Ch 13

The ease with which humans travel across the globe is likely to increase

gene flow

The relationship of the genome to an organism is the same as that of the _____- to a population

gene pool

After his journey on the HMS Beagle, Darwin made this now famous sketch in his notebook. Which ideas does it represent

All species are linked to one another by common ancestory Species descend from other species just as naturally as children come from parents All species are connected to one another in a family tree

Suppose that every few years all people over 6 feet tall do not have any children. How will this affect the human population

Alleles that promote "tallness" will decrease in frequency

Which of these gametes contain one or more recombinant chromosomes

B, C, F, and G

Darwin and Wallace made independent observations in different parts of the world. Which statements are true?

Both witnessed nature up close and realized it was a battlefield with massive casualities Both observed slightly different species on nearby islands and concluded that species could change over time Both collected huge number of specimens and realized that individuals vary within species

A sudden volcanic eruption kills many members of a population of elk. By chance, the individuals that remain do not have the same mix of genes as the original population

Bottleneck effect

Although millions of prairie chickens once roamed the Midwest, their numbers dwindled to only 50 individuals in the 1990s. These few individuals have since produced a large population. The genetic variation among the current population is quite low

Bottleneck effect

Hardy-Weinberg equilibrium maintained only if

Large population size, no gene flow, no mutation, random mating, no natural selection

What did Wallace conclude from observing that the bones in manatee flippers look similar to the bones in a human arm and hand

Manatees' arm and finger bones are evidence that manatees share a common ancestor with land mammals

Homologous pairs of chromosomes are lined up independently of other such pairs during

Metaphase I

When Charles Darwin set sail on the HMS Beagle, what did he and most of his contemporary scientists think about the origin of species?

Most scientists, including Darwin, thought each species was specially created by God in its present form and did not change over time

Allele frequencies can be altered by

Natural Selection Genetic Drift Gene Flow

Crossing over, resulting in an increase in genetic variation, occurs between

Nonsister chromatids of homologous chromosomes

Researchers discovered that female gray tree frogs prefer to mate with males who sound the longest mating calls

Sexual Selection

Genetic variation sources are

Sexual reproduction Mutation

Which observations led to Darwin to establish a relationship between extinct and living animals?

The bony shells of armadillos resembled the shells of ancients Glyptodon fossils The fossilized remains of giant sloths were found in places where smaller sloths now live

The population of American bison used to number in the millions of animals. Hunting and other problems greatly decreased the number of bison to about 1,000 animals. Today, the numbers are recovering to estimates of more than 200,000 animals. This crash in the population of bison and recent recovery is an example of __________.

The bottleneck effect

Which of the following is the most recent example of an evolutionary change in populations?

The development of pesticide-resistant insects

Which of the following is an example of natural selection that has been seen in our lifetime?

The evolution of antibiotic-resistant bacteria

The population of American bison used to number in the millions of animals. Hunting and other problems greatly decreased the number of bison to about 1,000 animals. Today, the numbers are recovering to estimates of more than 200,000 animals. This crash in the population of bison and recent recovery is an example of __________.

2pq

In human gamate production there is an average of crossover events per chromosome pair

2-3

Which of these individuals is a homozygous genotype

AA

Natural Selection results in

Adaptations

Populations may be in

Hardy-Weinbery equilibrium

Observation of natural selection in action

Changes in average size in finches following dry or wet years Development of pesticide resistance in insects

Fossil Record

Discovery of bones from many different dinosaur species Transitional forms that link whales with land-dwelling ancestors that are now extinct

Remember that color is an inherited trait in beetles. Which of the following is an example of natural selection

Green beetles leave more offspring than brown beetles because they are better at finding food

Adaptations to the

Environment

Populations are units that undergo

Evolution

Tristan da Cunha is a remote island in the Alantic Ovean. In 1814, 15 people formed a colony there, one of whom carried a rare gene for blindness. The frequency of this gene is now 10x higher on the island than on the mainland from which the settlers arrived

Founder effect

As habitats change, populations of northern pine trees that were once separated can now exchange pollen. This exchange of genes between populations is allowing the previously isolated gene pools to mix

Gene flow

Insecticide resistance among mesquitoes is spreading around the world after mutations that originate in one population are spread to other populations through matings

Gene flow

Color is an inherited trait in beetles. If brown beetles move into a population from a nearby island, which of the following statements is correct

Gene flow causes the frequency of the brown allele to increase

All the genes in a population are that populations

Gene pool

Populations include individuals with differences due to

Genetic Variation

Modern travel along with migration reduces the probability of _____ having an effect on the evolution of humans

Genetic drift

The evolution of populations due to chance is

Genetic drift

In a population with brown and green alleles for color, genetic drift

Has more effect on the evolution of a small population

If you stop taking antibiotics as soon as you feel better, you may allow

Partially resistant bacteria to survive and multiply

Biogeography

Resembles of island species to nearby mainland species Unique collection of marsupial mammals in Australia

Anatomical and molecular homologies

Same genetic language of DNA and similar genes in yeasts, fruit flies, and humans Similar forelimb anatomy in different species of mammals

To help prevent the proliferation of antibiotic-resistant bacteria, you should

Take the full course of any antibiotics your doctor has prescribes

Darwin and Wallace independently arrived at the same conclusion that species change over time. Which observations supported their conclusion

The bony shells of armadillos resembled fossilized shells from the extinct Glyptodon Tortoises from different Galapagos islands have distinct shells Birdwing butterflies were found throughout the Malay archipelago, but species differed slighlty from island to island. The fossilized remains of giant sloths were similar to the smaller, living sloths Darwin encountered Bird families clustered geographically: cockatoos in the Malay Archipelago and Australia, macaws and hummingbirds in the Americas Mockingbirds from different Galapagos islands had subtle, consistent differences

Imagine that a new population of humans is established on a new planet from ten randomly selected people in your biology class. Over thousands of years, the descendants of those ten people reproduce and prosper, but do not reflect well the diversity of humans on Earth. This change in the diversity of people on the new planet is an example of _____.

The founder effect

If color is an inherited trait in beetles, and birds are more likely to eat brown beetles than green beetles,

The frequency of the green allele will increase

Genetic drift is a process based on

The role of chance

As Wallace traveled the Malay Archipelago, he noticed that western islands had placental mammals, like monkeys. Eastern islands had marsupial mammals, like kangaroos. How did Wallace explain this distribution

The western islands were once connected to Asia and the eastern islands had been connected to Australia. The islands had never been connected to each other

A mutation occurs when

There is a change in the DNA sequence of a gene

Hardy-Weinberg, if no change in

allele frequencies

Evolution, if changed

allele frequency

A process in which organisms with certain inherited characteristics are more likely to survive and reproduce than individuals with other characteristics is called

natural selecion