Bio Ch 14

Feathers either play a role, or may have played a role, in _____.

all of these

_____ is rapid speciation under conditions in which there is little competition.

Adaptive radiation

Mass extinctions create conditions that promote _____.

adaptive radiation

The appearance of an evolutionary novelty promotes _____.

adaptive radiation

The different finch species found on the Galápagos Islands probably arose as a result of _____.

adaptive radiation

In _____ isolation, it is physically impossible for two species to mate with each other, often because their genitalia do not fit together properly.

mechanical

Eastern and western spotted skunks breed at different times of the year. Therefore, they are prevented from interbreeding by _____ isolation.

temporal

Speciation, or the formation of new species, is

responsible for the diversity of life.

Which of the following would a biologist describe as microevolution?

a change in the gene pool of a population from one generation to the next

Under the biological species concept, a species is a group of organisms that

have the potential to interbreed in nature and produce fertile offspring.

The biological species concept is

sometimes difficult to put into practice even for present sexual organisms, and useless for asexual organisms and fossils.

Which of the following statements regarding the definition of species is false?

The morphological species concept relies upon comparing the DNA sequences of organisms.

Which provides the most general and correct description of the idea of a reproductive barrier?

a biological difference between two species that prevents them from successfully interbreeding

Two populations of organisms belong to the same biological species when they

encounter each other, mate, and produce viable, fertile offspring under natural conditions.

Which of the following types of reproductive barriers separates a pair of species that could interbreed except that one mates at dusk and the other at dawn?

temporal isolation

Which of the following types of reproductive barriers separates a pair of insect species that could interbreed except that one lives on goldenrod plants and the other on autumn daisies in the same general area?

habitat isolation

Which of the following types of reproductive barriers separates a pair of moth species that could interbreed except that the females’ mating pheromones are not attractive to the males of the other species?

behavioral isolation

Which of the following types of reproductive barriers separates two flowering plant species that could interbreed except that one has a deep flower tube and is pollinated by bumblebees, whereas the other has a short, narrow flower tube and is pollinated by honeybees?

mechanical isolation

Which of the following types of reproductive barriers separates two species of sea cucumbers, whose sperm and eggs often bump into each other but do not cross-fertilize because of incompatible proteins on their surfaces?

gametic isolation

Two species that occasionally mate and produce zygotes, but which have incompatible genes that prevent the resulting embryo from developing, are separated by

reduced hybrid viability.

Two species that sometimes mate and produce vigorous but sterile offspring are separated by

reduced hybrid fertility.

Two species interbreed occasionally and produce vigorous, fertile hybrids. When the hybrids breed with each other or with either parent species, however, the offspring are feeble or sterile. These species are separated by

hybrid breakdown.

Frequently, a group of related species will each have a unique courtship ritual that must be performed correctly for both partners to be willing to mate. Such a ritual constitutes a ________, ________ reproductive barrier.

behavioral . . . prezygotic

The Monterey pine and the Bishop’s pine inhabit some of the same areas of central California. The Monterey pine releases pollen in February, while the Bishop’s pine does so in April. This is an example of ________ isolation.

temporal

In 2004, scientists announced the discovery of the fossil remains of some extremely short early humans on the Indonesian island of Flores. The new species has been named Homo floresiensis. One hypothesis is that H. floresiensis evolved from Homo erectus, another early human species. How did a population of H. erectus become isolated on this remote island? Early humans constructed boats and rafts, so perhaps they were blown far off course by strong winds during a storm.

H. erectus averaged almost 6 feet in height, but the remains show that adults of H. floresiensis were only about 3 feet tall. It’s hypothesized that limited resources on this hot and humid island (only 31 square miles) exerted selection pressure and succeeding generations began to shrink in size. Small bodies require less food, use less energy, and are easier to cool than larger bodies. Evolution of small size in similar circumstances has been observed in many other species, but never before in humans. This find demonstrates that evolutionary forces operate on humans in the same way as on all other organisms.

