Evolution (E1) Flashcards
Evolution
Descent with modification
Shared heritage
Species share history
Theory
Explains the phenomena and explains the facts observed
Facts
Indisputable statements made through observations
Fossil records
Shows that organisms that lived long ago were different from those that we see today
Ancestral whale fossil changes
Whales losing their legs slowly over time
Homologous structures
Similar structures show some type of same ancestral animal (same molecules)
Ex.forelimbs are similar but different uses
Homologous molecules
Same molecules
3.8 billion years ago
Prokaryotic microorganism is where all life descended from
DNA & RNA
Deoxyribnuclieic acid, ribnucleic acid
DNA is the double strand of genetic information and RNA is the single strand of genetic information
Biogeography
Animals that are most similar and are the most closely related tend to be found in the same regions because evolutionary change is driven partly by geographical change
Wallace’s Line
The Birth Biogeography
Marsupials in Australia but like one in USA.
*This is due to pattern of distribution reflects pattern of relation
Ex. Galapagos finches, Hawaiian drosophila
Ex. Vicariance, mammal clades arose with continental breakup of Pangea
Direct observations of evolution
As genetic differences accumulate over time, micro evolution of closely related tax leads to macro evolution of higher taxa
Fruit fly starvation resistance experiment
Man controlled experiment testing which gene controls how long they can survive without eating and created a generation that survived 160 hours after 60 generations
Appendix function
Appendix is no longer really needed and it’s function is questionable
Pilomotor reflex
Goosebumps, hair erection
Coccyx
Where human tail is supposed to be if we had any
Tiktaalik
Fishapod, four legged fish
Alternative fossil records
All life arose once, cycle of creation, gradual change with increasing complexity
Vestigial trait
Unused traits fading away
Eyeless and aniridia genes
Mutation of pax6 gene, instruction for formation of eye
Vicariance
Separation of species through geological barriers
Coevolved clades
Cospeciation, the coordinated branching of interacting species
Parallel phylogenies
Coevolved clades have parallel phylogenies
Ex. Humans/chimps
