This would most likely be an example of directional

This preview shows page 2 - 5 out of 9 pages.

This would most likely be an example of directional selection, where the population that survived the first event had traits (hypoxia tolerance in this case) that were on the extreme of the range of tolerances for the original population. It would be most like the example of the swallows discussed in Figure 25.3. Question 5 Evolution is the term that describes only the origin of species. False
Hide Feedback
False. Evolution is a process by which lineages of organisms change. The origin of species is part of the evolutionary process, but there are other aspects as well. Evolution can occur without new species arising. Question 6 For evolutionary trees, a "node" is a point in a tree, from which two or more "branches" emerge, eventually leading to "tips" representing a single group.
Hide Feedback True. All true. Get comfortable with the terminology. Question 7 Gene flow between two populations of a species usually impedes speciation.
Hide Feedback True. If the two populations interbreed, the intermingling of genes prevents each population from diverging from the other. Question 8 Hardy-Weinberg equilibrium arises only when random mating and several other conditions apply within a population.
Hide Feedback True. Think of it as the result of nothing special happening in the population. For this reason, it is considered the null hypothesis. Departures from Hardy-Weinberg equilibrium indicate that something is happening (e.g. gene flow, natural selection, mutation, etc) in the population (and the null hypothesis is rejected). Question 9 Ichthyosaurs and dolphins share similarities only because mammals and reptiles shared a common ancestor. True False
Hide Feedback False. Some traits are similar because of shared ancestry, but other "analogous" traits are similar because of convergent evolution. Evolution led to similar solutions to the common problems related to their similar ecological niches. The common ancestor of ichthyosaurs and dolphins looked nothing like either one.

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture