Biology Exam Quiz: 2 (Evolution and Origin of Species)

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the frequency of individuals that are homozygous for this allele?

0.09

Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve the populations came in contact?

A behavioral reproductive isolating mechanism

Suppose 64% of a remote mountain village can taste phenylthiocaramide (PTC) and must, therefore, have at least one copy of the dominant PTC taster allele. If this population conforms to Hardy-Weinberg expectations for this gene, what percentage of the population must be heterozygous for this trait?

48%

A chance event or catastrophe can reduce the genetic variability within a population is called a ____________ event.

Bottleneck

During a study session about evolution, one of your fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconceptions? A) Spontaneous mutations can result in the appearance of new traits B) Only favorable adaptations have survival value C) Characteristics acquired during an organism's life are generally not passed on through genes D) Disuse of an organ may lead to its eventual disappearance.

Characteristics acquired during an organism's life are generally not passed on through genes.

Darwin Postulated

Characteristics of offspring vary, and these variations are heritable More offspring are produced than can survive; there is competition for resources Most characteristics are heritable, passed from parent to offspring

Which of these conditions are always true of populations evolving due to natural selection? Condition 1: The population must vary in traits that are heritable Condition 2: Some heritable traits must increase reproductive success Condition 3: Individuals pass on most traits that they acquire during their lifetime

Conditions 1 and 2

Darwin and Wallace's theory of evolution by natural selection was revolutionary because it _____________.

Dismissed the idea that species are constant and emphasized the importance of variation and change in populations

A biologist doing a long-term study on a wild spider population observes increased variation in silk thickness. Which of the following could the spider population be experiencing?

Disruptive Selection

_______________ evolution is when two species diverge from a common ancestor and develop different characteristics.

Divergent

Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true?

Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted.

Convergent Evolution is the evolution of dissimilar features in distantly related group. T/F

False

In 1986, a nuclear power accident in Chernobyl, USSR (now Ukraine), led to high radiation levels for miles surrounding the plant. The high levels of radiation caused elevated mutation rates in the surviving organisms, and evolutionary biologists have been studying rodent populations in the Chernobyl area ever since. Based on your understanding of evolutionary mechanisms, which of the following most likely occurred in the rodent populations following the accident?

Mutation led to increased genetic variation.

The peppered moth provides a well-known example of natural selection. The light-colored form of the moth was predominant in England before the Industrial Revolution. In the mid-nineteenth century, a dark-colored form appeared. the difference is produced by a dominant allele of one gene. By about 1900, approximately 90% of the moths around industrial areas were dark colored, whereas light-colored moths were still abundant elsewhere. Apparently, birds could readily find the light moths against the soot-darkened background in industrial areas and, therefore, were eating more light moths. Recently, use of cleaner fuels has greatly reduced soot in the landscape, and the dark-colored moths have been disappearing. Should the two forms of moths be considered separate species.

No

After speciation has occurred, two separate but closely related species may continue to produce offspring in an area called the hybrid zone. These events may result, depending on reproductive barriers and the relative fitness of the hybrids.

Reinforcement Fusion Stability

Prezygotic vs postzygotic barriers, Temporal Isolation, Habitat isolation, and Behavioral isolation are all components of the process called __________ isolation.

Reproductive

Soon after the island of Hawaii rose above the sea surface (somewhat less than one million years ago), the evolution of life on this new island should have been most strongly influenced by ________.

The founder effect

Evolution has no long-term purpose or direction. T/F

True

Natural selection does not create new traits, but edits or selects for traits already present in the population. T/F

True