Midterm: Evolution Foundation Flashcards
understand given learning objectives
Genes:
a. Code for Proteins
b. Express phenotypes
c. have many forms
If beak size is determined by which foods nestlings eat most frequently during their early development and is NOT an inherited trait (aka not determined by genes), would the population evolve in response to drought?
No. Evolution depends on pre-existing characteristics
Describe Genetic Drift
a random evolutionary mechanism that does NOT result in better adapted populations
Define Evolution
Genetic variation that act on pre-existing variation. However, ONLY POPULATIONS EVOLVE. They are better suited for an environment due to phenotypes.
Mutations occur:
RANDOMLY to cause ALL genetic variation
Having red fur is extremely advantageous relative to all other fur color phenotypes in a population of sloths. Predictably, red is the most common fur color phenotype in the population and this characteristic is heritable. Which of the following is the most likely explanation for the high frequency of red fur color relative to all other color phenotypes?
a. Many individuals transitioned from other colors to red-furred as this was advantageous for their survival and reproduction.
b. Many individuals in the population likely experienced the mutation that resulted in red fur coloration as it was highly advantageous in the sloths’ environment.
c. Genetic drift resulted in the beneficial allele becoming most common over time because it conferred survival advantages.
d. None of the above.
None of the above.
Individuals cannot change phenotype upon will. Evolution acts on POPULATIONS, not individuals. Genetic drift did not occur due to a stationary species.
Evolution can occur with 4 mechanisms, which are:
a. Natural Selection
b. Genetic Drift
c. Gene Flow
d. Mutation
Which mechanism(s) are adaptive evolution and which are non-adaptive?
ADAP:
Natural Selection
NON-ADAP:
Genetic Drift, Gene Flow, Mutation
Define Gene Flow:
movement of alleles from one population to another
Define Genetic Drift:
RANDOM events that change allele frequency between generations
Does evolution always result in better adapted populations?
No. It is unpredictable so random events may or make not make the population better suited.
Can populations evolve if the population has the same alleles?
No. It will keep those genotypes within the gene pool. Evolution can work only on pre-existing variation.
If a population with the same alleles had a new predator, could they evolve to be “more fit”?
No. They will die out or decline. Evolution is not goal oriented. Organisms can’t adapt because they “need” to.
If red, green, and yellow birds want to immigrate to Iceland, which one will choose to go?
All of them. As humans, we don’t see a chance to camouflage, thinking we will be better adapted than another. Birds migrate because they choose to migrate. This is gene flow, which is RANDOM
