PROCESS OF EVOLUTION Flashcards
Which of the following describes a vestigial structure?
a) A structure that serves a new function
b) A trait that was useful in an ancestor but is no longer functional
c) A mutation that increases an organism’s fitness
d) A genetic change due to artificial selection
b) A trait that was useful in an ancestor but is no longer functional
What is the primary reason why natural selection cannot produce perfectly adapted organisms?
a) Evolution is goal-directed.
b) Genetic variation is limited.
c) Organisms actively try to evolve.
d) Evolution follows a fixed path.
b) Genetic variation is limited.
Mutations can be beneficial, neutral, or harmful for the organism, but mutations do not “try” to supply what the
organism “needs.” In this respect, mutations are _________ — whether a particular mutation happens or not is unrelated to how useful that mutation would be.
random
What term describes the relationship between two species that influence each other’s evolution, such as pollinators and flowers?
a) Artificial selection
b) Genetic drift
c) Coevolution
d) Gene flow
c) Coevolution
All of these mechanisms can cause changes in the frequencies of genes and other genetic elements in populations,
and so all of them are mechanisms of evolutionary change.
Mutation
Migration
Genetic Drift
Natural Selection
____ can introduce new gene combinations into a population. This genetic shuffling is another important source of genetic variation
Sex
_____________ is the process through which a fertilized egg, the earliest stage of an embryo, becomes an adult organism. Throughout this, an organism’s genotype is expressed as a phenotype, exposing genes and the genetic elements that control their expression to the action of natural selection.
Development
________ is any movement of genetic material from one population to another (e.g., through migration) and is an
important source of genetic variation.
Gene flow
What is the primary difference between natural selection and genetic drift?
a) Natural selection is random, while genetic drift is not.
b) Genetic drift is random, while natural selection is influenced by environmental pressures.
c) Genetic drift only occurs in large populations.
d) Natural selection is only caused by mutations.
b) Genetic drift is random, while natural selection is influenced by environmental pressures.
Which of the following is NOT a mechanism of evolutionary change?
a) Mutation
b) Genetic drift
c) Gene cloning
d) Natural selection
c) Gene cloning
The process by which modern organisms have descended from ancient ancestors.
Evolution
The movement of genetic material from one population to another, also called migration.
Gene flow
When a beetle population shifts from mostly green-colored individuals to mostly brown-colored individuals due to bird predation, which evolutionary mechanism is at work?
a) Genetic drift
b) Gene flow
c) Natural selection
d) Artificial selection
c) Natural selection
____________ is one of the basic mechanisms of evolution.
In each generation, some individuals may, just by chance, leave behind a few more descendants (and genes, of course!)
than other individuals.
Genetic drift
There are three primary sources of new genetic variation:
Mutation
Gene flow
Sex
The basic mechanism of evolutionary change that occurs when a population experiences random changes in gene frequency due to chance.
Genetic drift
___________ is the process by which modern organisms have descended from ancient ancestors.
Evolution
Which type of mutation does NOT directly affect evolution?
a) Germline mutations
b) Mutations in reproductive cells
c) Somatic mutations
d) DNA replication errors in gametes
c) Somatic mutations
The process through which a fertilized egg develops into an adult organism, influencing evolutionary changes.
Development
_________ — also called migration — is any movement of individuals, and/or the genetic material they carry, from
one population to another.
Gene flow
__________ are changes in the information contained in genetic material. (For most of life, this means a change in
the sequence of DNA.)
Mutations
What is the main source of new genetic variations in a population?
a) Selective breeding
b) Mutations
c) Artificial selection
d) Natural disasters
b) Mutations
What term describes the ability of an organism to survive and reproduce relative to others in its population?
a) Fitness
b) Adaptation
c) Genetic drift
d) Coevolution
a) Fitness
Which process is most likely responsible for the introduction of new alleles into a population?
a) Natural selection
b) Mutation
c) Genetic drift
d) Evolutionary fitness
b) Mutation
A form of natural selection where certain traits are favored because they increase an organism’s ability to attract mates.
Sexual selection
Evolutionary biologists use the word __________ to describe how good a particular genotype is at leaving offspring in the next generation relative to other genotypes.
fitness
A sudden volcanic eruption wipes out most of a population of insects, leaving only a small group of survivors. The change in gene frequency in this population is an example of:
a) Natural selection
b) Gene flow
c) Genetic drift
d) Artificial selection
c) Genetic drift
TRUE OR FALSE
Not all mutations matter to evolution.
The only mutations that matter for the evolution of life’s diversity are those that can be passed on to offspring. These
occur in reproductive cells like eggs and sperm and are called germline mutations.
TRUE
Which of the following is an example of artificial selection?
a) Birds developing longer beaks to access food
b) Farmers breeding cows that produce more milk
c) Bacteria evolving resistance to antibiotics
d) Moths changing color due to pollution
b) Farmers breeding cows that produce more milk
What type of selection results in extreme traits, such as large antlers in male deer or bright plumage in male birds?
a) Artificial selection
b) Sexual selection
c) Stabilizing selection
d) Disruptive selection
b) Sexual selection
Which of the following is NOT a primary source of genetic variation?
a) Mutations
b) Genetic drift
c) Gene flow
d) Sexual reproduction
b) Genetic drift
