In his fundamental work “the Origin of species by means of natural selection”, which was published in 1859, Charles Darwin put forward a number of bold at that time ideas about the nature of evolution.
In particular, he suggested that “species of the larger genera in each country vary more frequently than the species of the smaller genera” (in other words, the more types consists of a family, the more subspecies within those species).
Now, nearly 140 years after the death of a naturalist, that his idea was confirmed by the researchers from the University of Cambridge.
Recall that the term “species” in biology refers to the group of animals that share physiological, behavioral and other characteristics, can freely interbreed with each other, naturally distributed within a specific range and similarly change under the influence of external factors.
Subspecies (Darwin called them “varieties”) is a population that differ from each other by certain traits and/or habitats, but not strong enough to consider them different species.
At the Northern giraffes, for example, there are several subspecies, and the red foxes their 45. Meanwhile our species, Homo sapiens, according to most experts, the subspecies has not.
to test the hypothesis of Darwin, the researchers analyzed a huge database on the classification of mammals — evidence gathered over hundreds of years from all over the world.
the Authors have calculated the number of species in the genus and the number of subspecies to species for various animal groups defined the “age” of various types and subspecies, and assessed how closely they are linked.
as a result, scientists have confirmed Darwin’s idea that diversification (increase diversity), between species and between subspecies are related: the more one or the other genus contains the species, the more subspecies account for the latter.
moreover, it was found that the subspecies are formed, diversifitsiruetsya and increase the number of different ways depending on environmentss habitat. And these trends in turn affect the likelihood that the subspecies will eventually become a separate species.
the results show that the correlation between species and subspecies diversity is most noticeable in nashotah mammals — those that live in the ocean or spend a lot of time in the air. This animals natural barriers (mountains, for example) not bothering to learn new areas.
a Logical question that the scientists asked was, is it possible to consider the subspecies as the “embryo” of a new kind.
“the Response has been positive, says lead author Laura van Holstein (Laura van Holstein). — But evolution is not determined by the same factors in all groups, and the first time we found out why, because it considered the relationship between species diversity and the diversity of subspecies”.
According to experts, the new data are important for the conservation of biodiversity on the planet, because today many animals is threatened by extinction because of environmental changes. In other words, our actions have an impact on the future evolutionary dynamics.
“With the development of models we can use our results to predict how human activity will affect future evolution, changing environment [of certain] species — says van Holstein. — The impact on animals will vary depending on how it affects their ability to travel long distances”.
Article on the outcome of this work is published in the journal Proceedings of the Royal Society B.
earlier, “Conduct.Science” (nauka.vesti.ru) described how the watchers checked another curious hypothesis of Charles Darwin. We wrote about the work, which partly confirms the teachings of the naturalist, and partly contradicts it.