How cockroaches took over the world

It is believed that the small creature originated from Europe. In fact, it arrived from South Asia just over 2,000 years ago, genetic analysis reveals. The insect spread very quickly because of its “association” with humans. Or more precisely, with human habitats, whether it is a house and its food scraps or a ship departing for a distant destination.

This last aspect does not need to be noted by heredity. Since its first scientific description Platella germanica In 1776 by the Swedish biologist Carl Linnaeus, they were observed to highly value the company of humans, much to their dismay.

The team of researchers in question, led by evolutionary biologist Qian Tang from Harvard University, analyzed the genomes of 281 of these “German cockroaches” collected in 17 countries, including Australia, Ethiopia and the United States. Comparisons between these genomes made it possible to establish that its closest cousin is the European Platila AsahinaiWhich can still be found in South Asia.

The separation between the two branches dates back 2,100 years. Later, about 1,200 years ago, a sub-branch migrated west, to the Middle East. And other cousins B. Asahinai They had migrated east 390 years ago. It turns out that these are moments in history Corresponds to major travel times Military and commercial: those of the Islamic New World 1,200 years ago, and those associated with the expansion of European colonialism in Asia 3 centuries ago.It thus suggests how the cockroach traveled.

the study It was published on May 20 in the American Journal Proceedings of the National Academy of Sciences. It is an adaptable and opportunistic species“The perfect combination of ingredients for the success of a species on a planet shaped by humans,” sums up ecologist Franz Issel, of the University of Vienna.