Scientists say that convergent evolution is much more common than previously thought. The evolutionary tree, or phylogenetic tree, is a branch diagram that shows the evolutionary relationship between various biological species according to their similarities and differences in characteristics. Historically, they were compiled based on their physical characteristics, that is, based on the similarities and differences in the anatomical structures of various species.
However, advances in genetic technology now enable biologists to use genetic data to decipher evolutionary relationships. According to a new study, scientists have found that molecular data are leading to very different results, sometimes overturning centuries of scientific work on classifying species according to physical characteristics.
A new study led by scientists at the Milner Center for evolution at Bath University shows that it is misleading to determine the evolutionary tree of organisms by comparing anatomy rather than gene sequences. This study, published in the journal communication biology on may31,2022, shows that we often need to overturn the academic work of classifying organisms according to their appearance for centuries.
Since Darwin and his contemporaries in the 19th century, biologists have been trying to reconstruct the "family tree" of animals by carefully examining their anatomical and structural (morphological) differences. However, with the development of rapid gene sequencing technology, biologists are now able to use genetic (molecular) data to help very quickly and cheaply piece together the evolutionary relationships of species, often proving that the organisms we once thought were closely related actually belong to completely different branches of the tree.
For the first time, scientists at Bath University compared the morphological evolutionary tree with the molecular data based evolutionary tree, and mapped them according to their geographical location. They found that animals grouped by molecular tree lived closer geographically than animals grouped by morphological tree.
Matthew wills, Professor of evolutionary paleontology at the Milner Center for evolution at the University of bath, said. "Facts have proved that many of our evolutionary trees are wrong." For more than a hundred years, we have been classifying organisms according to their appearance and anatomical structure, but molecular data often tell us a quite different story. Our research has proved statistically that if you build an evolutionary tree based on the molecular data of animals, it is often more consistent with their geographical distribution. Where things live their biogeography is an important source of evolutionary evidence familiar to Darwin and his contemporaries. For example, elephant shrews, aardvarks, elephants, golden moles, and swimming manatees all come from the same large branch of mammalian evolution -- although they look completely different from each other (and live in very different ways). The molecular tree classifies them into a group called afritheria. The so-called reason is that they all come from the African continent, so this group matches with biogeography. "
The molecular phylogenetic tree shows that elephant shrews are more closely related to elephants than shrews
The study found that convergent evolution - when a feature evolves separately in two genetically unrelated biological populations - is much more common than biologists previously thought.
Professor Wells said. "We have many famous examples of convergent evolution, such as the evolution of flight in birds, bats and insects, or the evolution of complex eyes in squid and humans. But now through molecular data, we can see that convergent evolution has been taking place all the time - things we think are closely related are often far away from the tree of life. People who live on imitators usually have no relationship with the celebrities they imitate, a family Individuals in don't always look alike -- nor do evolutionary trees. This proves that evolution is just constantly re inventing species. Every time we encounter problems in different branches of the evolutionary tree, we will have similar solutions. This means that convergent evolution has been fooling us -- even the smartest evolutionary biologists and anatomists -- for more than 100 years! "
Dr. Jack o'easton, the researcher and the first author of the paper, said. "The idea that biogeography can reflect the history of evolution is a big part of the reason that prompted Darwin to develop his theory of evolution through natural selection, so before that, it was not really directly considered as testing the accuracy of the evolutionary tree in this way, which is quite surprising. The most exciting thing is that we found that the molecular tree is more suitable not only in groups like Africa, but also in birds, reptiles, insects and There are also strong statistical evidences in the whole life tree of plants. It forms such a broad pattern that it is more likely to be a general test of different evolutionary trees, but it also shows how common convergent evolution is when it misleads us. "