In the Next 20 Years

question 94

Multiple Choice

In the next 20 years,

• A) there should be a continuous increase in the U.S. birthrate.
• B) the population of the U.S. will probably decline unless immigration offsets low birthrates.
• C) the growth rate of the U.S. population will rise.
• D) the U.S. population is expected to double.
• E) population will increase at a faster rate in the U.S. than in the rest of the world.

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Definitions:

Geographic Isolation

A situation where a population of species is physically separated from exchanging genetic material with other populations due to geographical barriers, leading to divergent evolution.

Reproductive Isolation

A set of mechanisms that prevent members of different species from producing offspring, or ensure that any offspring are sterile, thereby maintaining species boundaries.

Transgenic Organism

An organism that has been genetically modified to contain DNA from another species, allowing it to express traits not originally found in its genome.

Background Extinction

The natural rate at which species become extinct as part of earth's biological history, without human influence.