Two bird species have different mating calls, occupy different habitats in nature, and when they hybridize, the hybrids are infertile. Which isolating mechanisms maintain these species?
1. mechanical isolation, hybrid sterility, geographical isolation
2. ecological isolation, mechanical isolation, hybrid sterility
3. geographical isolation, temporal isolation, behavioral isolation
4. ecological isolation, behavioral isolation, and hybrid sterility

Which of the following would be an important part of a multi-step plan to restore the stability of the red-cockaded woodpecker's ecosystem?

Number and variety of living organism; includes genetic, species, and ecological types

Cladistics is a way of classifying organisms by examining the characteristics of their ancestors and descendants and depicting the relationships in a cladogram. which of the following best describes a challenge in classifying organisms this way? a. there are millions of species on earth, and a cladogram is not a practical means for classifying all of them. b. it is impossible to tell which organisms are most closely related to each other using a cladogram. c. cladograms are detail-oriented and do not provide a useful understanding of evolutionary relationships. d. there is a limited number of ways to organize the information, so most cladograms end up looking very similar.