Universal scaling across biochemical networks on Earth

Area of Science:

• Biochemistry
• Network Science
• Systems Biology
• Ecology

Background:

• Network science has deepened understanding of organismal metabolism and ecosystem organization.
• Its application to planetary-scale biochemistry remains largely unexplored.

Purpose of the Study:

• To characterize planetary-scale biochemistry using network science.
• To uncover universal scaling laws in biochemical networks across organizational levels.
• To investigate the origins of biological scaling and its relation to evolutionary history.

Main Methods:

• Construction of biochemical networks from a global database of 28,146 genomes/metagenomes and 8,658 biochemical reactions.
• Analysis of scaling laws governing biochemical diversity and network structure.
• Comparison of real biological networks with random networks to identify emergent properties.
• Topological analysis of biochemical networks for distinguishing evolutionary domains.

Main Results:

• Identification of shared scaling laws in biochemical networks from individuals to the biosphere.
• Demonstration that biological scaling arises from the specific structure of selected reactions, not just chemistry.
• Quantitative distinction of biochemical network topologies for the three domains of life with >80% accuracy.
• Prediction of evolutionary domain based on network size and average topology.

Conclusions:

• Biochemical networks exhibit a deeper level of organization than previously understood.
• Universal scaling principles govern biological organization across diverse scales.
• Network topology provides a signature for evolutionary history.