micro and macroevolution Flashcards
what is co-speciation
a form of coevolution in which the speciation of one species dictates the speciation of another species
what are clades
aka a monophyletic group is a group of organisms composed of a common ancestor and all its lineal descendants
what is meant by the term analogous
structures which have separate evolutionary origins but are superficially similar as a result of convergent evolution
define convergent evolution
the independent development of similar traits or features in unrelated or distantly related species
define macroevolution
looks at evolution on a grand scale looking at the over-arching history of life
what are the four mechanisms of change
- mutation
- migration
- genetic drift
- natural selection
what are the different patterns of macroevolution
1) stasis
2) character change
3) lineage splitting
outline the pattern of macroevolution - stasis
no change for a long period of time e.g. the coelacanths
outline the pattern of macroevolution - character change
when lineages change quickly or slowly
outline the pattern of macroevolution - lineage splitting/ speciation
the formation of a new and distinct species in the course of evolution
what is microevolution
evolution on a small scale within a single population = narrowing the focus to one branch of the tree of life
define a population
a group of organisms that interbreed with each other = all share a gene pool
what are the two ways of detecting microevolution
- a change in gene frequency in a population
- a group of organisms that share a common gene pool
what is the problem with the definition of a population referring to interbreeding individuals
hard to apply to organisms that reproduce only or mainly asexually
also many species form hybrids etc
define speciation
a lineage splitting event that produces two or more sperate species
