Unit 7 Test Flashcards
Who proposed theory of evolution?
Charles Darwin
What is evolution
Descent with modifications through genetic inheritance
What is a species
Organisms capable of interbreeding in nature and producing fertile offspring
Individual
A single member of a species
Population
A group of the same species in the same area
What evolves?
Populations evolve and become new species. Individuals do NOT evolve
Fossil record
Shows how species are similar
Vestigial structures
Body part still present in modern organisms but has no function
Homologous structures
Have different functions but are similar in structure (ex, wing, flipper, leg)
Analogous structures
Similar functions that did not evolve from a common ancestor (ex, insect wings and bird wings)
Embryonic development
Shared features in embryos of different species suggest common ancestors
Direct evidence
Evolution of a species that can be witnessed in a humans lifetime (ex, bacterial resistance)
What are Mrs Soltysiaks favorite flowers?
Sunflowers
What is a variation
Individuals in a population that differ from one another
What is Heritability
Variations that are inherited from parents, can be positive, negative or neutral
Disruptive selection
Favors both extremes in a trait
Stabilizing selection
Favors the median of a trait
Directional selection
Only one extreme is favored
Gene Pool
Collection of alleles found in the population
Allele frequency
Proportion of one allele compared with the rest of the alleles
Hardy-weinberg equilibrium
Phenotype frequencies change generation to generation, allele frequencies in a population stay the same because no evolutionary forces are acting on the population
For a population NOT to evolve-
- No mutations
- Individuals mate randomly
- Large population size
- Individuals do not enter or leave population
- Natural selection does not occur
