Stress-induced variation in evolution: from behavioural plasticity to genetic assimilation

Area of Science:

• Evolutionary biology
• Developmental biology
• Stress physiology

Background:

• Extreme environments are linked to phenotypic evolution, but mechanisms remain unclear.
• Understanding stress-induced variation is crucial for evolutionary insights.

Purpose of the Study:

• To elucidate the mechanisms linking extreme environments to evolutionary adaptation.
• To highlight the role of stress-induced variation in evolutionary processes.

Main Methods:

• Review of recent studies on stress, variation, and evolution.
• Analysis of neuroendocrinological, morphological, and behavioral systems under stress.
• Examination of developmental plasticity and inheritance mechanisms.

Main Results:

• Stressful environments reduce regulatory system integration, allowing for accommodation of variation.
• Stress-induced variation is often directional, channeled by ontogenetic pathways, facilitating adaptive evolution.
• Transgenerational inheritance of stress responses aids genetic assimilation and evolutionary persistence.

Conclusions:

• Developmental systems accommodate stress-induced variation, enabling organismal memory and assimilation.
• Phenotypic and genetic variance increase under stress, often directed by existing pathways.
• Inherited stress responses link individual adaptability to evolutionary adaptation, ensuring persistence of strategies.