The treeʹs horizontal axis is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V—Z) represent various common ancestors. Letʹs say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.

Which of the five common ancestors, labeled V—Z, has given rise to the greatest number of species, both extant and extinct?

#Question id: 12295

#Section 1: Ecology

#Question id: 11354

#Section 4: Behavioural Ecology

C.B. Huffaker was able to maintain experimental populations of predator and prey (using species of mites) that exhibited recurring oscillations. What feature of Huffaker's experimental design was critical to this outcome?

#Question id: 10752

#Section 2: Evolution

Which of the following is an example of Batesian mimicry?

A) a butterfly that resembles a leaf

B) a nonvenomous larva of a moth that moves like a venomous snake

C) a fawn with fur coloring that camouflages it in the forest environment

D) a snapping turtle that uses its tongue to mimic a worm, thus attracting fish

#Question id: 16869

#General Aptitude

#Question id: 4652

#Section 2: Evolution

The graph depicts four possible patterns for the abundance of 3TC-resistant HIV within an infected human over time. If 3TC resistance is costly for HIV, then which plot (I—IV) best represents the response of a strain of 3TC-resistant HIV over time, if 3TC administration begins at the time indicated by the arrow?