Module 3: Evolution, Origin of Species, and Populations BIO102 Final Exam Review

Darwin's 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

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

0.09

According to the Hardy-Weinberg principle, allele frequencies ____________.

Are stable unless exposed to an evolutionary force

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 misconception?

Characteristics aqquired during an organisms life are generally not passed on through genes

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

Condtions 1 & 2

After speciation occurs, populations are still capable of recovering (T/F)

False

Convergent evolution is the evolution of dissimilar features in distantly related groups (T/F)

False

Ultimately, species remain separate because they do not share geographical regions (T/F)

False

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.

Fusion Reinforcement Stability

In order for organisms to change over generations, there must first be ________.

Genetic variation

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 population following the accident?

Mutation led to increased genetic variation

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

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 if the populations came in contact?

a behavioral reproductive isolating mechanism

The basis of __________ speciation is perpetual separation populations

allopatric

A chance event of catastrophe can reduce the genetic variability within a population is called a ___________ event.

bottleneck

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

divergent

Prezygotic vs. postzygotic barriers, temporal isolation, habitat isolation, and behavioral isolation are all components of the process called ________ isolation.

reproductive

A mouse population that originally ranges from white to black becoming mostly grey over several generations is an example of what type of natural selection?

stabilizing

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