Many crustaceans (for example, lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of ________.

#Question id: 11715

#Section 1: Ecology

The lifetime dispersal area of a particular species of drosophila is 0.2 km2. What else would we need to know to determine the neighbourhood size for this species?

#Question id: 11254

#Section 1: Ecology

Character displacement:

#Question id: 4708

#Section 2: Evolution

The following questions refer to the figure below, which shows an outcrop of sedimentary rock whose strata are labeled A-D. If x indicates the fossils of two closely related species, neither of which is extinct, then their remains may be found in how many of these strata?

#Question id: 11257

#Section 1: Ecology

Close examination of the yucca-yucca moth mutualism has shown that what appear to be coevolved traits may have been __________ that were critical to the establishment of the mutualism in the first place.

#Question id: 10678

#Section 2: Evolution

In competitive species N1 and N2, four individuals of N2 use the same resource as one individuals of N1. According conversion factor, what is the value of per capita competitive effect of N2 on N1(α) and per capita effect of N1 on N2 ( β) respectively?