Why are cockroaches so common? We are the reason!

Cockroaches, which are very common pests around the world, are not found in nature, although they cause a lot of trouble to people. Scientists have revealed how cockroaches evolved and how they became so widespread.

The reason cockroaches are so common is us humans.

By sequencing the DNA of the German cockroach (Blattella germanica), scientists have traced its origins to eastern India and Bangladesh, revealing an intriguing story about how it contributed to the evolution and spread of one of humans’ most hated pests.

Cockroaches came to people’s attention when they were spotted in an army food depot in Eastern Europe during the Seven Years’ War, which took place between 1756 and 1763. Opposing forces gave this insect different names. The Russians called it the “Prussian cockroach,” while the British and Prussian soldiers called it the “Russian cockroach.”

In 1767, Swedish biologist Carl Linnaeus classified and named this species (Blatta germanica). Blatta means “light-loving” in Latin, and germanica comes from the fact that the samples were collected in Germany. Later this species was renamed Blattella to group small cockroaches.

As scientists discovered related species with similar anatomy in Africa and Asia, they suggested that cockroaches may have first evolved in Africa or Asia, but they were unable to test these theories. This is where gene sequencing came into play.

Scientists took DNA from 281 cockroach samples from 17 countries. When they compared the DNA sequence of the German cockroach to similar species from Asia, they found it was nearly identical to Blattella asahinai from the Bay of Bengal.

More than 80 percent of the German cockroach samples were a perfect match. The remaining 20 percent showed little difference. This suggests that the two species diverged only 2,100 years ago, a very short period of time in evolutionary terms.

Scientists think Blattella asahinai adapted to living alongside humans after their natural habitat was cleared by farmers. The ancestors of this species moved from Indian fields to buildings and became dependent on humans. So how did they spread around the world?

The researchers analyzed another gene sequence (SNPs) in the DNA of the German cockroach. With this analysis, they revealed how the German cockroach spread from its native land to the world. The first wave of migration occurred westward from the Bay of Bengal about 1,200 years ago, probably carrying with them the trade and armies of the Islamic Umayyad and Abbasid Caliphates.

The second wave moved towards Indonesia with European trading companies about 390 years ago. The German cockroach arrived in Europe about 270 years ago, matching historical records from the Seven Years’ War.

Because humans naturally disliked cockroaches, the survival of these invaders depended on their ability to remain stealthy. The German cockroach has become nocturnal and avoids open areas. He stopped flying, but kept his wings.

Therefore, we are responsible for the spread of these cockroaches, which we often see in our homes, around the world. What are you thinking? Please don’t forget to share your thoughts with us in the comments section below.