What We Talk About When We Talk About Evolution

Area of Science:

• Evolutionary biology
• Developmental biology
• Cellular and molecular biology

Background:

• Biological sciences face challenges due to extreme specialization, hindering interdisciplinary communication.
• A unifying mechanism integrating development and phylogenetic homeostasis is crucial for understanding evolution.
• Cell-cell interactions, specifically ligand-receptor signaling, offer a potential framework for this integration.

Purpose of the Study:

• To identify a unifying mechanism for evolution that bridges development and phylogenetic homeostasis.
• To explore functional homologies between disparate biological structures through the lens of cell-cell interactions.
• To elucidate the evolutionary continuum from proximate to ultimate causation.

Main Methods:

• Analysis of cell-cell interactions, focusing on ligand-receptor dynamics and downstream signaling pathways.
• Examination of structural-functional continuums at the cell-molecular level, using the lung alveolus as a model.
• Tracing structural and functional changes across ontogeny and phylogeny.

Main Results:

• Identified cell-cell interactions as a fundamental mechanism integrating development and homeostasis in evolution.
• Demonstrated functional homologies between diverse structures (e.g., lung alveolus and kidney glomerulus) via conserved signaling pathways.
• Revealed an unprecedented structural-functional continuum in lung evolution, linking cell-molecular adaptations to gas exchange efficiency.

Conclusions:

• Cell-cell interactions, particularly ligand-receptor signaling, provide a key to understanding evolutionary mechanisms.
• Tracing ontogenetic and phylogenetic changes reveals shared mechanisms driving biological stability and novelty.
• A comprehensive understanding of evolution requires integrating its unicellular origins with complex multicellular adaptations.