Question

1. Which of the following statements about evolution and ecology is TRUE?

Evolutionary processes and ecological processes can occur on similar time scales.

Evolution by natural selection is generally not mediated by ecological phenomena (such as predation).

The evolution of a population will not affect how its members interact with individuals of other species.

Rapid evolution is possible only when a population's chemical environment changes quickly.

2. After common ragweed reached Japan a century ago and escaped their leaf beetle enemies, populations of the plants evolved reduced investment in defense and greater investment in growth. During the last 20 years or so, ragweed leaf beetles have appeared in some parts of mainland Japan. Which of the following scenarios is most likely now happening as a result?

Japanese ragweed is evolving back toward greater investment in defense and reduced investment in growth, as a result of selection by herbivory from beetles.

Japanese ragweed is not evolving a new investment strategy, because it takes more than a couple of decades for a population to evolve.

Japanese ragweed is not evolving a new investment strategy, because the beetles no longer eat the plants.

Japanese ragweed is evolving greater investment in defense and greater investment in growth because both defense and growth are beneficial.

3. Which of the following mechanisms of evolution can act on a single population at the same time?

Only natural selection and genetic drift can happen at the same time.

Genetic drift, migration, and mutation can happen at the same time, but not with natural selection.

Natural selection, genetic drift, migration, and mutation can all happen at the same time.

None of the above. Only one mechanism can act on a population at a time.

Answer 1

Answer 1. :- Rapid evolution is possible only when a population's chemical environment changes quickly.

• Rapid evolution is characterized as genetic change that occurs rapidly enough to have a measurable effect on ecological change at the same time. Following this concept, we suggest a structure for decomposing levels of ecological change into components powered by simultaneous evolutionary change and non- factor change (e.g. density- population dynamics, abiotic change in the environment).

Answer 2. :-  Japanese ragweed is evolving back toward greater investment in defense and reduced investment in growth, as a result of selection by herbivory from beetles.

• Chrysomelidae beetle family insects are generally referred to as leaf beetles, which include more than 37,000 (which possibly at least 50,000) species in more than 2,500 genera, making up one of the largest and most widely found of all beetle families.

Answer 3. :- Natural selection, genetic drift, migration, and mutation can all happen at the same time.

• Natural selection, genetic drift, migration and mutation are processes of evolution that can lead to changes in the frequencies of the alleles. Both of these, at the same time, will operate on a single population.