Ch 13 and 14

prezygotic barriers

-Behavioral isolation: two species of birds sing different mating songs -mechanical: two flower species have shapes that fit different insect pollinators -habitat isolation: different ticks live on different host species -temporal isolation:two short lived mayfly species hatch during different weeks -gametic isolation : one sea urchins sperm cannot fertilize another species eggs

The evolution of populations due to chance is

genetic drift

The phrase Darwin used to describe his broad theory of evolution is ''descent with __________.''

modification

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

All of life is related through common ancestry, accounting for the ______ of life.

unity

This unequal reproduction in a population leads to the gradual accumulation of __________ to the environment.

Adaptions

In a species of snail, dark-shelled individuals are better hidden from bird predators in the shady forest, while light-shelled individuals are better hidden in well-lit brushy edge areas. If there were no areas of intermediate brightness in this habitat,which type of selection would act on shell color in these snails?

Disruptive selection

Examine the two squirrel populations in the following figure. The populations are separated by a geographic barrier. If after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred?

The two populations are not interbreeding freely.

Natural selection generally results in _______

a population that is adapted to its current environment

Natural selection can be defined as ________.

a process in which organisms with certain inherited traits are more likely to survive and reproduce than individuals with other traits

What accounts for the different breeds of domesticated dogs?

artificial selection

What type of reproductive isolating mechanism is described by a situation in which female fireflies mate only with males who emit light in a particular pattern?

behavioral isolation

Under the biological species concept, what criterion is used to assign populations of organisms to the same biological species?

being able to interbreed and produce fertile offspring

Which of the following is NOT a requirement of natural selection?

catastrophy

The similarity of the embryos of fish, frogs, birds, and humans is evidence of ________.

common ancestry

A challenge to traditional (pre-1860) ideas about species came from embryology, where it was discovered that __________.

embryos of dissimilar organisms, such as sharks and humans, resemble each other

Which mechanism for evolution was proposed by Lamarck?

evolution by inheritance of acquired characteristics

Which of the following is the most likely explanation for a particular human population with a higher incidence of polydactyly (extra fingers/toes) than the human population as a whole?

founder effect

Which of the following is NOT a requirement of natural selection?

gene flow due to migration of new individuals into the population

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

has more effect on the evolution of a small population.

In his book The Origin of Species, Darwin argued that species living today descended from a succession of ancestral species. What mechanism did Darwin propose to explain how evolution occurs? View Available Hint(s)

natural selection

The _________ of life arises from the adaptation of species to different habitats over long spans of time.

Diversity

What mechanism explains why polar bears are white and bears found farther south have a darker color?

natural selection

About 40 years ago, Peter and Rosemary Grant measured changes in the beak size of a population of Galápagos ground finches. This ________.

provided evidence of natural selection in action

Over a span of two decades, scientists measured changes in the beak size of a population of Galápagos ground finches. This ________.

provided evidence of natural selection in action

postzygotic barriers

reduced hybrid viability, reduced hybrid fertility, hybrid breakdown

What does evolutionary fitness measure?

relative reproductive success

Which of the following statements about the voyage of the Beagle is TRUE?

It turned into a tremendous opportunity for Darwin to collect fossils, plants, and animals.

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.

. Darwin proposed a mechanism for how evolution occurs, which he called ______

Natural selection

Which one of the following statements is TRUE

Natural selection works on variation already present in a population.

Darwin inferred that those organisms with traits best suited to the environment tend to leave more ________ than other members of a population.

Offspring

Small lizards have difficulty defending their territory, but large lizards are more likely to be preyed upon by owls. Which type of selection would act on body size in these lizards under these conditions?

Stabilizing selection

Natural selection ________.

results in evolutionary adaptation

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.

Which of these scenarios is the result of natural selection?

the proliferation of pesticide-resistant insects

After surviving a bottleneck, a population recovers to the point where it consists of as many individuals as it did prior to the bottleneck. Which of the following statements is most likely to apply to this population?

The postbottleneck population exhibits less genetic variation than the prebottleneck population.

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

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

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

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

Which of these is required for natural selection to occur?

-unequal reproductive success -inheritance -individual variation

The wing of a bat is homologous to the _____ of a whale.

Flipper

Two key observations underlying natural selection are that members of a population vary in their ______________ and that all species can produce more offspring than the environment can support.

Inherited traits

Which of these is an example of temporal isolation

One species is nocturnal, and the other species is diurnal (active during the day).