How old are you? Genet age estimates in a clonal animal

Area of Science:

• Marine biology
• Ecology
• Genetics

Background:

• Foundation species like corals are long-lived and clonal, with genets potentially existing for centuries.
• Estimating the age of clonal organisms is challenging as size does not correlate with age.
• Demographic models lack crucial age data for clonal species, hindering predictions of resilience to climate change.

Purpose of the Study:

• To correlate somatic mutations with genet age in corals.
• To provide preliminary estimates of genet age in the endangered coral, Acropora palmata.
• To assess the resilience capacity of A. palmata to environmental changes.

Main Methods:

• Somatic mutations were observed at five microsatellite loci in 3352 samples of A. palmata.
• Mutation rates were estimated using colony growth rates and sea level changes affecting habitat availability.
• Genet age was calculated based on observed mutations and estimated mutation rates.

Main Results:

• 342 unique mutations were identified across 147 genets of A. palmata.
• Estimated genet ages ranged from 30 to 838 years (growth rate mutation rate) and 236 to 6500 years (sea level change mutation rate).
• Long-lived genets suggest a significant capacity for past environmental change tolerance.

Conclusions:

• Somatic mutations can be used to estimate genet age in colonial animals like corals.
• A. palmata genets possess substantial longevity, indicating historical resilience.
• Recent mass mortality events suggest that current environmental stressors are overwhelming the adaptive capacity of A. palmata.