Shorter telomeres precede population extinction in wild lizards

Area of Science:

• Ecology
• Molecular Biology
• Conservation Biology

Background:

• Ecologists are increasingly focused on identifying early warning signals of catastrophic extinctions.
• Species' functional responses to environmental changes offer potential for refining these warning signals.
• Telomere length (TL) analysis is a molecular tool for detecting early population decline, as telomere attrition is linked to aging and environmental stressors.

Purpose of the Study:

• To investigate proximal signals of demographic decline in common lizard (Zootoca vivipara) populations.
• To assess the relationship between telomere length and extinction risk in Zootoca vivipara populations.
• To identify telomere length as a potential biomarker for population extinction risk.

Main Methods:

• Sampling of 100 yearling common lizards from 10 natural populations along an extinction risk gradient.
• Monitoring of relative lizard abundance over 12 years in relation to environmental conditions (temperature, body growth).
• Analysis of the non-linear relationship between telomere length and population extinction risk.

Main Results:

• Relative lizard abundance significantly dropped in low-altitude populations with warmer temperatures and higher early-life body growth.
• A non-linear relationship was observed between telomere length and extinction risk.
• Populations facing high extinction risk exhibited shorter telomeres compared to non-threatened populations.

Conclusions:

• Telomere length serves as a promising biomarker for predicting population extinction risk.
• Population extinctions may be preceded by accelerated physiological aging, indicated by telomere attrition.
• Environmental stressors can accelerate aging processes, leading to population decline and extinction.