Question

With the help of a suitable example explain the role of humans in the process of natural selection

Answer 1

In an ecosystem, some giraffes have long necks and others have short ones. If something caused low-lying shrubs to die out, the giraffes with short necks would not get enough food. After a few generations, all the giraffes would have long necks.
A species of rats live in a certain type of tree with the branches evenly spaced. Smaller rats could not reach from branch to branch and larger rats would break the branches and fall. Soon, all rats were just the right size for the tree branches.
Deer mice that migrated to the sand hills of Nebraska changed from dark brown to light brown to better hide from predators in the sand.
Galapagos finches all have different types of beaks. During drought, the finches with the larger beaks survived better than those with smaller beaks. During rainy times, more small seeds were produced and the finches with smaller beaks fared better.
In one ecosystem, lizards that had long legs could climb better to avoid floods and reach food.
Insects become resistant to pesticides very quickly, sometime in one generation. If an insect is resistant to the chemical, most of the offspring will also be resistant. Considering that insect generations can be a matter of weeks, insects in an area can become immune to a chemical within months.
The bacterium Pseudomonas metabolizes nylon; but, when a certain type of this bacterium that did not eat nylon was placed in an environment where nylon was the only food, the bacterium evolved until it ate the nylon.
Peacock females pick their mate according to the male’s tail. The ones with the largest and brightest tails mate more often. Today, males that do not have bright feathers are very rare.

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