Natural Selection + Evolution Flashcards
What was ARISTOTLE’s idea of evolution?
- great chain of being
- species were “fixed” types
- order based on size + complexity
- biblically inspired
What was the FRENCH ENLIGHTENMENT’s idea of evolution?
- earth older than biblical belief (4000 yrs)
- first mention of scientific earth formation
- species were “diverse” types
- incorrect “use and disuse” and “inherited acquired characteristics”
What was DARWIN’s idea of evolution?
- mention of endemic species
- saw fossils as evidence of evolutionary change
- variation on galapagos
- life forms evolved
What are the steps for evolution?
- competition
- variation among individuals
- heritable variation
- natural selection
- adaptation
What is adaptation?
- traits that help organism survive and reproduce
- are often compromises
How does natural selection affect adaptations?
individuals with best fit adaptations for given environment will survive via natural selection
What is fitness?
the lifetime number of progeny one individual produces
What is evolution?
the genetic changes in a population
What is speciation?
the emergence of new species from one root species
What is adaptive radiation?
the sudden diversification of a phylogenetic tree caused by factors such as new niches opening, extinctions, geological isolation etc
What are the types of speciation?
gradualism: slow changes, not supported by fossil record
punctuated equilibrium: rapid diversity period followed by slow/still period
What is natural selection?
ongoing process where random evolutionary changes are favoured by nature in a consistent, orderly way
