A week ago, I watched a documentary that explains how marine animals related to land mammals and even to humans. It is very shocking to know that we all come from the ocean. Even today, we live on land, we still cannot survive without water, probably that is one of another proof that we used to live in water. My favorite part in the video is that it shows a predator, crocodile-like fish with a flatten head crawled to the shore. I am very interested to know how this fish evolve to mammals step by step, but the video described this part very briefly.
I also learnt that the size of our brain is the biggest among all the land mammal, which makes us so intelligent and so special. Surprisingly majority of our genes are the same with many other animals, we grow a larger brain through gene mutation. I did some research on human evolution, the first rapid increase in brain size is from 800,000-200,000 years ago. Human brain size evolved during a time of dramatic climate change. Larger, more complex brains enabled early humans of this time period to interact with each other and with their surrounding s in new and different ways. The environment became more unpredictable, bigger brains helped our ancestors survive.
Honestly, I am more interested in why human got the chance to evolve, why not all the apes evolved to human. I think at the same time, we should not ignore the external factors that affect humans behaviors that differ from apes, like inventing farming, herding animals, the use of fire, learn to use simple tools, learn to walk upright and walk with two legs. We invent new techniques and learn from some of our old techniques. I think human is the most successful product of gene mutation.