a particular species inhabiting a given location