Evidence for Evolution Flashcards
1
Q
Evolution vs. Natural Selection
A
- Evolution: genetic changes (allele frequency) over time, through generations in a population
- Natural Selection: operates on phenotypes, not genotypes
2
Q
Evidence: fossils
A
- Show morphological changes over millions of years
- Vestigial structures show evidence of previously important body parts
3
Q
Evidence: bad design
A
- Ex: left recurrent laryngeal nerve runs from the brain to the larynx by looping around
- Inefficient design today, but originated in fish, where it was a direct link
4
Q
Biogeography
A
- Distribution of life across continents (Pangaea)
- Ex: marsupials in Australia and the Americas
5
Q
Convergent evolution
A
- Similar adaptations without a common ancestor (it was beneficial to evolve with a similar morphology)
- Ex: non-crabs converging into crab-like forms
6
Q
Humans inadvertently create selection
A
- Peppered moths, harvesting, hunting
- Those with traits most fit for survival will be seen at a higher frequency over time
7
Q
Molecular genetics
A
- DNA suggests a universal origin of life
- Speciation (observed through genetic differences) appears to accumulate at a constant rate
- Ex: increase in pseudogenes for olfactory receptors in cetaceans when they returned to the water