[The adaptive-compensatory reactions in adjusting to space flights]

Area of Science:

• Evolutionary biology
• Space medicine
• Human physiology

Background:

• Life's evolution demonstrates adaptation to environmental pressures, including gravity.
• Understanding adaptation to novel environments is crucial for space exploration.
• The concept of adaptation versus compensation offers insights into physiological changes.

Purpose of the Study:

• To present an evolutionary model for understanding human adaptation to weightlessness.
• To define a 4-step scheme for adaptation to space mission environments.
• To identify strategies for mitigating the challenges of readaptation to Earth's gravity.

Main Methods:

• An evolutionary approach to model life's adaptation to gravity.
• Analogical reasoning comparing aquatic adaptation to weightlessness.
• A 4-step framework detailing adaptation to space and return to Earth.

Main Results:

• Hypogravity adaptation parallels the transition of terrestrial animals to aquatic environments.
• A 4-step adaptation process is outlined: preadaptation, compensation, norm formation, and readaptation.
• The 'price' of adaptation, or readaptation challenges, can be reduced through mission support.

Conclusions:

• An evolutionary perspective provides a model for understanding human adaptation to space.
• The proposed 4-step scheme aids in planning for space missions and astronaut health.
• Reducing the physiological cost of readaptation is a key goal for long-duration spaceflight.