From ape humans to primitive humans, to intelligent humans, and then to modern humans, we have experienced a long evolution to become what we are now. Evolution sounds like an ancient phenomenon, as if it only happened to human ancestors millions of years ago. However, evolutionary geneticists have found that human beings are still undergoing simple evolution due to gene mutation. Simple evolution is the mutation of gene, that is, the accidental change of gene in the process of DNA replication.
Parents will pass on genes carrying certain traits to their offspring. These gene transmission may occur through natural selection. Carriers of dominant genes can survive, adapt to the environment and reproduce better. From humans walking upright on two feet to eagles flying with open wings, the adaptability of every species can be traced back to the inheritance of dominant genes for generations.
Neanderthals lived about 2.6 million to 11700 years ago. In the long history of evolution, many close human relatives, including Neanderthals, have been extinct, leaving us only to live and reproduce in this world. This makes people think, is it because we are lucky or we are different from our close relatives that nature chooses us?
To do this, the scientists analyzed the metabonomics of humans, chimpanzees and macaques in muscles, kidneys and three different brain regions. The results showed that the reason for the survival of modern human is the mutation of the genome and the decrease of the stability of adenylate lyase, which leads to the decrease of purine synthesis. But the mutation did not occur in Neanderthals, so scientists believe that the mutation affected the metabolism of brain tissue, thus promoting the evolution of modern humans into an independent species.
Adenylate lyase is an enzyme involved in purine synthesis in DNA. This mutation will lead to the substitution of amino acids in adenylate lyase, which greatly reduces the activity and stability of adenylate lyase, and leads to the decrease of purine concentration in human brain.
More importantly, this mutation only occurs in humans, not in other primates or Neanderthals. By introducing the mutation into the mouse genome, the mutated mice produced less purine, and the introduction of an ancestor gene into human cells led to obvious metabolic changes, which strongly proved that the mutation is indeed the reason for the particularity of human metabolism.
Although there is no real Neanderthal as the research object, the researchers verified the hypothesis in mice and cell models, and effectively predicted the metabolic characteristics of modern people. At present, this research is published in the Journal of eLife. In the future, we hope this research can bring more interesting findings to human beings.
