Some members of a photosynthetic plant species are genetically resistant to an herbicide, while other members of the same species are not resistant to the herbicide. Which combination of events should cause the most effective replacement of the non-herbicide-resistant strain of plants by the resistant strain?

1. The presence of the herbicide in the environment

2. The absence of the herbicide from the environment

3. The maintenance of the proper conditions for one generation

4. The maintenance of the proper conditions for many generations

#Question id: 10671

#Section 2: Evolution

The principle of competitive exclusion states that

#Question id: 12585

#Section 5: Applied Ecology & Evolution

#Question id: 10728

#Section 1: Ecology

Following table shows the number of individuals of different species in two communities, X and Y. Use Jaccard index determine the degree of similarity between X and Y community? 

#Question id: 10676

#Section 1: Ecology

For a pair of interacting species, increased specialization and decreased niche breadth in both species would result in

#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.