BIOL214 lecture 9

evolution

accumulates inherited changes in a population over time

population

Group of individuals of the same species living in the same location

microevolution

the short term adaptations that result from changes in the environment (changes in allele frequency)

macroevolution

the process of the development of new species from common ancestors

phylogeny

the history of descent with branching

phylogenetic tree

the process of speciation can be depicted here, where branches represent diverging populations

sister groups

when two taxons share a common ancestor not shared by any other group

monophyletic group

includes a common ancestor and all of its descendants

paraphyletic group

includes a common ancestor and some, but not all, of its descendants

polyphyletic group

does not include the common ancestor

homologous

characters that are similar bc of common descent

homoplasy

similarities due to adaptation by different species

synapomorphies

shared derived characteristics

cladistics

phylogenetic reconstruction on the basis of synapomorphies

outgroup

a group that we know falls on an earlier branch in the tree

principle of parsimony

the best fit tree is the one that has the fewest number of changes bc it minimizes the total number of independent origins of character states

burgess shale

a sedimentary formation that preserved the deep seafloor of 505 million years ago

messel shale

formed in a lake in now Germany about 50 million years ago, and it released toxic gases and suffocated local animals

biogeography

the study of the distribution of species and ecosystems in geographic space and through geological time

Archaeopteryx

An intermediate fossil that shows both reptile and bird characteristics

tiktaalik

supposed link between fish and tetrapods