Question

all of these are examples of random evolutionary processes except
a.
an earthquake divides a single elk species into two populations, forcing
them to no longer interbreed.

b.
a mutation in a flower plant results in a new variety.

c.
an especially long winter causes a group of migrating birds to shift their
home range.

d.
a mutation results in a population of trees that spread their seeds more
widely than their peers, causing their population to grow.

Explanation:

随机进化过程（如基因漂变、突变、环境随机变化导致的种群改变等）无方向性，而自然选择是定向的。选项A（地震隔离种群）、B（植物随机突变）、C（冬季随机延长改变鸟类分布）都属于随机进化；选项D中树木因种子传播更广（有利变异）而种群增长，是自然选择（定向进化），不属于随机进化过程。

Answer:

D. a mutation results in a population of trees that spread their seeds more widely than their peers, causing their population to grow.