human adaptability human adaptability definitions types of adaptation adaptation to climate

HUMANADAPTABILITY

HUMANADAPTABILITY

DefinitionsTypes of Adaptation

Adaptation to Climate

Stress -- a condition that disturbs the normal functioning of the organism

Fitness -- reproductive success; the ability to produce viable offspring who themselves reproduce, with minimal energy expenditure.

Basal Metabolic Rate -- the amount of energy the body needs to maintain its function in an absolute resting condition

Functional Adaptation -- involves changes in the body either as independent systems or in the organism as a whole

• Acclimatization - long term• Acclimation - short term• Habituation - gradual reduction

Cultural Adaptation -- non-biological changes passed on as a part of socialization

Genetic Adaptation --

the process whereby a population becomes genetically fine-tuned to the environment.

Controversy as to whether this form of adaptation exists in Homo sapiens.

• skin color• birth weight• O2 absorption• lung capacity

ArcticMountain

Tundra

Deciduous

Rainforest

Grassland

SavannaDesertChaparral

Mountainsof the World

Main Difficulties -- • getting enough O2• cold; increased radiation• low biodiversity

Biological Adaptations -- • increased pulmonary capacity• increased RBC production

Cultural Adaptations -- • use of adapted animals• high carbohydrate diet• use of cocoa

Additional responses -- • slowed maturation• reduced sexual dimorphism• resting HR goes from 70 beats/min to

105 beats/min• light sensitivity decreases• memory & recall diminish• food preferences for sugars• anorexia and weight loss

Arctic Regionsof the World

Main Difficulties -- • cold• low biodiversity• long periods of darkness

Biological Adaptations -- • shivering responses; increase BMR• non-shivering thermogenesis• long noses; body form• brown adipose tissue

Cultural Adaptations -- • clothes, fire, & housing• high protein diet

Bergman’s Rule -- • in bodies of the same shape, the

larger has less surface area

• increased amount of metabolic tissue therefore internal heat gain is greater

Increase BMR -

• basic level of heat production by the body based on chemical reactions of metabolism

• muscular activity can raise BMR by 5 times

• several hormones raise BMR such as epinephrine, norepinephrine, and thyroxine

• dietary intake causes an increase in metabolic rate as body works to digest food

Core Shell Model - • vasoconstriction causes blood to

pool and conserve organ heat

• vasodilation increases the flow

Desertsof the World

Main Difficulties -- • hot & dry• lack of water• lack of biodiversity

Biological Adaptations -- • lower pulse rate• decreased salt output in sweat• body form• highly tanable skin

Cultural Adaptations -- • houses of adobe, cloth• clothing aids evaporation• activity patterns

Allen’s Rule -- keeping mass constant, increasing surface area with long, linear form

Skin Color -- • brunette tanable

• UV radiation, vitamin D production

• melanin; conduction

Rainforestsof the World

Main Difficulties -- • heat loss is difficult• low animal biodiversity

Biological Adaptations -- • highly tanable skin• ready onset of sweating• short broad nose

Cultural Adaptations -- • live near water• little clothing• low salt intake• reduced activity levels

“black body” radiation

Acclimatization to Rainforest -- • increased peripheral heat

conductance

• high vasodilation & blood flow• lower sweat output• enhanced sodium resorption