AI used to test evolution’s oldest mathematical model


16-08-2019
  Butterfly co-mimic pairs from the species Heliconius erato (odd columns) and Heliconius melpomene (even columns). Illustrated butterflies are sorted by greatest similarity (along rows, top left to bottom right)  Credit: J Hoyal Cuthill, photo credits S Ledger and R Crowther

Researchers have used artificial intelligence to make new discoveries, and confirm old ones, about one of nature’s best-known mimics, opening up whole new directions of research in evolutionary biology.

The researchers, from the University of Cambridge, the University of Essex, the Tokyo Institute of Technology and the Natural History Museum London used their machine learning algorithm to test whether butterfly species can co-evolve similar wing patterns for mutual benefit. This phenomenon, known as Müllerian mimicry, is considered evolutionary biology’s oldest mathematical model and was put forward less than two decades after Darwin’s theory of evolution by natural selection.

The algorithm was trained to quantify variation between different subspecies of Heliconius butterflies, from subtle differences in the size, shape, number, position and colour of wing pattern features, to broad differences in major pattern groups.

This is the first fully automated, objective method to successfully measure overall visual similarity, which by extension can be used to test how species use wing pattern evolution as a means of protection. The results are reported in the journal Science Advances.

The researchers found that different butterfly species act both as model and as mimic, ‘borrowing’ features from each other and even generating new patterns.

“We can now apply AI in new fields to make discoveries which simply weren’t possible before,” said lead author Dr Jennifer Hoyal Cuthill from Cambridge’s Department of Earth Sciences. “We wanted to test Müller’s theory in the real world: did these species converge on each other’s wing patterns and if so how much? We haven’t been able to test mimicry across this evolutionary system before because of the difficulty in quantifying how similar two butterflies are.

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Image:  Butterfly co-mimic pairs from the species Heliconius erato (odd columns) and Heliconius melpomene (even columns). Illustrated butterflies are sorted by greatest similarity (along rows, top left to bottom right)

Credit: J Hoyal Cuthill, photo credits S Ledger and R Crowther

Reproduced courtesy of the University of Cambridge

 

The University of Cambridge is acknowledged as one of the world's leading higher education and research institutions. The University was instrumental in the formation of the Cambridge Network and its Vice- Chancellor, Professor Stephen Toope, is also the President of the Cambridge Network.

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