Chapter 22 Flashcards
What were Darwin’s 4 inferences?
- Members in population have varying traits
- Traits are heritable
- All organisms overproduce more than environment can hold
- Many individuals do not survive (competition for limited resources)
What were Darwin’s 2 conclusions?
- Individuals with with traits that give them better chance to survive tend to live longer
- Unequal reproduction and survival rates lead to an accumulation of favorable traits over generations
What does natural selection increase?
Match between organism and its environment over generations
What is the primary cause of evolutionary change?
Natural selection
What are the 4 types of data that support the theory of evolution?
- Direct observations of evolution
- Fossil record
- Homology
- Biogeography
How does natural selection occur when destroying HIV strains with drugs?
Addition of drugs to kill pathogen HIV strains selects for HIV strains with immunity to the drugs. Over time, their frequency will increase as they have the beneficial trait of resistance in the environment
What is homology?
Similarity between organisms resulting from common ancestry
What are homologous structures?
Structures of different organisms that resemble each other in pattern because they have evolved from a common ancestor
What are vestigial structures?
Homologous structures that are no longer in use
What are analogous structures?
Structures in different organisms that resemble each other due to similar adaptation in similar environment; does not indicate relatedness!
Convergent evolution
Independent evolution of similar features in similar environments in different species
What is the main factor that influences biogeography?
Continental drift from an original land mass, Pangaea
How do endemic island species give evidence to continental drift?
They most resemble species on the nearest mainland; continental drift separated the populations and they have adapted to their new environments
How does the fossil record give evidence for evolution?
Shows that past organisms differ from current and some have become extinct due to beneficial evolutionary changes
Do poorly adapted organisms produce offspring?
Yes, just not as many as adapted organisms (they have a lower fitness because of this)
