MSU researcher Elena Temereva specialist, invertebrate zoology, in the course of his new work described the appearance of distant human ancestors. Her research has focused around the concept of bilateral or bilateral symmetry, which have many modern animals, including man.
All bilaterally symmetrical animals, biologists believed, had a common ancestor. Rather, he appeared on Earth at the end of Venda – the last geological period of the Neoproterozoic – 635-541 million years ago.
Unlike bilaterally symmetrical animals (Bilateria), organisms that time were the so-called radial symmetry. That is, they have the shape of the body, which coincides with itself when rotated about the central axis of the body.
In order to understand what kind of contribution to science work Temereva worth digress. Western scholars generally believe that the ancestor of bilaterally symmetrical animals was called netselomichesky worm – an animal with a primitive nervous system and the absence of a special body cavity, called tselómom. Russian scientists have a different point of view and believe that the common ancestor of bilaterally symmetric animals as time had a whole and had a rather intricate physiology.
“The hypothesis of the origin of bilaterally symmetric animals from the general ancestor of cnidarians, which had a multi-beam symmetry and multiple camera gastric cavity, gave rise tselómu, was first proposed by the British zoologist Adam Sedgwick. This idea was developed in the works Head of the Department of Invertebrate Zoology, Faculty of Biology, Professor, Corresponding Member of the Russian Academy of Sciences Vladimir Malakhov, “- says a press release from the Moscow State University .
It is this point of view studied in his new study, Dr. Temereva described their findings in an article published in the scientific journal PLOS ONE.
Dr Temereva studied representatives of biological type inarticulate brachiopods, or brachiopods. Researcher interested in a particular type of these marine organisms – Lingula anatina. According to biologists, Lingula is one of the oldest members of their type, which appeared about 500 million years ago and survived to the present day.
“Our research shows that one of the trunks of bilaterally symmetrical animals – subtypes Lophotrochozoa, which includes the largest variety of types of living organisms – there is a group lofofornyh animals -rasskazyvaet Elena Temereva. – peyote – a special part of the body that carries tentacles. Lophophora have representatives of the three types of the animal kingdom: phoronid, brachiopods and bryozoans. This special structure allows researchers peyote combine these three types into a single group – Lophophorata. However, numerous data Molecular Phylogenetics indicate that a single group lofofornyh animal does not exist “.
Scientists have used a variety of sophisticated research techniques, including various types of microscopy and three-dimensional reconstruction, and proved that lofofornyh animals can really be a separate group. All of them had a single common ancestor that had tentacles.
The main evidence in favor of this hypothesis can be considered the fact that all organisms lofofornyh has a similar structure of the nervous system that can not be the result of convergent evolution (when the same symptoms appear in different animal species, regardless).
“In view of the fact that there are tentacles in two main trunks of bilaterally symmetrical animals, it is logical to assume that they were from a common ancestor. There were tentacles the common ancestor of chordates, which include, including man, “- says Dr. Temereva.
Temereva Elena and her colleagues hope that through their study, the researchers will be able to clarify the evolutionary picture of the ancestors of humans and other bilaterally symmetrical animals. Also, Russian biologists believe that the results of this work will help in building a natural system of the animal kingdom, through which the classification of species will become more specific.
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