Human Evolution

Natural Selection and Human Evolution

Natural Selection and Evolution Assignment

The process of natural selection gives us an account of how life has evolved.

All life began in the ocean as simplistic cells that had yet to evolve. Everything alive today has a single cell as its ancestor, which over many millennia formed into the organisms here today, that are still adapting and changing to accommodate their habitat into their life.

Natural Selection is a vital process for Evolution. This process has been around since the beginning of planet earth. Without it, everything on this planet would have stayed as simplistic creatures that would have ended up extinct as they couldn't adapt to their ever-changing environment.

Charles Darwin once said that for Natural Selection to occur, three conditions must be met. The first one is existence; the second condition is variation and the third is inheritance.

Within species, more offspring are produced by 'parents' who can survive constraints in their respective environment, e.g, food supply (among other things).

This is what scientists call survival of the fittest, which leads to natural selection.

Expanding on the three mandatory conditions that must be met:

As a result of certain constraints, there is a struggle for existence. This is a direct result of survival of the fittest because generally, only organisms that are alive can reproduce.

Within a species, every individual accommodates variation. This indicates that no two individuals are completely identical (identical twins even show variation, and they grew from the same egg at the same time). A species has the same base characteristics but are still individual. This means that say, one out of two in a species is more adapted to surviving and therefore have a greater chance of reproducing. The one individual with less adapted traits struggle for existence.

As time goes on, more traits are passed down from the survivors of the species to their progeny. This is the inheritance principle. However, this is provided that the genes that give that species an advantage get inherited by the progeny. As time continues to pass, these survival characteristics become more and more common over generations.

Every time Natural Selection occurs, there are advantages and disadvantages that either further evolve to aid the organism or it can ultimately be difficult to exist with, so it learns to incorporate it into its life or be lost in generations.

The Evolution of Homo Sapiens.

Every living thing began in the ocean, so organisms had to evolve to transfer to the land.

Many people believe that we, as a species, evolved straight from current simians, and particularly, the chimp. While this is somewhat true, it is still a common misconception.

So, what happened?

Over time, every species today branched out from the first organism called cyanobacteria to prokaryote. These organisms continued evolving until one branch called Hominidae were formed, and we reached our common Ape Ancestor which we share with simians today. From that Ape Ancestor, two species branched out. They are related but separate. One branch split into simians and the other, early forms of hominin.

The earliest humanoid fossil found thus far, is the Sahelanthropus Tchadensis (Chad) who lived in the Miocene epoch.

Paleontologists are still searching for more pieces of his skeleton and older fossils, but from the six fossils that have been collected, a few theories are being tossed around.

Chads' species existed approximately 6-7 million years ago He was found in Chad, West-Central Africa... hence the name, Chad.

Chad had both human and chimp traits. He had small canine teeth. Nevertheless, he had mostly chimp like characteristics such as a sloping and elongated skull, prominent brow ridges, a short middle section of the face, but also had a smaller brain than a present-day chimp. Chad had small, flat canine teeth which was unusual for a male primate.