A new study analyzing the evolution of insects has discovered some startling new data. It has also confirmed some theories that have been around for a while and is likely to result in a greater understanding of evolution as a while. This study is one of the biggest to ever be undertaken. A team of one hundred scientists from ten different countries examined 144 species of insects, with the aim of creating a “family tree” for insects, which would allow them to create an insect evolution timeline. The journal Science recently published the results of the study.
Michelle Trautwein, Schlinger Chair of Dipterology and assistant curator at the San Francisco-based California Academy of Sciences, explained that the scale of the project was incredible in regards to how many people collaborated as well as the type of scientists working on the study, but also regarding the data that was uncovered.
Bernard Misof led the team of scientists at the University of Bonn. He recruited scientists who had a focus on DNA, others who studied the shapes and bodies of insects, paleontologists with a specialty in insects, and even a team of computational scientists whose job it was to create new algorithms and software programs to analyze the huge quantity of data.
Trautwein explains that Misof achieved the unachievable when one considers the various types of entomologists that he brought on board, each one of them with their own ideas regarding insect evolution in terms of the how and the where. She likened his job to attempting to herd cats, and stated it was an incredible accomplishment.
She went on to explain that scientists had been trying to figure out the tree of life of insects for one hundred years, and while the study didn’t generate shocking new data, it did offer a large, comprehensive quantity of information that provided confirmation for a story that scientists only knew bits and pieces of. The study’s results confirm the long, large and continuing insect evolution story.
Insects showed up on the planet approximately 500 million years ago, being some of the first creatures to appear on land. They began their evolution at about the same time as plants on land, and, together, they helped create the early environments on earth. The oldest lines of insects were quite close to creatures such as silverfish, namely ground-dwelling, flat, wingless insects. Approximately 400 million years ago, some of these insects evolved to grow wings.
Trautwein explains that this immense transition from an evolutionary viewpoint has incredible importance because it completely changed the direction insects were evolving in. At the time, she says, there were no other creatures in the air, meaning that they had all this area to themselves. It gave them the opportunity to spread out and circulate in different ways, and it also allowed them to get away from predators. It significantly changed the evolution game.
The study also found there was a connection between the development of wings in insects and changes to plants. Insects started to grow wings when plants became taller and forests began to grow, so there is clearly a connection between these critical points in the timeline of evolution of life. Trautwein explains that such associations, with different organisms evolving in synthesis, has happened throughout evolution’s history.
Trautwein feels that entomologists are going to find the fact that lice have a shared ancestry with insects with a genetic tendency towards metamorphosis really controversial. Insects that go through total metamorphosis make up a significant percentage of insect diversity. These creatures can start out as one shape, like grubs, maggots or caterpillars, and completely change their bodies, making the adult insect completely different to the adult, which Trautwein states was another critical turning point in the evolution of insects.
In regards to size, the study set a new standard when it comes to examining the genome of insects. Trautwein explains that researchers have studied genes over the past few decades, but they have only analyzed one or two at a time across populations of insects. The project analyzed 1,500 genes, which is a significant portion of all expressed genes belonging to the insect genome.
The volume of data was so huge, Trautwein explained, that when they received it, it was simply too large for analysis as they didn’t have the computer power to handle it. The study still had to run on multiple supercomputers for a number of months even after new algorithms and software programs were developed.
The study also confirmed the hypothesis that insects are part of the crustacean family, in other words beetles and shrimp are related. From the point of view of evolution, Trautwein feels this is highly important.
Trautwein explains that the two lines of creatures are quite similar. Crustaceans, on the one hand, are this immense lineage of segmented animals that dominate the oceans, while insects have evolved from crustaceans but have become dominant of terrestrial environments, showing that both lineages dominate the planet, yet do so in different ways.
However, Trautwein feels that the most important achievement of the study is building of the framework for insect evolution. The immense amount of data will enable scientists to ask a wide range of specific questions in regards to the genetic mechanisms that are behind some of the significant changes that took place in the planet’s life.