Question 1

Ancestors of the Galapagos finches had two different types of seeds to eat on some islands.Some seeds were very small,and required small beaks to handle.Other seeds were very large and required large strong beaks to crack.This led to ____ among the Galapagos finches.

Accepted Answer

Disruptive selection favors either extreme phenotype over the intermediate.Please see section 12.5 for more information.

Question 2

A male peacock has enormous tail feathers that it uses in mating displays to attract females.While the tail feathers are an advantage in mating,what is the potential disadvantage of these feathers to the male?

Accepted Answer

The basic idea behind any examples of sexual selection is that the trait which is sexually selected is a disadvantage,so a superior genotype can show itself by surviving in spite of such a handicap.Please see section 12.6 for more information.

Question 3

If an environment changes rapidly,organisms with ____ will be more likely to survive and reproduce.

Accepted Answer

Rapid change does not leave time for new mutations to arise,so existing advantages phenotypes win out evolutionarily.Please see section 12.3 for more information.

Question 4

A population declines when

Accepted Answer

Population declines can be driven by many things which accelerate the death rate,such as disease and predation.Please see section 12.7 and "Investigating Life" for more information.

Question 5

Use the Hardy-Weinberg equations: p + q = 1 and p² + 2pq + q² = 1.If the dominant allele frequency is 0.8,then what percent of the population will be homozygous dominant?

Accepted Answer

p² is ther proportion of the population which is homozygous dominant.Please see section 12.4 for more information.

Question 6

Farmers and horticulturalists bred broccoli,cauliflower,kale,and cabbage from the wild mustard plant through

Accepted Answer

Artificial selection is like natural selection except that they selection is made consciously by humans rather than by blind natural forces.Please see section 12.2 for more information.

Question 7

The North American bison was hunted to near-extinction in the 1800s.It has since recovered,but with decreased genetic diversity.This is an example of

Accepted Answer

Bison populations crashed,leading to refounding of current populations by a small group of survivors.Please see section 12.7 for more information.

Question 8

Ancestors of giraffes with shorter necks could not reach branches high up in trees for food.This led to ____ for giraffes with longer necks.

Accepted Answer

Directional selection pushes a population towards one phenotype.Please see section 12.5 for more information.

Question 9

The founder effect

Accepted Answer

Founder effects involve small founding populations,such as those which manage to reach small islands distant from existing populations.Please see section 12.7 for more information.

Question 10

Alleles conferring red plumage to cardinal males are common because red plumage

Accepted Answer

Sexual selection is based on one sex selecting mates based on their appearance.Please see section 12.6 for more information.

Question 11

Babies that are at a low birth weight are more likely to have health problems,while women will have difficulty delivering babies with high birth weight.Together this leads to ______ for babies of average birth weight.

Accepted Answer

The safest birth weight for a baby,for both successful birth and survival afterwards,is an intermediate weight.Please see section 12.5 for more information.

Question 12

Sexually dimorphic features do not include

Accepted Answer

Sexual dimorphism is generally restricted to phenotypes involving physical features.Please see section 12.6 for more information.

Question 13

Evolution answers the question of how life began.

Accepted Answer

Evoltion is a theory which explains how new species orginate.Please see section 12.1 for more information.

Question 14

When looking at the effect of fishing on average fish size over time,what hypothesis were the researchers testing?

Accepted Answer

The researchers wanted to determine if fishermen keeping fish over a size limit would lead to smaller fish being caught in the future.Please see section 12.7 and "Investigating Life" for more information.

Question 15

The few ancestors of the Galapagos finches who colonized the islands is an example of

Accepted Answer

The finches that managed to reach the Galapagos Island were few because of the great distance from South America to the Galapagos as well as the usually short distance travelled by finches.Please see section 12.7 for more information.

Question 16

Darwin obtained which of the following in the Essay on the Principle of Population by Malthus?

Accepted Answer

Malthus painted a picture of a grim world,which holds true for animals but which has not held true in human populations,especially since the Green revolution.Please see section 12.2 for more information.

Question 17

Use the Hardy-Weinberg equations: p + q = 1 and p² + 2pq + q² = 1.If the dominant allele frequency is 0.8,then what percent of the population will be heterozygous?

Accepted Answer

Calculating 2pq gives the percentage of heterozygotes.Please see section 12.4 for more information.

Question 18

The bottleneck effect

Accepted Answer

Disasters and diseases can cause crashes in population,which can,in turn,lead to bottleneck effects.Please see section 12.7 for more information.

Question 19

Historically fishermen kept larger fish and left smaller juvenile fish.Over time the average size of the fish would

Accepted Answer

Taking larger animals by hunting or fishing always tends to select for smaller ones.Please see section 12.7 and "Investigating Life" for more information.

Question 20

Today,40% of hospital Staphylococcus infections are resistant to all antibiotics except one.

Accepted Answer

Overuse of antibiotics has led to many more antibiotic resistant bacteria being in the environment,especially in hospitals.Please see section 12.3 for more information.

Quiz 12: Forces of Evolutionary Change