Question

Question 11

The wings of birds have evolved to facilitate powered flight, but they are also:

Derived from structures that had other functions, such as thermoregulation and sexual display.

Able to evolve into any other type of structure, given the flexibility of developmental genes.

Unable to revert back to serving other functions (if they ever had them).

Certainly only a transition on the way to something else in the future.

Question 12

Which of the following is TRUE:

For most of life's history, organisms have been multicellular, though hominids only occupy a tiny portion of this history.

For most of life's history, organisms have been a mixture of uni- and multicellular, through hominids have occupied only a fairly small portion of this history.

For most of life's history, organisms have been unicellular, and hominids occupy only a tiny portion of the entire span of time in which life has existed on Earth.

For most of life's history, organisms have reverted back and forth between uni- and multicellular, with a sort of "zig-zag" pattern in which one form of life dominated at any particular time.

Question 13

There are some phenotypic differences among human populations that reflect adaptation to different environments. This indicates that:

Some populations are innately superior to others, because they have what it takes to prevail in those environments.

Selection has been active on these populations.

There are candidates for a program of selective breeding wherein we can pinpoint universally desirable characteristics.

Admixture among human populations is decreasing, and that continued admixture can only mean that humans must stop adapting to their environments. This is neither "good" or "bad", it's simply the way that selection works.