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How do organisms respond when environmental conditions become too extreme?
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Biosphere
Earth's environment includes the atmosphere, the hydrosphere, the lithosphere, and the biosphere.
When environmental conditions become extreme, organisms employ a variety of behavioral, physiological, and morphological strategies to survive. Because organisms must often withstand the full range of conditions within their habitat, their responses are critical for avoiding maladaptive stress, which can lead to disease or death.12
Behavioral and Physiological Responses
- Dormancy: Many organisms enter states of reduced metabolic activity to endure adverse conditions. This includes torpor, hibernation (to survive winter cold), and estivation (to survive heat or drought).13
- Thermoregulation: Animals may use behavioral mechanisms, such as seeking shelter or reorienting toward the sun, or physiological mechanisms, such as adjusting heart rate and blood flow, to maintain a stable body temperature.1
- Migration: Many mobile species avoid extreme conditions by moving to more suitable environments, such as latitudinal or elevational shifts.13
- Plant Adaptations: Plants may respond to stress by closing stomata to prevent water loss or by reallocating nutrients to organs in need.24
Evolutionary and Long-term Adaptation
Over time, species may undergo climatic adaptation, where genetic changes favor traits that improve survival in specific extremes, such as body shape variations for heat or cold tolerance. If a species cannot adapt or migrate, it faces the risk of extinction.567