Human Adaptation

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Human Adaptation
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Adaptation

• a beneficial adjustment to a particular
  environment and/or stress, either by an
  individual or evolutionarily by a population.
• Stress Any factor which interferes with the
  normal limits of operation of an organism.
• Homeostasis The maintenance of normal limits of
  body functioning.

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Adaptation

• Cultural Adaptation
• Biological Adaptation
• Genetic (Natural Selection)
• Acquired/Physiological (Plasticity)
• Temporary (Acclimation/Acclimatization)
• Permanent (Developmental Acclimatization)

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Human Adaptations to Cold Stress

• Increase Heat Production
• Enhance Heat Retention
• Vasoconstriction narrowing of blood vessels,
  reducing blood flow and heat loss.
• Vasodilation opening of blood vessels,
  increasing blood flow and heat loss.

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Lewis Hunting Reaction
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Acclimatization and Cultural Adaptations to Cold
Stress
Netsilik
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Human Adaptations to Heat Stress

• Biological
• Sweating
• Vasodilation
• also radiation, conduction, and evaporation
• Cultural

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Climate and Morphological Variation

• Bergmanns Rule
• Allens Rule

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Boas and Head Shape
Cranial/Cephalic Index
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tummy time
Plagiocephaly and SIDS Prevention
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Human Adaptations to Multiple StressesHigh
Altitude

• cold, wind, solar radiation, low humidity, less
  food, rough terrain,
• and most important hypoxia

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Initial Temporary Responses to Hypoxia

• Temporary increase in respiration rate
• Temporary increase in heart rate
• Red blood cell production increases

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Physical Growth in High-Altitude Populations

• Slowed growth and maturation
• Increased lung and heart capacity
• Larger chest size
• More efficient diffusion of O2 from blood to body
  tissue

Distance curves for chest circumference for
high-altitude Peruvian Indian populations.
Coca Leaf
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Malnutrition
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Obesity (BMI gt 30) in U.S. Adults2006
Source CDC