Three million years back; a rigid looking hairy quadruped was perched on a dry, lonely tree. His arms were stronger than his legs but under his weight, the tree which was the only one of its kind for miles in the grass filled savannah began to creak and squeal. The quadruped had jet black hair all over his body expect for around his lips, eyes, palms and soles of the feet. He looked wearily in every direction and sleepily came back to the ground to join his family.
Let us call this organism as Mr.X; simply because ‘Rohit’ or ‘Ramesh’ would sound silly for such a hairy quadruped. Being the head of the family he scanned the area for intruders. The young males scrambled around looking afraid of him and the females were busy preening their newborns.
Within 10 seconds under the scorching heat of the savannah, Mr.X heard a high pitched squeal; then a laughter. It sounded more like a snort; like when an insecure person would tell a joke and would laugh at himself. That Mr.X knew to be the sound of a dangerous animal. Hyenas.
Mr.X’s family was agitated as the tall grass blocked their view and they couldn’t see or sense from which direction the sounds were coming from. Hyenas hunt in packs and they tend to narrow in onto a target from as many directions as possible. However as Mr.X’s tiny brain raced for an escape route, something seemingly simple yet utterly important happened.
Mr.X has a genetic gift. His leg bones – are not as arched back as his ancestors on his pelvic girdle and hence it was quite flexible. His pelvis was stronger. Mr.X lifted his hands from the ground and stood on two legs. A quadruped became a biped. An animal which walked on four legs could now stand on two. He was looking for hyenas.
He saw them approaching. Six of them zeroing in from north and west whereas the south was clear of them. He immediately returned back to his position of standing on four legs and chased the females away towards south. He then ran along with them to safety. The hyenas returned without food. Mr.X and his family lived another day. To eat, to breed and to eventually become modern humans.
Human evolution is an interesting mystery which is slowly solved by many scientists acting like the various brain sections of Sherlock Holmes on a piece of puzzle. Collecting data and extrapolating them. The Bottoms up approach it is called. From the fossil records, it was quite clear that we shared a common ancestor with chimpanzees ( We didn’t evolve from chimps; we shared an ancestor with them who walked on four legs. Technically, chimps are our genetic cousins).
However about 3 million (30 laks) years ago; bipedalism (walking on two legs) happened. There have been various theories proposed for this sudden evolutionary change ranging from divine intervention to better swimming abilities to evade predators. However what I told as a brief narrative seems to be the most probable ; as there was evidence for a geological change from lush forests to savannahs in Africa exactly three million years ago. Coincidence? Highly unlikely.
Many tend to think about evolution as a sudden jump (Many don’t think about evolution at all) and also that Human beings are the highly evolved forms and we aren’t evolving any more. Nonsense. I have read books where people demand evidence like they’ll believe in evolution when a monkey gives birth to a human baby. Nonsense again!
Evolution happens step by step over many generations and it is utterly important for us to understand it because it has great ‘applicational’ values in our present as well (More on that in another post). Besides that it is exceedingly slow. In our story; Mr.X since had the genetic gift to stand on two legs would have raised more kids who had the same genetic gift than other organisms who would have succumbed to hyenas as they wouldn’t have been able to stand on two legs and hence spot predators.
Eventually the genetic gift wouldn’t be enough as well. The predators would also get a gift (Not from anyone. It would arise spontaneously. That’s called genetic variation). Let’s say out of 10 predators, one might have developed a gift to stalk a prey and ambush it or run faster. Hence creatures like our Mr.X have to adapt too. It is called as the ‘evolutionary arms race’ where various species adapt (run) continuously to stay (survive and reproduce) in the same spot. If they stop, they will die and go extinct.
Hence as time progresses, just standing on two legs wouldn’t have been enough for our ancestors. They had to walk and run on two legs to constantly keep an eye on their predators over the grass. Just remember this is just one pressure factor on our evolution. The other factors were to raise kids, hunt for food, attract many mates and many more. I had just stuck onto bipedalism in this post.
When you think about such simple activities that shaped our ancestors 3 million years ago to the formation of modern humans some 35000 years ago; you tend to appreciate life. Such things make me work on the small things in life which would become a bigger one in the future. Learning about our own species’ history is important atleast in this aspect.
If you have any questions regarding human evolution, please ask me or post as a comment here. You could check out more about human evolution ‘here‘. More posts to come.