Exam 16: How Populations Evolve

Which of the following likely reflects the presence of one or more gene mutations?

What is the relative biological fitness of an individual who is heterozygous for sickle-cell disease who lives in central Illinois vs.an individual who is heterozygous and lives in South Africa?

Which of the following is/are a biological "population?"

If the small groups of Viking explorers in Greenland and North America had survived and given rise to new populations,such a scenario would be an example of

You have been doing extensive research for 30 years on the frequency of coat colors (black,gray,white)in a guinea pig population located in the Andes Mountains.You suspect that your guinea pig population is undergoing stabilizing selection.If this is the case,what would you expect to find when you graph your data? Select all that apply.

In the case of the peppered moths in England,when Kettlewell set up cameras to document that more white or black moths were eaten by birds on clean or sooty trees,he was verifying which factor involved in evolution by natural selection?

A student proposes that left-handedness is a recessive trait and is hidden in much of the human population.A survey of his class of 36 students finds that 9 students are left-handed.Using the Hardy-Weinberg formula,what would be the expected allelic and genotypic frequencies in this theoretical population?

The difference in temperature preference between two populations of Daphnia water fleas is due to a mutation.The original population prefers temperatures near 20°C,while the mutant population prefers temperatures between 25°C and 30°C.Predict how natural selection might affect the geographical distribution of these two populations.

Hospital data shows that human infants born with an intermediate birth weight have a better chance of survival than those that weigh much less or much more.Larger than normal babies may have a difficult delivery,while smaller than normal babies may not be fully developed.What type of selection is occurring? Is the variability in birth weight in human populations increasing or decreasing?

All the members of a single species that occupy a particular area at the same time are known as a

Which of the following conditions is necessary to maintain the Hardy-Weinberg equilibrium?

What is the most plausible explanation for why the male of most bird species have elaborate plumage and mating rituals?

If the mutation rate of individual genes is taken to be about one in 100,000 genes per cell cycle across many organisms,we might expect evolution to proceed at a consistent rate for various forms of life.Which factor could make the accumulation of gene mutations faster or slower among different organisms?

Which of the following agents of evolution will help a population become better adapted to its environment?

The black bellied seed cracker,Pyrenestes,is a West African finch.Within the same geographic region,two subspecies of the finch are found.One subspecies has a large beak,which is efficient at cracking the hard seeds of the sedge,Scleria verrucosa.The other subspecies has a small beak,which is more efficient at eating the soft seeds of the sedge,Scleria goossensii.What type of selection occurred to produce this situation? Explain what a population distribution graph would look like that would depict this type of selection.

Dominant alleles are always the most common alleles in a population.

What do the founder effect and the bottleneck effect have in common?

Scientists have studied,in detail,the evolution of the peppered moth,Biston betularia,over the last two hundred years.The peppered moths rest on tree trunks and are a tempting treat for birds in the area.In the mid-1800s the trees in their England habitat were covered with lichens,which are a light,grayish-green color.Although color variations occurred,the vast majority of the moths were light-colored.Because their light coloration effectively camouflaged them against the lichens-covered trees,they were not as easily seen by birds as darker colored moths.The light-colored moths flourished. The environment changed,as the Industrial Revolution progressed.By 1900,the lichens had died and trees were coated with soot due to the industrial pollution.The lighter colored moths were no longer 'hidden' in their environment,and in fact,were easily seen by their predators.Their numbers dwindled.At the same time,the darker-colored moths flourished because of their ability to hide on the darkened trees. Describe what the initial normal population curve would look like before pollution.Describe what the population curve would look like after the Industrial Revolution and indicate what phenotype was favored.

Members of a population of guinea pigs exhibit one of three possible coat colors: black,gray,or white.Due to habitat loss,the population has recently colonized a new environment that has areas of black rocks as well as areas of white rocks.In addition,this new habitat contains several predators.If you could visit this population several generations later,what kind of phenotypic pattern,in terms of coat color,would you expect to find in this population?

Which of the following is required for natural selection to occur in a population?