Question

unit 1 review continued
8 darwins theory of natural selection consists of four important parts. which of
these correctly lists the four essential parts of natural selection?
a living space, adaptation, selection, and learning
b overproduction, genetic variation, selection, and adaptation
c selection, extinction, underproduction, and competition
d asexual reproduction, genetic variation, selection, and adaptation
9 charles darwin studied the finches of the galápagos islands and found that their
beaks vary in shape and size.
darwin found that the finches that ate mostly insects had long, narrow beaks.
finches that ate mostly seeds had shorter, broad beaks to crush seeds. which
statement below best describes how natural selection resulted in the four types
of finches shown above?
a the residents of the galápagos islands selectively bred together finches having
the traits that they wanted them to have.
b the narrow-beaked finches came first and evolved into the broad-beaked
finches through a series of natural mutations.
c the broad-beaked finches wore down their beaks digging for insects and
passed these narrower beaks onto their offspring.
d over time, the finches that were born with beaks better suited to the available
food supply in their habitats survived and reproduced.

Explanation:

• Option A: Incorrect. Darwin's finches' beak variations were due to natural selection, not human - directed selective breeding.
• Option B: Incorrect. The beak variations were not due to one type evolving into another. Natural selection acts on existing genetic variation.
• Option C: Incorrect. Beak shape is a genetic trait, not a trait acquired by wearing down beaks and passed on.
• Option D: Correct. Natural selection favors individuals (finches) with traits (beak shapes) that are better suited to their environment (food supply). These individuals are more likely to survive and reproduce, passing on their advantageous traits.

Answer:

D. Over time, the finches that were born with beaks better suited to the available food supply in their habitats survived and reproduced.