DNA analysis traces the history of the first human mosquito bites
Mosquitoes have been biting humans for over a million years and probably much longer.
Analysis of DNA from 38 modern mosquitoes suggests an ancestral mosquito species evolved a preference for feeding on early humans between 2.9 and 1.6 million years ago, the researchers wrote on February 26 in Scientific reports.
The team studied 11 species of mosquitoes from Anopheles leukosphyrus group, chosen because they gave a good overview of the genetics of the entire group. Some species were “anthropophilic” mosquitoes – feeding on humans – notably Anopheles is tough And Anopheles bamaiiiwho both spread malariawhile others fed only on non-human primates (mainly monkeys) or both.
The team used genetic data to reconstruct the evolutionary history of insects based on the mutation rates of their genes. This allowed researchers to estimate when mosquitoes first bit humans and where – a submerged landmass called Sundaland, the remnants of which today are the Malay Peninsula, Borneo, Sumatra and Java. THE leukosphyrus This group was the first to adapt to bite humans, while other types of mosquitoes only acquired this preference in the last 10,000 years.
“We didn’t expect this group to have appeared so long ago,” says evolutionary biologist Catherine Walton of the University of Manchester in England. “The most parsimonious explanation is that it was in response to the arrival of these early hominids.”
Before humans arrived, mosquitoes fed exclusively on the blood of non-human primates living in the rainforest canopy. This was the “ancestral behavior” of insects, and previous studies indicate that non-human primates began biting more than 3.6 million years ago.
Archaeologists still debate when early human ancestors from Africa spread to Asia. But the new mosquito genetics study independently suggests the movement occurred about 1.8 million years ago, and it matches a recent study that date of oldest Homo erectus skulls in China around the same time.
H. erectus must have lived in large numbers in Southeast Asia to aid adaptation to mosquito bites, which appears to have been based on the unique odor of early humans. “We need an abundance of Homo erectus really an evolutionary change is happening,” Walton says.
And even though only about 100 of the 3,600 species of modern mosquitoes have evolved bite humansSince then, insects have been ruining quiet evenings.
