Mastering Biology Chapter 14

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

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

Mass extinctions create conditions that promote _____.

The appearance of an evolutionary novelty promotes _____.

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

Classifying Reproductive Barriers:

According to the ______ species concept, a species is a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring.

The separation between species is maintained by _______ isolation, which prevents gene flow between species.

But in some cases, distinct species can occasionally interbreed, producing ________ offspring.

Alternatively, the _______ species concept identifies species based on physical traits or body form.

This species concept can be applied to ________ species, and it is the way most of the 1.8 million named species have been identified.

In the _______ species concept, species are defined by their niche--the role they play in the environment.

The ________ species concept defines species as the smallest group of individuals that share a common ancestor and form one branch on the tree of life.

In ________, a population isolated by a geographic barrier becomes a new species as it accumulates changes by natural selection or genetic drift.

In ________, a new species may arise as mating and gene flow are reduced between populations that share the same area.

Many plant species have formed by _______, in which accidents in cell division result in extra sets of chromosomes.

Both allopatric speciation and sympatric speciation depend on the establishment of ________, which prevent(s) gene flow between a new species and its parent species.

________ occur(s) when a species gives rise to many new species after colonizing a region with diverse habitats.

Connecting the Concepts: Species and Speciation:

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

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

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

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.

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

Mutant tetraploid plants _____.

Most polyploid plants arise as a result of _____.

How do the skulls of adult chimpanzees and humans differ?

The differences between chimpanzee and human observed in these animations is attributable to differences in ____.

What accounts for human infants having large heads on small bodies?

Variations in allometric growth patterns demonstrate how _____.

Which of these is a difference between the skull of an adult chimpanzee and the skull of an adult human?

Which of the following statements about reinforcement is true?

A subset of a population of birds leaves its habitat and colonizes a nearby island. After many generations, the island sinks and the population of birds living on the island returns to its original habitat. Which of the following statements most accurately describes the two bird populations?

A biologist spends her summer break collecting frogs from a remote jungle in Peru. She discovers two distinct color forms that could be variants of a single species or two different species. What would be the most direct test of their species status under the biological species concept?

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

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

The process of speciation starts with a single species. It often involves the following steps: (1) two populations become physically separated from one another by a barrier to dispersal and stop exchanging genes; (2) the populations experience independent evolutionary changes; (3) changes in one or both populations result in the development of reproductive isolating mechanisms that prevent interbreeding; further changes in geography may bring the groups back into contact. When do you officially have two separate species?

Darwin thought that significant evolution was much too slow to be witnessed in a human lifetime. Recent experiments by biologists have _____.

Of the 59 matings in the experimental groups, how many were between like-adapted flies (flies adapted to the same medium)?

Which of the following statements is best supported by the data on matings in the experimental groups?

Which of the following statements is supported by the data from the control group matings?

A similar control experiment was performed with flies adapted to maltose, and similar results were obtained. What were these control experiments testing?

Current best estimates suggest that life has been on Earth for how long?

If life exists or originated on another planet, most scientists today believe that it is which of the following planets?

Which of the following is true regarding current scientific thought?

You discover a new means of energy transfer by organisms living in hydrothermal vents in the ocean. Who is most likely to be interested in funding your research?

Which of the following scientists is closest to creating life?

According to most paleoanthropologists, which of the following is true?

If your pituitary gland isn't functioning properly, which of the following will be affected?

You are a paleoanthropologist studying Neanderthals. Where should you look for their fossils?

What do paleoanthropologists generally believe about genetic findings?

How do genomes of species change?