By Jonny Lupsha, Current Events Writer
Billions of cicadas are popping up in the eastern United States. For the first time in 17 years, a brood of the flying insects will sing, mate, and die in a four- to six-week mass breeding event. Insects flew 400 million years ago.
Periodic cicadas occur only in the eastern and central United States for a set number of years per mating cycle. and photo by RobDun / Shutterstock
If you literally haven’t heard it, the 17 year cycle of cicada mating has returned. In the eastern United States, billions of flying insects are throwing a party that begins with men singing a mating song to women. Once the females answer the call, they select a tree to house their eggs for the next 17 years and insert them.
Four to six weeks later, the adults will die. Unfortunately, this will clean up the Americans on the east coast, move on and drive over billions of cicada corpses.
This noisy affair will conquer Americans from northeast Texas to Cape Cod. It may be a nuisance, but it is thanks to many paleontological wonders. In his Major Transitions in Evolution video series, Dr. Anthony Martin, Professor of Practice in Emory University’s Department of Environmental Studies, explains why insects are so populous. It began 400 million years ago in the Devonian period.
A pest of insects
“Flight was a major evolutionary innovation in insects, and flying insects in particular have changed terrestrial ecosystems in really significant ways,” said Dr. Martin. “Recent DNA analysis shows that insects’ closest living relatives are this group of crustaceans known as remipedes. This means that insects are actually more closely related to crustaceans than they are to myriapods such as millipedes and millipedes. “
According to Dr. Martin, insects must have evolved from six-legged terrestrial arthropods. Their evolutionary success is based on a number of factors. First, insects have very high reproduction rates. With the right types and conditions, this can literally result in multiple generations per year. Second, insects have an incredible number of offspring. In combination with the high reproduction rates, the insects are guaranteed great genetic variability.
“As a result, insects in their population respond very quickly to any type of selection pressure,” said Dr. Martin. “Just ask scientists at chemical companies that make pesticides. They often change their formulas because the pesticide-resistant insects adapt so quickly. “
He said this was an example of what he would call “unnatural selection”. In attempting to control pest populations, humans have inadvertently chosen better adapted insects that will then reproduce larger numbers of pesticide-resistant offspring. This is analogous to a public concern about the medical industry – that is, when people fight disease, only the weaker diseases die, leading to the spread of “super diseases”.
At the same time, the insects’ early ability to fly gave them an advantage over many other creatures on earth.
“Knowing how fantastic predators modern dragonflies are today, Meganeura and those other giant carbon-age dragonflies must have been the scariest things in the air, which gives even small vertebrates a good reason to be afraid of attack from above,” said Dr. Said Martin. “Even if you consider that flying vertebrates have not yet evolved, once these insects have evolved, they ruled the sky.”
Edited by Angela Shoemaker, The Great Courses Daily
