Quiz 19: Evolution
What is an adaptation?
A trait or a behavior that can be inherited and that increases reproductive success.
Natural selection is the only mechanism that results in _____. Explain why.
Adaptations. This is because natural selection results in increasing alleles that increase reproductive success.
Describe gene flow and describe at least one example.
BY CHANCE, alleles move into a population. Example: Brown beetle wanders over to green beetle population introducing the brown color allele.
What is genetic drift? What are two sub-types of genetic drift? Give at least one example of genetic drift.
BY CHANCE, only a subset of alleles from the population is present in the next generation; Founder & Bottleneck effect; Example: there is a natural disaster and BY CHANCE only green beetles survive.
"Evolution leads to organisms perfectly adapted to their environments." Is this statement true or false? Explain.
False. Evolution will result in alleles that are more favorable to the reproductive success of a species, but species will never be perfectly adapted to their environment.
"New alleles arise when organisms need them." Is this statement true or false? Explain.
False. The introduction of new alleles is random.
Define what is meant by the "fitness" of an organism.
Fitness is the reproductive success.
Aside from mutation what are three other major mechanisms that cause evolution in populations?
Gene flow, genetic drift & natural selection
Can an individual organism evolve? ____ Can a population evolve? _____ ^Explain your answers.^
No; Yes; Evolution is based on genetic changes between generations. An individual is part of a specific generation and therefore can't evolve by itself.
Which is more affected by genetic drift, small populations or large populations?
Small populations
Explain the process of natural selection in a population of insects over time if the same pesticide is repeatedly applied for years and years.
The pesticide will kill off most mosquitoes, but leave primarily those resistant to the pesticide. The resistant mosquito population will increase as reproduction occurs and the population as a whole will become primarily resistant to the pesticide.
