For two species A and B in competition, the carrying capacities, competition coefficients, per capita growth rate and population size are

KA = 1000          KB = 1200        α= .5    r A= .3    N1= 500         N2= 200          

According to the Lotka-Volterra model, what is growth rate of species A?

#Question id: 4643

#Section 2: Evolution

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.

How many separate species, both extant and extinct, are depicted in this tree?

#Question id: 12444

#Section 1: Ecology

#Question id: 3430

#Section 2: Evolution

The proximate causes of behavior are interactions with the environment, but behavior is ultimately shaped by

#Question id: 3483

#Section 2: Evolution

Which of the following statements about evolution of behavior is correct?

A) Natural selection will favor behavior that enhances survival and reproduction.

B) An animal may show behavior that maximizes reproductive fitness.

C) If a behavior is less than optimal, it is not completely evolved but will eventually,become optimal.

#Question id: 3275

#Section 2: Evolution

When imbalances occur in the sex ratio of sexual species that have two sexes (that is, other than a 50:50 ratio), the members of the minority sex often receive a greater proportion of care and resources from parents than do the offspring of the majority sex. This is most clearly an example of ________.