Question

Which of the following statements accurately describes the results of Velicer and Lenski's experiments on swarming behavior in Myxococcus xanthus?

(A) M. xanthus evolved to be faster in the high density treatment and slower in the low density treatment
(B) M. xanthus evolved to be faster in both treatments, but the low density treatment became faster than the high density treatment
(C) M. xanthus evolved to be faster in the low density treatment and slower in the high density treatment
(D) Swarming behavior did not change in either treatment

Answer 1

The exact outcomes of Velicer and Lenski's experiments on M. xanthus swarming behavior are not described in the provided information, but such experiments typically involve imposing selection pressures, leading to changes such as multicellularity or altered swarming speed in organisms.

Step-by-step explanation:

The experiments conducted by Velicer and Lenski on the swarming behavior in Myxococcus xanthus are a classic example of directed evolution where investigators impose selection pressures and observe the evolution of a population.

According to the information provided, there is no specific result given directly correlating to the options (A) through (D) regarding the exact outcomes of Velicer and Lenski's experiments on swarming behavior in M. xanthus.

Therefore, based on the given context, we can infer that the experiments involved selection pressures that might lead to the evolution of certain traits, such as multicellularity or swarming speed, depending on the conditions like the density of nutritional resources or sedimentation in a column of nutrient-containing solution.

These experiments underline the concept that evolution is a response to environmental pressures and that cooperative behavior may have advantageous or disadvantageous effects, depending on the conditions. In laboratory settings, similar pressures have been shown to influence characteristics such as multicellularity in yeast and genetic variation in voles.