Exam 15: Processes of Evolution

Sickle cell anemia evolved in Africa.Although homozygotes of this allele have the anemia,the sickle cell allele of $\beta$ -globin has reached high frequencies because individuals with one copy of the allele have a resistance to malaria.The maintenance of both the normal and sickle cell alleles is therefore due to

Although Darwin's voyage aboard the HMS Beagle took him around the world,most of his observations on natural history were made on the continent of _______ and its nearby islands.

Which statement about genetic drift as an evolutionary factor is true?

Use the following to answer questions : A cricket has a diploid genome of 1.2 billion base pairs.Assume that there are about 200,000 individuals in the population and that the mutation rate is one per 100 million base pairs. -On average,how many new mutations will occur in an individual cricket?

Natural selection can be defined as

A small population of sawflies that was once connected to a larger one but is now isolated is no longer experiencing

Use the following to answer questions : Suppose the size of a population of marmots is 300. -According to genetic drift theory,what is the probability that a newly arisen mutation will become fixed in this population?

Which vegetable is most likely to be produced from wild mustard,Brassica oleracea,given continued selection for larger flower clusters?

A fairly large population of sparrows has a much greater than expected proportion of heterozygotes at many loci.Which explanation is most plausible?

Genes from many isolates of the influenza virus have been sequenced.In certain regions of the genome,nonsynonymous substitutions have been found to occur much more frequently than synonymous substitutions.From this pattern we can infer that

Use the following to answer questions : A gene family has been accumulating nucleotide substitutions at a rate of 0.25 substitutions per million years.On average,there have been 80 substitutions between the common ancestor of this gene family and each of the various living forms of this gene. -How many substitutions are likely to have evolved between any pair of living forms of genes from this gene family?

Which vegetable is most likely to be produced from wild mustard,Brassica oleracea,given continued selection for larger stems and flowers?

Studies of enzyme genotypes and flight in Colias butterflies showed that

In which group would you expect the greatest extent of lateral gene transfer?

Darwin published The Origin of Species

Charles Darwin's early thinking about geology was shaped by the work of _______,who claimed that Earth's features are shaped continuously by slow-acting forces.

Use the following to answer questions : Suppose you have a population of flour beetles with 1,000 individuals.Normally the beetles are red;however,this population is polymorphic for a mutant autosomal body color,black,designated by bb.Red is dominant to black,so BB and Bb genotypes are red.Assume the population is at Hardy-Weinberg equilibrium,with equal frequencies of the two alleles. -What would be the expected frequencies of the homozygous dominant,heterozygous,and homozygous recessive (in that order)after 100 generations,assuming that no selection or other evolutionary processes are operating?

Which evolutionary process creates new genetic variation?

Which statement about evolution is false?

Darwin's breeding of pigeons