Question

Using the concept of natural selection, explain how giraffes evolved to have long necks over time. Be sure to write out the 3 steps of natural selection.

Answer 1

Giraffes likely first had short necks and ate the leaves of small trees. As the trees and the ecosystem changed the giraffes were no longer able to reach these trees leaves. The giraffes with short necks then starved and died and the ones with longer necks got to eat and live to reproduce. This eventually led to the tall giraffes we have today.

Answer 2

Giraffes probably used to have short necks. Over time, since the branches of trees or plants were out of their reach, they adapted to this by having a longer neck. Those with longer necks are able to reach the food and eat it that those with short necks could not. Obviously, those with longer necks are able to survive and therefore reproduce. Because of reproduction, they are able to pass on this characteristic that allowed them to survive on to their offspring. This leads to offspring doing the same and over time, affecting the entire population of giraffes and soon evolving giraffes. This is natural selection doing its work in the evolution of long necks in giraffes.

Step-by-step explanation:

Variation. Organisms (within populations) exhibit individual variation in appearance and behavior. These variations may involve body size, hair color, facial markings, voice properties, or number of offspring. On the other hand, some traits show little to no variation among individuals—for example, number of eyes in vertebrates.

Inheritance. Some traits are consistently passed on from parent to offspring. Such traits are heritable, whereas other traits are strongly influenced by environmental conditions and show weak heritability.

High rate of population growth. Most populations have more offspring each year than local resources can support leading to a struggle for resources. Each generation experiences substantial mortality.