Researchers find out how and where evolution is going
The research we are going to tell you about today was planned by researchers from the Department of Evolutionary Morphology at the Schmalhausen Institute of Zoology long ten years ago. In 2014, when the Ukrainian zoologist and paleontologist Pavel Gol’din left the occupied Crimea and came to Kyiv, the department decided that they would definitely perform this research. They decided to apply for funding, buy modern equipment, engage a multidisciplinary team, and gain important knowledge.
The researchers submitted a good application for the call ‘Support for Research of Leading and Young Scientists’ of the National Research Foundation of Ukraine and were awarded a grant. This year they plan to complete the project ‘Integration of mammalian organism as a proxy of stability at aquatic and aerial life (as illustrated by skeleton traits)’.
What is the essence of the research?
According to Professor Gol’din, the project studies two groups of mammals – bats and cetaceans which are significantly different from all other animals. “For example, we move in two-dimensional space, walk on the ground, our legs are at the bottom and our head is on top,” the researcher explained without a shadow of a smile.
Whales and bats have evolved to swim and fly and now operate in a three-dimensional environment. For these mammals, ‘top’ can become ‘bottom’ in a second, and vice versa. “They live in an environment where there is no support point (and therefore no need to lean on anything). In these conditions mammalian organisms change and, first of all, the skeleton is transformed,” the researcher continued.
In other words, the skeleton, in whole or in part, ceases to perform its supporting function. In whales, it seems to be ‘freed’ from restrictions and acquires other functions. In bats, on the contrary, the skeleton becomes very stable, but the bones in it are thin and light. Bats developed wings, whales developed fins. The mammals themselves acquire completely new forms needed in the new environment.
The goal pursued by the researchers was to figure out how the transformation process takes place, how different parts of the skeleton (or different bones in the skeleton, or different parts of the same bone) are connected to each other. How do these connections increase and decrease? And most importantly, how does this happen in the course of evolution? In what direction does the evolution of these and other structures go?
The working hypothesis of the researchers was that in the initial stages of the evolution the connections within the skeleton break down, and in the following stages they ‘fold’ into something else, into a new combination. Of course, everything turned out to be much more complicated.
In the study, the researchers realized that the evolution of the skeleton could be described with the help of a new language, the language of integrated systems.
“To calculate the joint evolution we took points on the surface of the bones in three-dimensional space, took into account the joint evolution of metric features (those that can be measured with a ruler), evaluated the evolution of anatomical networks – structures in which the skeleton is represented as a network of elements, and each bone or tooth is an element of the network,” continued the professor. “As a result, we found out how the evolution of mammals moves when the environment changes.”
With the grant funding the researchers purchased three 3D scanners – for scanning small, medium, and large objects. With this equipment they are able to scan both the skull of a bat and a whale. They also purchased a PCR machine which makes it possible to measure gene expression in the body.
With the help of 3D scanners the project team created many 3D models of skeletons and individual bones of modern and fossil mammals. In order to create these models, they collected data from Ukrainian and foreign museums.
Pavel Gol’din believes it is a great success that he managed to keep the team together despite the war. Although there were many dangerous moments (both for people and for the digital archive). Some of the project implementers had to leave their homes near Kyiv at the last minute, as these towns and villages were occupied the following day. Another researcher, assistant Pavel Otriazhyi, left Kharkiv and saved the full version of the archive from the shelling.
Just as planned, the team consisted of very professional and motivated researchers. Igor Dzeverin, a well-known researcher and specialist in mammalian morphology and evolution, is responsible for the general theory and the ‘bat block’. Maria Gkhazali analyzes evolutionary trees, calculates evolutionary rates, and works on the project methodology. The anatomist Karina Vishnyakova collects primary field data for morphological and genetic research. Ms. Vyshniakova conducts autopsies in the field. According to Pavel Gol’din, this is the dirtiest part of the work, but it is indispensable because some things cannot be seen in a museum or in a photo, they are not written about anywhere, they can only be ‘found with your hands’. Valeriia Telizhenko and Kseniia Hulak are working on genetic research, and Oksana Vertsimakha is working on statistical calculations. Other Ukrainian researchers, such as Oksana Shatkovska, Oleksandr Kovalchuk, and Oleksiy Boldyriev, are also collaborating with the project participants in various areas.
The earliest stages of cetacean evolution (when whales still had four legs) are studied by a junior researcher, paleontologist Svitozar Davydenko. He is also the team’s chief specialist in 3D technology and 3D modeling. “I am glad that Svitozar came to us as a graduate student, and now he is already a PhD. The profession growth of this researcher is due to the project,” Pavel Gol’din added with a smile.
We also asked about the plans for the team for the near future, after the project is completed. The professor replied: “A huge amount of data was collected, the team’s digital archive contains more than 4 terabytes of information. The researchers plan to process it after the project is completed. According to Prof. Gol’din, this engaging and important work that will last for several years. This means that there will be new grants and new discoveries.
Interviewed by Svitlana Galata
