Lecture 3 - Evidence for Evolution Flashcards
Why do sticklebacks have more lateral plates in the ocean than in lakes?
It is more energetically costly to find the ions needed to build lateral plates in an environment where predation is not as big of an issue.
How do reduced lateral plates effect sticklebacks in lakes?
They grow larger, have higher overwinter survival, and breed sooner.
What are 4 direct observations about natural selection?
- It can occur in response to introduced species
- It is a process of editing (selects for traits)
- It can occur rapidly in species that produce new generations quickly
- It is dependent upon time and place
What is the difference between homologous and analogous traits?
Homologous traits are similar traits due to common ancestry and analogous traits are similar traits that evolve separately.
What is phenotypic plasticity?
A genotype that produces different phenotypes in response to the environment.
What is developmental phenotypic plasticity?
When the phenotype of an organism changes while developing and becomes fixed at development.
What is seasonal phenotypic plasticity?
When the phenotype changes during the organisms life depending on the season.
What is the difference between phenotypic plasticity and natural selection?
Natural selection occurs over many generations and results in heritable traits. Phenotypic plasticity occurs in a single generation and does not produce a heritable phenotype.
