Natural Selection-a more detailed look Flashcards
What are adaptive traits?*
The traits being selected are known as adaptive traits.
Example of adaptive traits?
Long fur when its cold.
Example of non-adaptive traits?
short fur when its cold.
What are the two types of environment that determines which traits are adaptive?
- Non-living environment
- living environment
What are the tree types of of natural selection due to the living environment?
- Competition for resources
- Predator-prey relationship
- Sexual selection
What is competition for resources?
Alleles allowing an organism to be better at getting resources from their environment are selected for.
What is predator-prey relationship?
Predators: alleles allowing them to be better at catching prey are selected for.
Prey: alleles allowing them to be better at escaping predators are selected for.
Predator-prey can lead to… and why?
It can lead to coevolution where two species are so important to the survival of each other that the evolution of one species will have a dramatic effect on the evolution of the other.
What is sexual selection?
Alleles that allow an individual to reproduce more easily are selected for.
What are the two different sources of sexual selection due to differences in gamete production between sexes?
- Male-male competition: Alleles allowing mates to outcompete their rivals for females are selected for.
- Female mate choice: Alleles that attract females are selected for.
What sexual selection can lead to?
Sexual dimorphism: when the two sexes of a species look very different from each other.
What are the three patterns of evolutionary change due to natural selection?
- Directional selection
- Stabilizing selection
- Disruptive selection
What is directional selection?*
Shifts towards one extreme.
What is stabilizing selection?*
Narrowed around the average.
What is disruptive selection?*
Divide toward both extreme.
