Bell and collaborators painstakingly documented a population of fossil sticklebacks from an ancient freshwater lake over a 20,000-year period. The prevalence of sticklebacks with full and reduced pelvises changed over time. Which is true?
a. In this population, having pelvic spines seemed to provide a selective advantage to stickleback fish.
b. The population of fish with pelvic spines that arrived in the lake at time B evolved a reduced pelvis over time (beginning at time C).
c. By the end of the studied period (time D) there was an approximately equal number of sticklebacks with and without spines. Initially (time A), fish with full pelvises dominated the lake population. d. The evolution of pelvic reduction seen in the fossil record is different from the phenomenon occurring in the lakes in Alaska today.

The population of fish with pelvic spines that arrived in the lake at time B evolved a reduced pelvis over time (beginning at time C).

Explanation:

The fossil record showed that before the time period B, the ancient sticklebacks might have had a huge pelvis which was of no use to them. As a result, through evolution at time B the pelvis reduced in the sticklebacks through natural selection. Having a reduced pelvis must have been advantageous for this ancient stickleback population, just as it is for many current freshwater stickleback populations. Hence, the correct option is B.

succession returns a disturbed

ecosystem to a more stable state. this is also classified into two (2) types:

primary succession and secondary succession. the primary succession arises when

a new land is transformed and a bare rock has been exposed providing an environment

that can be occupied for the first time. while, secondary succession occurs

when a previously occupied environment was disturbed that kills much of all its

community

explanation: