A biologist researched the rate of evolutionary change in a butterfly population on a group of islands over a period of several decades.
He determined that the average length of the proboscis (external mouthpart) of butterflies in a particular population decreased dramatically during a ten year period in which annual rainfall was reduced by 60%.
During that same ten year period, the biologist observed a reduction in the average size of flowers produced by the indigenous plants in the area. In the five years after annual rainfall returned to normal levels, the biologist discovered that the average length of the proboscis increased to the original lengths observed. This reversal in proboscis length can best be explained by which of the following?
A biologist researched the rate of evolutionary change in a butterfly population on a group of islands over a period of several decades.
He determined that the average length of the proboscis (external mouthpart) of butterflies in a particular population decreased dramatically during a ten year period in which annual rainfall was reduced by 60%.
During that same ten year period, the biologist observed a reduction in the average size of flowers produced by the indigenous plants in the area. In the five years after annual rainfall returned to normal levels, the biologist discovered that the average length of the proboscis increased to the original lengths observed. This reversal in proboscis length can best be explained by which of the following?
The correct option is A The end of the ten-year reduction in average rainfall amounts.
It is observed that average length of the proboscis of butterflies decreased dramatically during a ten year period due to reduction in rainfall by 60%. However, the length of proboscis increased to the original length after five years of normal rainfall. The reduction in length of the proboscis was neither related to the food sources nor related to the populations of the predators. This shows, that reversal in proboscis length occurred due to average reducting in the rainfall for 10 years.So, the correct answer is 'The end of the ten-year reduction in average rainfall amounts'
It is observed that average length of the proboscis of butterflies decreased dramatically during a ten year period due to reduction in rainfall by 60%. However, the length of proboscis increased to the original length after five years of normal rainfall. The reduction in length of the proboscis was neither related to the food sources nor related to the populations of the predators. This shows, that reversal in proboscis length occurred due to average reducting in the rainfall for 10 years.
