Flashcards in Natural Selection Deck (19):
Nature selects organisms that are...
Adequate enough to grow up (survive), mate and produce offspring
Natural selection is a ________ process
A nonrandom process by which traits are selected for by nature because they provide some survival benefit
4 main principles of natural selection
descent with modification
In any population not all organisms are the same
More babies are born than will survive
Something that the organism has that is beneficial (a trait)
Descent with modification
The next generation with slightly different characteristics
The measure of survival ability and ability to produce more offspring in the population
Unequal number of offspring produced by breeding pairs of the same species
Natural selection acts on...
Existing variation and traits that already exist
3 modes of selection
1 of 2 extreme phenotypes is clearly favored
The middle phenotype is favored
Both extreme phenotypes are favored, middle is no good
Why does sexual selection happen?
Females have a much higher cost of reproduction (more limited than males)
Types of sexual selection
Competition among males in a population for reproductive rights with a female