macroevolution 9/30 - 10/4

fossil record

using fossils and their structure to determine the evolution of an organism

biogeography

the geographic distribution of organisms on earth follows patterns that can be explained by evolution

relative dating

the method used to determine the approximate age of a structure based on is physical relationship to surrounding geologic structures

absolute dating

exact age is determined by measuring the physical properties of the object itself (ex. carbon dating)

embryology

• compares and contrasts embryos of different species

• embryos of different species can have similarities that are not visible when organisms are fully formed

molecular evolution

DNA, RNA, and amino acids show evolution through differences in their sequences

homologous structures

similar physical traits that come from a common ancestor that are used for different purposes

analogous structures

features in organisms that are similar in unrelated species, caused by similar selection pressures

vestigial structures

traits inherited that are no longer needed/don’t benefit the organism anymore

divergent evolution

two species originate from a common ancestor (contain homologous structures and molecular homology)

convergent evolution

two unrelated species evolve similar traits (contain analogous structures)

parallel evolution

two species evolve similar traits independently (live in different environments)

coevolution

evolution of one species due to the evolution of another

gradual evolution

evolution that occurs by the gradual accumulation of small changes

transitional species

species that exist from one species becoming another

punctuated equilibrium

species diverge in spurts of relatively rapid change

phylogeny

the evolutionary history of a species or a group of related species

systematics

• a discipline focused on classifying organisms and determining their evolutionary relationship

• studied through fossils, molecules, and genes

cladistic analysis

shared characteristics depicted in a diagram

phylogenetic tree

depicts evolutionary relationship and reflects taxonomic hierarchy over time

monophyletic taxon

includes all descendants and the common ancestor

polyphyletic taxon

does not have the common ancestor of the organisms

paraphyletic taxon

a common ancestor and some of the descendants are included, but not all

origin of life

• 3.5 to 4 billion years ago

• life started with single cell bacteria

abiotic synthesis of organic monomers

miller & urey experiment

• stimulated the chemical environment of primitive earth

• produced a variety of molecules associated with life