Chapter 3: Evolutionary thought and theory Flashcards
3 Principles of science
- there is a real and knowable universe
- the universe operates according to understandable laws
- these laws are unchanging
4 Methods of science
- Create one or more testable hypotheses to explain observations or answer questions
- Test the hypothesis (or hypotheses)
- Accept, modify or reject the hypothesis
- Continually reevaluate the hypothesis as new data becomes available and new hypotheses are created
Hypothesis
must be testable, there must be some way to collect & analyze data to support or reject it
Theory
usually made up of multiple hypotheses and data that support the claim
6 Key concepts in evolutionary theory
Mutation, natural selection, sexual selection, gene flow, genetic drift, adaptive radiation
Mutation
- Errors in the replication of DNA, the ultimate source of variation within populations
- Can occur simply as copying errors or from exposure to radiation, chemicals and viruses
- The reason why bipedalism and larger brains emerged in humans
Sexual selection
Personal mate selection (choosing a mate based on physical features or cultural factors)
Gene flow
When genes move between populations that are members of the same species but who do not normally mate together
Genetic Drift
A random factor in evolution,
When changes in allele frequency occur by chance (ex- when a small group leaves its parent population and begins a new population elsewhere)
Adaptive radiation
Occurs when a species rapidly adapts to an ecological niche, often expanding its population quickly and diversifying into multiple species
What 2 models pertain to the speed at which evolution occurs
Gradualism & Punctuated equilibrium
Gradualism
suggests a slow steady change with a new species eventually emerging
Punctuated Equilibrium
suggests a slow steady change occasionally interrupted by short periods of significant change
explains the lack of transitional forms in the fossil record
Species
a population of individuals that can mate and produce fertile offspring in the wild
Speciation
the process by which new species emerge, can happen in numerous ways such as geographic isolation or a single population of species that evolves into another species