It was insects that first learned to fly, and it happened around 400 million years ago, according to new research.

An international team of about 100 scientists published the first exhaustive family tree for insects in order to better understand the relationships between insect species and how they evolved. The insect “tree of life” helps researchers answer old questions about insects’ origins and evolution — and on thing it has revealed is when insects first developed wings, according to Entomology Today.

Insects first started appearing on earth 500 million years ago, and it took about 100 million years for the first flying insects to appear.

Up until now, scientists did not have a comprehensive picture of how insects evolved at their disposal. Insects are especially important because, in terms of species, insects are the largest part of the evolutionary picture. Sequencing technology has allowed scientists to compare large amounts of data and come up with an insect family tree to fill knowledge gaps.

Scientists used a data set of only 144 carefully chosen species to create reliable estimates on when insect species originated and how the relationships of each insect group intersect.

Insects came along about the same time as plants 480 million years ago, and that both shaped the ecosystem as they evolved. Insects evolved the ability to fly long before animals, and it happened at about the same time that plants began to grow tall.

Experts in the fields of biology, morphology, paleontology, embryology, taxonomy, and computing participated in the research.