The evolution of Homo floresiensis is an example of

allopatric speciation

The geographic isolation of a population from other members of the species and the subsequent evolution of reproductive barriers between it and the parent species describes ________ speciation.

allopatric

Uplift and formation of a mountain range divides a freshwater snail species into two isolated populations. Erosion eventually lowers the mountain range and brings the two populations together again, but when they mate, the resulting hybrids all produce sterile young. This scenario is an example of

allopatric speciation

In which of the following situations would speciation be most likely to occur?

Seven monkeys escape from an amusement park and zoo in South Florida. To everyone’s surprise, they establish a small but viable population, coexisting successfully with humans in a partly suburban environment very different from their native African habitat.

If H. floresiensis were reunited with H. erectus at a much later date, but the two populations could no longer interbreed, it would be correct to conclude that H. floresiensis

had evolved reproductive barriers.

Diane Dodd raised different fruit fly populations on different food sources. She found that after about 40 generations, the evolution of reproductive isolation was under way. The mechanism of evolution responsible for this was

natural selection.

Humans are diploid and have 46 chromosomes (or two sets). How many sets of chromosomes are found in each human gamete?

1

Humans are diploid and have 46 chromosomes. How many chromosomes are found in each human gamete?

23

_____ is the process by which haploid gametes form a diploid zygote.

Fertilization

A particular diploid plant species has 48 chromosomes, or two sets. A mutation occurs and gametes with 48 chromosomes are produced. If self-fertilization occurs, the zygote will have _____ set(s) of chromosomes.

4

Which of these terms applies to an organism with extra sets of chromosomes?

polyploid

Mutant tetraploid plants _____.

are unable to interbreed with a diploid plant

Most polyploid plants arise as a result of _____.

hybridization

Speciation without geographic isolation is called ________ speciation.

sympatric

Organisms that possess more than two complete sets of chromosomes are said to be

polyploid

When a tetraploid flower pollinates a diploid flower of the parental species, the resulting offspring will be

triploid and sterile.

Sympatric speciation commonly occurs through ________ in plants, but is more likely to occur through ________ in animals.

polyploidy . . . habitat differentiation and sexual selection

The emergence of many diverse species from a common ancestor is called

adaptive radiation.

Which of the following would tend to promote adaptive radiation?

An organism colonizes an isolated area that is habitable but relatively devoid of life

Two bird species overlap in a hybrid zone. They are isolated by a slight difference in the male songs and by the females’ tendency to select males with the "correct" song. Hybrid offspring tend to have reduced fertility compared to either of the parent species. What effect might natural selection have in this situation?

Natural selection might favor males with more distinctive calls and/or females that are more "choosy." As a result, the reproductive barrier between the two species could be reinforced.

The ________ suggests that speciation occurs in brief spurts

punctuated equilibrium model

The emergence of a new plant species over a brief period of time, followed by a long period of little change, is consistent with which of the following theories?

punctuated equilibrium

Which of the following descriptions best represents the gradual model of speciation?

Speciation occurs regularly as a result of the accumulation of many small changes.

One of the finest available sequences of fossils shows how horses have changed slowly and by subtle steps from small shrub-browsing ancestors to the large, grass-grazing modern horse. A large number of fossil species have been named, and it is often difficult to decide on the identity of a fossil horse because transitional forms are common. This record of evolution best fits the idea of

the gradual model of speciation

The fossil record shows that for many plant and animal groups, the time between speciation events

varies greatly, but averages 6.5 million years.

How are refined sugar and high fructose corn syrup different?

High fructose corn syrup contains more fructose than refined sugar.

What, in part, fueled the use of high fructose corn syrup?

High fructose corn syrup is cheaper to produce than refined sugar.

Which organ converts fructose to fat?

liver

Approximately how much sugar does the average American consume each year?

90 pounds

Which of the following is in the correct order leading to the development of heart disease?

fat accumulation, insulin resistance, metabolic syndrome