Even though Charles Darvin titled his famous book ‘The Origin of Species’, he considered the mechanism of new species’ origin a great mystery. Even now, one of the greatest mysteries of biology is how two groups of animals become genetically incompatible. It is possible to imagine that two groups of animals become separated in space and lose the ability to breed with each other for a long time, gradually adapt to different environmental factors until they lose physical ability to mate even living at the same territory. Development of new species without physical isolation is much more difficult to explain because of free exchange of genetic information between individuals. Even more difficult to comprehend is the fact that changing only one gene may be sufficient to create new biological species.

A gene called Prdm6 was found long time ago as a gene involved in recombination, the process of crossing chromosomes and exchanging DNA regions between paternal and maternal chromosomes in the gonads. The process takes place only during maturation of reproductive cells – spermatozoids and oocytes. The DNA shuffling is the reason why each organism is unique. So far, DNA recombination was not associated with the creation of new species. Scientists found that the protein Prdm6 has several so-called Zn-fingers that are encoded by short DNA repeats called satellite DNA. As satellite DNA is located in hot-spots of DNA recombination, it is frequently mutated and repaired. As the result, Prdm6 protein gets more or less repeats of its Zn-fingers. It appears that the chromosomes that have different variants of the gene cannot properly pair and exchange genetic information during gametogenesis. All animal species have homologous Prdm6 genes. Certain lines of laboratory mice that express different variants of Prdm6 protein cannot produce fertile offspring. Scientists found that different populations of humans also produce Prdm6 proteins with different number of Zn-fingers. It is conceivable that people with certain variants of Prdm6 proteins may not produce fertile children and may develop into a new human species. This process will require selective pressure, either natural or artificial, and many years to develop true new Homo species.

All living species on Earth, even microscopic viruses compete with each other for space and resources in order to survive and reproduce. Some viruses are exceptionally aggressive in expanding and using resources so that they cease to exist because they consume all resources. The “virus” Homo sapience is not an exception. It leaves fewer and fewer places on the planet for wild flora and fauna. Larger organisms are especially vulnerable to the ferocious “virus” Homo sapience. Smaller organisms are more lucky and have more chances to avoid the lethal weapons of cunning biped predators. Life on the planet becomes smaller in size…

About 25,000 years ago, Homo sapience began to actively explore and occupy the planet and use its resources. Humans destroyed about half of all terrestrial species of mammals weighting over 45 pounds. Mammoths, mastodons, saber-toothed tigers, giant sloths, beavers, as well as many other representatives of mega fauna became extinct as the result of direct and indirect actions of humans.

Anthony Barnosky, an ecologist at the University of California at Berkeley, says that most species of large mammals disappeared during the time interval of 4000 years, which ended about 11,000 years ago. During that period, Australia has lost 88% of the species diversity of large mammals, South America – 83%, North America – 72%. Africa and Eurasia lost only one in five and a one in three species of large mammals respectively.

P.S. Jared Diamond in his book target=”_blank”"Guns, Germs and Steel. The fate of human societies” explained this latest animal extinction by the fact that people inhabited Australia and the Americas relatively recently and already possessed developed weapons and hunting techniques. Animals simply were not ready for the sudden appearance of a new predator. As opposed to Australia and Americas, humans were present in Africa and Eurasia for a very long time and had much more time to gradually adopt the modernization of weapons of Homo sapience.

The world, as we know it, will change. This is inevitable. There are only two simple choices that are available to all biological species at harder times: either change or die. Humans as a biological species face the very same choice. The change is going to be either biological or technological. It is possible to slow harsh natural selection, as we just did through science and technology, but genetic changes are accumulating in the population in the background and one day will reveal themselves in an ugly way. As we are canceling natural selection, human population becomes more and more diverse, meaning sick and weak. Natural selection has to be replaced with artificial selection and use of intelligent approaches to improve the genetics of Homo sapience. We will also learn to use different sources of energy and use different habitats to live. All these changes are noticeable even today.