When we think about life on Earth, we can think of individual cases from animals to bacteria. However, astronaut biologists should consider the entire ecosystem and biosphere as well as individual organisms when studying life.
In space biology, there is growing interest in whether the life we know is a clue to the earth's special evolutionary history, or whether life is governed by more general organizational principles.
Scientists assume that if there is a general principle that can explain the characteristics common to all life on Earth, it can be universal to all life and can even have life on another planet. If "universal biology" exists, it has an important meaning that allows scientists to solve at least some of the characteristics of extraterrestrial life, to search for life outside the earth, synthetic biotechnology in the laboratory, and to solve the origin of life.
Previous research in this area has focused primarily on specific levels of organisms in organisms, such as individual organisms or ecosystem communities. This level forms a hierarchy of individuals composed of interacting molecules and individuals with which the ecosystem interacts.
The interdisciplinary team of researchers at Arizona State University (ASU) studied the hierarchy itself, focusing on the overall biosphere without focusing on individual levels in this hierarchy. Their findings have recently been published. Science progress.
"In order to understand the general principles governing biology, we have to understand how organisms are constructed at various levels as well as within a given level," says Professor Kim Hyun-joo of ASU's Beyond Center and the Earth and Space Exploration School.
Through this study, the team found that biochemistry at the level of organisms and ecosystems is governed by general organizational principles. Harrison Smith, co-author of ASU's Earth and Space Exploration School, said, "This means that there is a logic for a planetary-scale biochemical organization. Scientists have been talking about this type of logic for a long time, We have had difficulty measuring. Quantifying this can limit the way life occurs on Earth. "
For this study, the team built a biochemical network using a global database of 28,146 annotated genomes and metagenes and 8,658 cataloged biochemical reactions. In the process, they uncovered scaling laws that govern biological diversity and network structure, which are shared at the organization level across individuals, ecosystems, and biosphere.
"Quantifying the general principles of life, not limited to the tree of life or a specific ecosystem, is a challenge." By combining the tools of network science and scaling theories, we can conclude that large genomic data I was able to do that by using sets. "
The team is headed by Kim and Smith under the supervision of ASU Space Exploration School and Sara Walker of Beyond Center, with Cole Mathis of Beyond Center, ASU Physics Department (now Glasgow University), Jason Raymond District and Space Exploration School.
"By understanding the organizational principles of biochemistry on a global scale, we can understand how life works as a planetary process," Walker says. "The ability to more accurately identify the universal properties of life on earth will provide space biologists with new quantitative tools that will aid in the search of other world labs or alien life forms"
Interdisciplinary research has found that cell networks find the optimal point between stability and adaptability.
Kim, Hyun-Joo, and others, universal scaling through biochemical networks on Earth, Science progress (2019). DOI: 10.1126 / sciadv.aau0149