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:

• 选项A：地震将单一的麋鹿物种分成两个种群，使其不再杂交，这是由于随机的地理隔离事件导致的，属于随机进化过程。
• 选项B：花植物的突变产生新变种，突变是随机发生的，属于随机进化过程。
• 选项C：特别漫长的冬天导致一群迁徙的鸟类改变家园范围，这是随机的环境变化引起的，属于随机进化过程。
• 选项D：突变导致树木种群比同类更广泛地传播种子，使其种群增长。这是因为该突变带来了适应性优势（更广泛传播种子利于种群增长），是自然选择（非随机过程，自然选择是定向的，保留有利变异、淘汰不利变异）的结果，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.