History of Evolution

Question 1

What did Aristotle believe?

Answer 1

species are not variable, but fixed

developed linear scale called scala naturae/ great chain of being of complexity

Question 2

What did Linnaeus believe?

Answer 2

accepted that species were fixed

nested order of binomial classification

Question 3

what did lamarck do

Answer 3

proposed first coherent theory of evolution

1) traits are acquired or lost due to use/disuse
2) these traits are heritable

Question 4

What context was darwin’s idea was surrounded by

Answer 4

Hutton’s gradualism
Malthus’ population&raquo_space; resources
Lamarck use/disuse
fossil studies

Question 5

what evidence did darwin use to support theory of evolution

Answer 5

fossil record(glyptodons vs armadillos)
comparative embryology (tail in humans) as in lizards and pigs
homology of parts- dolphin, bat, cat, horse, human. same structure diff functions, eludes to common ancestor idea

variation in tortoiseshells shells and finch beaks in galapagos

artificial selection with pigeons, analogous to natural selection

diff in anatomy suggest adaptations (herbivore teeth vs carnivore teeth)

Question 6

4 postulates of Natural Selection

Answer 6

1. Indiv in pop vary
2. variants more or less adapted to env
3. diff survival and reproductive success for each indiv
4. favorable traits are passed down and inc in freq

Question 7

define natural selection

Answer 7

favorable traits are passed onto successive generations and inc in frequency due to diff success and reproduction

Question 8

what are the 2 major hypothesis in origin of species

Answer 8

1) evol is descent from common ancestors with modifications

2) natural selection acting on variation causes evolution

Question 9

probs w/ darwins theory of evol

Answer 9

1) gradualism is too slow for how young they thought Earth was
2) intricacy of adaptations- organisms are too advanced
3) Gaps in fossil record
4) where does variation come from?

Question 10

what was darwin’s repsonse to criticism

Answer 10

proposed pangenesis hypothesis (hereditary substances called gemules or pangenes are shed by all parts of organism and carried through bloodstream

Question 11

what did redisovery of mendel’s laws result in

Answer 11

particulate hypothesis replaced blending

Question 12

what is neutral theory of molecular evolution

Answer 12

molecular variation within and btwn species is explaind by drift, not selection

Question 13

tenents of modern synthesis(& evolution today)

Answer 13

• pops have variation from mutations(molecular basis known)
• pops evolve by random drift and non-random selection (importance of drfit emphasized)
• evol is gradual (sometimes)
• evol divergence gives rise to new species (sometimes few changes necessary
• given time, changes in micro evol –> changes in macroevol (true, but also are processes only on higher taxa)
• (molec basis of ptyic variation now known)
• (evol conditions favoring altruism and eusociality well understood
• (life’s evol history well-established)