The Evolution of Calcification in Reef-Building Corals

Corals build the structural foundation of coral reefs, one of the most diverse and productive ecosystems on our planet. Although the process of coral calcification that allows corals to build these immense structures has been extensively investigated, we still know little about the evolutionary processes that allowed the soft-bodied ancestor of corals to become the ecosystem builders they are today. Using a combination of phylogenomics, proteomics, and immunohistochemistry, we show that scleractinian corals likely acquired the ability to calcify sometime between similar to 308 and similar to 265 Ma through a combination of lineage-specific gene duplications and the co-option of existing genes to the calcification process. Our results suggest that coral calcification did not require extensive evolutionary changes, but rather few coral-specific gene duplications and a series of small, gradual optimizations of ancestral proteins and their co-option to the calcification process.

Automated summary

The study suggests that scleractinian corals likely acquired the ability to calcify between approximately 308 and 265 million years ago through lineage-specific gene duplications and the co-option of existing genes. The evolution of coral calcification did not require extensive changes, but rather a few coral-specific gene duplications and gradual optimizations of ancestral proteins.