Guest Author - Alegra Bartzat

As long as humans have studied nature, we have been able to observe how perfectly the world fits together. Some birds eat nuts and seeds, and they have beaks made for eating nuts and seeds. Some birds eat worms and insects from the ground, and their beaks work well for that kind of hunting. Other birds prey on small animals, and they have both razor sharp beaks as well as talons. The list goes on an on. Wild cats have flesh tearing teeth and short digestive tracts for eating raw meat. Giraffes can reach the leaves on very tall savannah trees. All of these perfect puzzle pieces fit together because plants and animals evolve over time, growing into their niche in the environment.

It was Charles Darwin and the Galapagos finches that led us to the theory of evolution that would eventually gather enough evidence to be considered fact. It was, of course, revolutionary at the time. The special environment of the archipelago of islands in the Galapagos allowed Darwin to observe many types of finches that very likely had evolved from a single species that had made it to these islands form the South American mainland.

Fossil records have allowed to us to further support Darwin’s evolution. The evolution of elephants has been very well tracked. There are five different groups of animals that have eventually morphed enough to warrant a changed species identity. Early proboscideans were much smaller than today’s elephants, without the long trunk and tusks we associate with elephants. However, by following the fossil record, we can see the pattern emerge of a growing body as well as an elongating trunk and tusk that, over a course of 50 million years, leads us to the elephant we know.

How do these changes occur? Any given animal will typically bear young, but not all those young will make it to adulthood to bear young of their own. The characteristics that make a plant or animal more likely to reproduce will be carried on, while characteristics represented in those who did not reproduce will not be carried on. So, if a long tusk was attractive to females, it will be carried on. If a long tusk allows an elephant to defend itself against predators, again it will be carried on. The animals with shorter tusks were less likely to survive and reproduce, so the characteristic of a shorter tusk eventually disappeared from the gene pool.