Section 15.1

The development of new types of organisms from preexisting types of organisms over time.

• Evolution
• Natural Selection

Process in which organisms best suited to their environment reproduce more successfully than other organisms.

• Evolution
• Natural Selection

 If Lamarck’s hypothesis of species modification were true, the children of a person who developed large muscles by lifting weights would be born with

• smaller-than-average muscles.
• normal-sized muscles.
• normal-sized muscles that would become larger only if the children also lifted weights.
• larger-than-average muscles

What is the idea developed by Charles Lyell stating that the geologic processes that shaped Earth in the past continue to operate today?

• inheritance of acquired characteristics
• catastrophism
• uniformitarianism
• descent with modification

Darwin used the phrase “descent with modification” to mean that

• new species descended from preexisting species, and species must be able to change over time.
• organisms that descend from high elevations are modified as they acquire new traits.
• all living things descended from a recent common ancestor on the Galápagos Islands.
• individuals modify their behavior to survive and then pass those modifications on to their descendants.

According to Darwin’s theory of natural selection,

• individuals are modified by adverse environmental conditions.
• the environment affects all organisms in a population in the same way.
• populations of all organisms grow unchecked under natural conditions.
• organisms that have more favorable traits tend to leave more offspring.

In an evolutionary sense, an individual organism has high fitness if it

• has a large number of acquired traits.
• can run long distances without becoming exhausted.
• reproduces more successfully than other individuals.
• evolves into another organism rather than becoming extinct.

Why are acquired traits not directly related to the process of evolution?

• Since acquired traits are not genetically determined, they cannot be passed on to offspring. 
• they cannot cause a population to change over generations.
• Both

Darwin extended Malthus’ ideas to populations of all organisms and reasoned that the environment limits the populations of all organisms by causing deaths or limiting births.

• True
• False

Evolution is the change of populations of organisms over time; natural selection is the mechanism by which evolution occurs.

• True
• False