Intricacies of insect evolution revealed
7 November 2014
Insects evolved at the same time as the earliest land plants around 480 million years ago, an international study has revealed.
The earliest fossil evidence for insects is dated at around 400 million years old, but the new study uses genetic techniques to corroborate estimates that they evolved much earlier.
Insects are the largest and most diverse group of animals on the planet, and played a key role in shaping Earth’s early ecosystems.
Learn to fly
Insects were the first creatures to evolve flight, developing wings around 400 million years ago – 175 million years before the pterosaurs, the next animals to take to the skies.
The evolution of flying insects coincided with land plants growing taller to form large forests, according to the first results of the 1KITE project.
More than 100 researchers from 10 countries are collaborating on the 1KITE project (1,000 Insect Transcriptome Evolution). The project aims to study all of the expressed genes in more than 1,000 insect species, encompassing all recognised insect orders.
The consortium is led by Dr Karl Kjer (Rutgers - State University of New Jersey, USA), Dr Xin Zhou (Deputy Director of the China National GeneBank, BGI-Shenzhen), and Dr Bernhard Misof (Zoological Research Museum Alexander Koenig, Bonn, Germany).
The study revealed the origins and relationships of all the major insect groups by analysing the data from 144 select species, as reported today in the journal Science.
The wealth of data collected for the project corroborated earlier evidence that insects likely evolved from a little-known group of venomous crustaceans called remipedes.
Museum researcher and 1KITE collaborator Bjoern von Reumont has worked for nearly ten years on this crustacean group, and collected the remipedes used for the project from underwater cave systems in Mexico.
'This is the first large-scale study including all insect lineages,' said von Reumont. ‘It answers many long-held questions about the evolution of the world’s largest and most diverse group of animals.’
Everyday influence of insects
Knowing the history of insect evolution also helps us understand their impact on our present-day ecosystems and the natural resources that they support and threaten.
'Insects are of immense ecological, economic and medical importance and affect our daily lives, from pollinating our crops to vectoring [transmitting] diseases,' said Dr Misof.
'We can only start to understand the enormous species richness and ecological importance of insects with a reliable reconstruction of how they are related.'
The data generated by the study could also be used to target pest species by studying their metabolic pathways - the sequences of chemical reactions occurring in their cells.
- by Hayley Dunning