Study by scientists at U.K.-based University of Bath suggests evolutionary trees trusted for 'over a hundred years' could be wrong

An evolutionary tree can be a tangled web, and a team of British scientists at the Milner Centre for Evolution at the University of Bath say that using anatomical comparisons to unravel those trees for organisms could prove to be misleading.

According to a University of Bath news release, a team of scientists from the university released a study that was published in Communications Biology, saying that hundreds of years of scholarly efforts that identified living things based on physical attributes may prove to be an exercise in futility. According to the release from the U.K.-based university, rapid genetic sequencing has advanced to the point where biologists can use it as a tool to build the evolutionary relationships of living things like a sort of Darwinian jigsaw puzzle that finds things once believed to be closely related may belong in completely different branches of the evolutionary tree.

“For over a hundred years, we’ve been classifying organisms according to how they look and are put together anatomically, but molecular data often tells us a rather different story,” Matthew Wills, a professor of evolutionary paleobiology at Milner Centre for Evolution at the University of Bath, said in a podcast. “Our study proves statistically that if you build an evolutionary tree of animals based on their molecular data, it often fits much better with their geographical distribution.”

Moreover, the team at Bath used morphology and molecular data to compare evolutionary trees, according to the university’s news release, and mapped them by geographical locations. This led them to conclude that many animals grouped by molecular trees lived in closer proximity geographically than animals grouped by morphological trees, according to the release.

“Where things live – their biogeography – is an important source of evolutionary evidence that was familiar to Darwin and his contemporaries,” Wills said in the podcast. “For example, tiny elephant shrews, aardvarks, elephants, golden moles and swimming manatees have all come from the same big branch of mammal evolution – despite the fact that they look completely different from one another (and live in very different ways).”

According to the news release, the scientists also found that convergent evolution, in which a key characteristic develops separately in two distinctly different unrelated groups of animals, happens more frequently than scientists once believed. The team, according to the university, pointed out that molecular data can serve as a roadmap that is varied from the map created based upon appearance and anatomical features.

“Molecular trees have put them all together in a group called Afrotheria, so-called because they all come from the African continent, so the group matches the biogeography,” Wills said in the podcast.

Dr. Jack Oyston, who is the first author of the study, explained the belief that biogeography’s reflection of evolutionary history was a driving force for Darwin to develop his theory of evolution through natural selection.

“So it's pretty surprising that it hadn't really been considered directly as a way of testing the accuracy of evolutionary trees in this way before now,” he said in the university’s news release.

The study, according to the news release, is an indication that evolution continues to reinvent things and a similar solution is typically found each time a similar issue is encountered along a different branch of an evolutionary tree, something that misled even the best anatomists and evolutionary biologists for more than a century. The study, according to the release, casts a spotlight on the importance of molecular data in putting together the puzzle of the evolutionary history of organisms.

“Our study proves statistically that if you build an evolutionary tree of animals based on their molecular data, it often fits much better with their geographical distribution,” Wills said. “Where things live – their biogeography– is an important source of evolutionary evidence that was familiar to Darwin and his contemporaries."