Fossils of Thrinaxodon, a species that lived during the Triassic period, have been found in both South Africa and Antarctica. Thrinaxodon had a reptile-like skeleton and laid eggs, but small depressions on the front of its skull suggest it had whiskers and, therefore, fur. Thrinaxodon may have been warm-blooded. The fossils of Thrinaxodon are consistent with the hypothesis that ________.

#Question id: 12264

#Section 1: Ecology

#Question id: 12458

#Section 1: Ecology

#Question id: 9232

#Section 5: Applied Ecology & Evolution

Establishing new nature reserves in biodiversity hot spots may not necessarily the best choice because ________.

#Question id: 10857

#Section 2: Evolution

Cowbirds never make nests, never incubate their eggs, and never care for their young. Instead they lay their eggs in the nests of host species, which either reject the egg or care for it and the young that hatches as their own. The cowbird is an example of a(n)

#Question id: 10655

#Section 2: Evolution

Which of the following statements about the evolution of life histories is correct?

A) Unstable environments with unlimited resources favor r-selected populations.

B) K-selected populations are most often found in environments where density-independent factors are important regulators of population size.

C) Most populations have both r- and K-selected characteristics that vary under different environmental conditions.

D) The reproductive efforts of r-selected populations are directed at producing just a few offspring with good competitive abilities.