Insects are everywhere and, as far as we humans are concerned, they always have been and always will be.
We, as a species, have been around for about 200,000 years. The first members of the primates – the taxonomic order we belong to – emerged around 80 million years ago. And the first vertebrates to leave the sea and live on land did so about 360 million years ago. By that time, the insects had been around for some 120 million years already and had had time to evolve wings and conquer the air, some 180 million years before the next type of animal – the pterosaurs – would learn to fly.
Until recently, the timeline of insect evolution was mostly based on fossil evidence, and the oldest known insect fossil is ‘only’ 410 million years old. But last week, the first results of a research study that looked at the insect family tree by comparing the DNA sequences of 144 different species were published in the journal Science.
The more than 100 researchers from 16 countries that collaborated on this project first sequenced all the genes of these different insects and then looked for genes that were common to all species. They then used some serious computing power and clever algorithmic tricks to analyse how these genes compared and to integrate the findings with evolutionary models and fossil evidence. The result is a much more accurate timeline than we had from previous research, placing the origin of insects around 479 million years ago and that of insect flight around 406 million years ago.
Today, the insects are the most species-rich, most numerous, and arguably the most important group of animals, and now we know why; they had a very long time to evolve all that diversity!