“Humans have been studying insects for 200 years and we have understood their evolutionary groups,” says Tihelka. Except for fleas. “People said they were around beetles, or flies, or some kind of fly that adapted to blood nutrition. But they eluded our understanding. “
Tihelka says that’s because fleas are weird. “They have no wings and their anatomy is adapted to [make them] specialized parasites of birds and mammals. It’s hard to find similarities with other groups of insects. “
Tihelka and his colleagues were determined to solve the puzzle. They examined information from around 1,400 flea genes and their possible relatives. They discovered that a family of seven rare species of scorpion flies, called Nannochoristidae, turned out to be the fleas’ closest living relatives. Tihelka calls them the “sisters of all fleas”.
Nannochoristidae are found in New Zealand, southeastern Australia, Tasmania, and Chile. However, their origins go back to the Permian Period. 290 to 165 million years ago, the members of Nannochoristidae may have changed. They evolved from insects that fed on nectar to insects that fed on blood. These ancient flea relatives, some of which were about three-quarters of an inch long (huge for fleas), may even have fed on the blood of dinosaurs.
The reclassification of the tree of life often happens as scientists acquire knowledge. Tihelka says it happens to insects too. Scientists once thought termites were their own group of insects. Then they discovered that they were indeed “a group of cockroaches with a social lifestyle,” says Tihelka. His research on fleas suggests that they should be classified as scorpion flies.
Tihelka and his research group plan to continue studying fleas and scorpion flies to see if they can find further links between the two. After that, he says, insects will keep him busy for a long time.
“Insects are present in all ecosystems and make up two thirds of all animals described,” he emphasizes.
In addition, there are 400 million years worth of extinct insects in the fossil record. Some people refer to the age of the dinosaurs or the age of the birds. “But we [knew all along] It was the age of the insects, ”says Tihelka.
Nevertheless, this age is threatened. Some scientists fear an “insect apocalypse” or the elimination of insects. Many species of insects around the world are declining.
“The only time there was a collapse was on the border between the Permian and Triassic,” says Tihelka 250 million years ago. Ninety percent of all species became extinct. “That was so close when we could wipe out all the insects. But otherwise they were successful. “
Only time will tell if this success will last.
