Unit 3+4 Misconceptions Flashcards
Natural selection and evolution are the same thing
False. Natural selection is just one of the many ways evolution occurs
Evolution is a random process
False. Parts of evolution such as natural selection and sexual selection are both non-random processes
Populations without genetic variation cannot evolve
True. Genetic variation (mutations) are the only way populations can evolve
Stronger and longer-lived individuals have higher fitness
False. Fitness refers to reproductive output not health, strength or size
Populations evolve but individuals do not
True. Change does not occur within generations; it occurs across or between generations
Most individuals in a population of fish that was isolated in a dark cave 500 years ago can no longer seen. This is because they didn’t use their eyes
False. Using or not using traits does not impact alleles.
Both harmful and beneficial alleles are passed on to offspring
True. Alleles are not inherited from parents one at a time; Chromosomes contain beneficial, harmful, and neutral alleles.
For natural selection to occur environmental change must occur
False. Natural selection does not require environmental change. Natural selection occurs when the following are present: heritable variation, the transmission of variation, some individuals reproduce and some don’t
Evolution typically occurs when most members of a population gradually adjust to a changing environment
False. Evolution is a sorting process that produces differences between generations. Change in frequency of alleles occurs, not changing of the alleles themselves.
New traits first appear in one individual at a time
True
Evolution often occurs because organisms and species are forced to change or go extinct
False. Nothing forces mutations. The variation factory cannot be manipulated, it is completely random. No outside force can cause beneficial mutations (or any mutations) to occur.
Natural selection tries to make species better through time
False. Natural selection doesn’t have a plan or goal.
Traits that are needed for survival are more likely to appear in a population
False. Mutations are random no matter what may be good or bad for survival.
In a population of organisms, traits can appear or be lost by the same mechanisms or processes
True. Traits are lost and gained by the same processes.
The fitness of an individual cannot be determined without knowing the environment the individual lives in
True. The fitness of a trait is dependent on the environment. The same traits can increase fitness in one environment while decreasing fitness in other environments.