Lecture 19: Intro to Evolution Flashcards
evolution
changes in allele frequencies in populations over generations
what type of science inspired Darwin’s idea of slow gradual change over long periods of time
geology
gradualism
theory that changes of organic life and Earth occur through gradual increments
theory of uniformitarianism
states that the same geological processes that occur today have operated throughout Earth’s history
what type of science inspired Darwin’s idea of competition?
economics(Thomas Malthus)
What are the four observations that led to evolution by natural selection?
- Overproduction
- Unequal Survival and Reproduction
- Heritable Variation
- Nonrandom Survival and Reproduction
Observation 1: Overproduction
more offspring born each generations than will survive and reproduce
Observation 2: Unequal Survival and Reproduction
some survive longer and have more offspring than others
Observation 3: Heritable Variation
individuals have variation, so offspring are led to resemble parents
Observable 4: Nonrandom Survival and Reproduction
survival and reproduction are based on phenotype and the best adapted individuals have the most offspring
natural selection
better adapted individuals will have better survival and reproduction–>the traits that make them better adapted will increase in frequency over time
Lamarck’s 2 (wrong) ideas
- use and disuse
- inheritance for acquired traits
Use and Disuse Idea
body parts used–>stronger; body parts not used–>deteriorate; ex: giraffe stretches neck so their neck gets longer(wrong)
inheritance of acquired traits
traits acquired during lifetime are passed to offspring; ex: giraffe neck stretched–>passes on longer neck(wrong)
fitness
reproductive success
