Humans and chimpanzees share 99.4% of their DNA

SFollowing a recent study carried out in early 2023 in the United States, more advanced analyzes of animal genomes show that humans and chimpanzees share 99.4% of their functional DNA in common.

This emerges from the results of a group of American researchers from Cornell University, who conducted extensive research and analysis over many years.

The study goes even further and reveals disturbing similarities, such as some genes specializing in processing olfactory information that are practically identical in both species.

“The sequences of these special genes are so close that we thought there was no interest for this research”, underlines Andrew Clark, professor of molecular biology at Cornell University, to whom we owe the direction of this research.

This new study clearly confirms existing data showing that the two species, humans and monkeys, share more than 98% of all genetic information on their chromosomes.

The main point of this new study is about what scientists call “useful” information, that is, “effectively contained in genes and used to encode and develop and direct the program for the production of proteins made by cells. Organism.

An important point that sheds new light on our origins and our relationships with other animals. Even better, the chimpanzee suddenly became a close relative of the hominids, calling into question all existing taxonomies.

Furthermore, these results prompted an American researcher to propose a new classification “Homo” (humans and chimpanzees) including the group of hominids including other great apes (orangutans, gorillas and gibbons).

This means that scientists are serious and the paradigm shift is well established. This allows medicine to advance in more ways than one, as these new data “help us understand the function of certain genes, especially those responsible for higher cognitive functions such as emotion or language. They may also accelerate the course of certain serious diseases. Despite genetic similarity, when faced with diseases such as Alzheimer’s disease, AIDS or malaria “Monkeys and humans do not function in the same way,” the researchers note.

It is in this sense that a team at Cornell University began this genome comparison project by deciphering the nucleic acid sequence of 18 million simian DNA sequences.

It builds on earlier work by Celera Genomics, formerly led by biologist Craig Venter. “We have discovered hundreds of small differences between the two genomes that certainly explain the divergent evolution of the two species”, confirms Andrew Clarke.

Cornell researchers go a step further and dig into the tiniest details to back up their analysis. In this sense, they highlighted a specific protein in the inner ear (alpha tectorin), the deficiency of which leads to congenital hearing loss in humans.

According to American experts, “this mutation may also cause language comprehension disorders. In chimpanzees, the genes encoding this protein are very different from those in humans. These variations may explain the limited ability of chimpanzees to understand language.

Pending more in-depth analyses, in a few weeks, all the genome sequences of the two primates should be available online on servers at the National Human Genome Research Institute (NHGRI) in Bethesda, Maryland. .

Abdelhaq Najib, writer-journalist