All living species today have passed the “Survival Test” of 4 billion years of evolution. On macro level, each species is the “winner” within its own ecosystem.
For example, the species of alligators you see today are fittest descendants of their ancestors who went through innumerable genetic mutations. Some adapted themselves and living till today and some got extinct.
Scientists claim that Humans and Chimpanzee are descendants of the same ancestor who lived 6 million years ago. So technically speaking, Humans and Chimpanzee are cousins in Tree of Life.
If it is, then who was our father ancestor? What split Humans and Chimpanzee?
DNA and Mutations
The bio cells in our body keep making copies of itself in order to survive. In process of copying, the base pair of DNA changes which we call “Point Mutation”. This mutation is transferred in descendants if it happens in “Germ Cells”. The offspring born this way is slightly different from its parents. This mutation bring in major physical and cognitive changes in millions of years.
Apart from mutation, DNA gets more options to bio-diversify itself when two organisms get into a physical intercourse. The physical change also happens when a cell has an abnormal number of chromosomes, either more or fewer than the typical number.
If we put two groups of same species in different Geographical conditions for a long period of time, there would be distinct changes in their DNA through Gene swapping, mutations and Chromosomes fusion. If the separation of groups in for millions of years, the changes would be so concrete that they are wouldn’t be able to cross-reproduce on mating. At this point, we can say that these are two different species.
Evolution has followed the same principal for 4 billion years in achieving this bio-diversity.
Visible Changes in Organisms
Every living organism is made of DNA. When a bio cell copies itself, its passes on the DNA into the new one. However, evolution is not a “perfect” process and bio cells may copy DNA erroneously while replicating itself.
The fur on the body of Pomeranian dog is developed just by a single point mutation in their FGFS gene.
In humans, the Factor 10 gene plays a crucial role in the blood clotting process. This gene produces a protein called Factor X, which is essential in formation of blood clots to stop bleeding. However, in snakes, a single genetic mutation in the Factor 10 gene has led to a significant adaptation. This mutation produced an altered form of the Factor X protein, which has a different function compared to its role in humans. In snakes, this protein enabled snakes to kill their prey through venomous bite.
Humans (Or we call Homo Sapiens) is a result of genetic mutation of human-like ancestor Homo Heidelbergensis. It’s believed that Homo Neanderthals is also its descendent.
Homo heidelbergensis had large brain size (As if you are wearing a helmet), small jaw and teeth. They existed about 700,000 to 300,000 years ago. So, I am taking a median period of 500,000 years after which Homo Sapiens show significant mutation in their physical and cognitive properties.
Back To The Future
After 2 or 3 million years, the humans would be totally transformed into another species we can’t think of. Our future generations may look like aliens which are shown in sci-fi movies. Not only humans, all other living beings (animals and plants) are also evolving continuously at different speed. May be our descendants would study in their History subject how present-day Dinosaurs evolved from their ancestor, Giraffe. How genetic mutations in today’s Lizards transformed them into future dragons.
Whatever it will be, one thing is certain. Homos will stay atop food chain and witness themselves and other living species evolve (Unless they kill themselves in nuclear war or some natural calamity wipe them off from earth).
Co-Author: Harshita Sharma is PhD in Molecular Biology and a Research Scientist at RIKEN Center for Integrative Medical Sciences, Yokohama, Japan.
