The migration of reproductive individuals between populations results in a movement of alleles called:
Which of the following is the best measure of an organism's fitness?
the number of offspring it produces
Disruptive selection occurs when:
individuals with extreme values of a trait have greater fitness than individuals with intermediate values of the trait.
Three conditions are necessary for natural selection to occur. They are:
Variation in traits, inheritability of variation, differential reproductive success
Individuals with more favorable traits for a given environment will be more _________ and thus ___________ more than those with less favorable traits.
Exceptionally large babies increase a mother's mortality risk when giving birth and exceptionally small babies tend to die at birth or shortly afterward. For these reasons, birthweight in human babies is generally what type of natural selection? Explain your answer.
subject to stabilizing selection
What is the major difference between artificial and natural selection?
Natural selection acts without the input of humans; artificial selection requires human input.
Explain why some animals have evolved "extreme" traits related to mating habits (hint: think praying mantis or spider example)
While dying for the sake of reproduction may seem extreme, it increases the parents fitness if their alleles are passed to the next generation. It also allows nutrients from their bodies to be used to nourish either the female (praying mantis) or offspring (newly hatched spiders).