If we reflect on earthly life, we usually recall specific examples - from animals to bacteria. But when it comes to the work of astrobiologists, they have to take into account not only individual organisms, but the ecosystem and the biosphere as a whole.
Researchers want to understand whether life is a freak of an exclusively terrestrial evolution or there are more general organizational principles. If the latter is true, then there should be universal rules not only for life on Earth, but also on other planets. The existence of a universal biology would greatly influence the process of searching for alien representatives. In addition, it would be possible to predict at least a certain part of the properties of life on other planets.
The graph displays the biosphere, ecosystems and the individual biochemistry of organisms in the form of connecting molecules participating in general reactions. Here you can see that various scaling laws are common at different levels of biological organization.
Previous studies in a particular field have focused on specific levels of organization in biology, such as individual organisms or ecological communities. Levels create a hierarchy where species consist of contacting molecules, and ecosystems consist of interacting individuals. The new study decided to focus not on individual levels, but on the hierarchy itself (the biosphere as a whole). If you want to study the principles governing biology, then you need to know how living systems are organized at different levels, and not at one.
It turned out that biochemistry (both at the level of organisms and ecosystems) is governed by general organizational principles. That is, in the organization of biochemistry of planetary scale there is a sense. For analysis, scientists have created biochemical networks using a global database of 28,246 annotated genomes and metagenomes and 8,658 cataloged biochemical reactions. They also revealed scaling laws governing biochemical diversity and network structure.
Quantifying the general principles of life is a difficult task. Its solution consisted in a combination of tools from network science and scaling theory, using large sets of genomic data from the catalog. Awareness of the principles of the organization of biochemistry on a global scale allows us to understand the functionality of life in the form of a planetary process. So, it will be much easier to find life on another planet.
