ANTHRO EXAM 2 13-16

What is biological adaptation?

Process of change in physiology or morphology
Resulting from an altered environment
Improves evolutionary fitness (survival and reproduction)

Process depends on degree and timing of exposure

Timescales of Adaptation Model ( time matches the mode of adaptation)

Seconds/Hours allostasis

Days/Months/Seasons Acclimatization

Years

Developmental Adaptation
Decades

Centuries Genetic Adaptation

What is metabolic health?

• A person’s risk of developing cardiovascular disease
and/or adult-onset (type II) diabetes mellitus

Poor metabolic health is characterized by

• Hypertension

•  Dyslipidemia

• Hyperglycemia

• Subclinical inflammation

• obesity 

Disadvantage of BMI as indicator of health

Incorporates body mass, not body fatness

adipose tissue type

SAT & VAT

Subcutaneous adipose tissue (SAT)

• Distributed on hips, thighs and
buttocks
• Produces fewer molecules that
stimulate inflammation

Visceral adipose tissue (VAT)

• Located closer to important
organs
• Produces more inflammatory
molecules

Dietary adequacy

• Extent to which food intake fulfills one’s nutritional requirements
• Intake vs. requirement
• Macronutrients: protein, carbohydrates, fats
• Micronutrients: vitamins and minerals

Homeostasis

• The state of steady internal physical and chemical conditions
maintained by living systems

Allostasis

• The regulation of internal biology through rapid changes in
physiology

Epidemiological Transition

The shift from infectious diseases to non-infectious diseases as primary causes of mortality

Pre-transition”

• High death rate due to epidemics,
childhood infectious disease
• Low life expectancy

“Post-transition”

• Improved sanitation, public health,
and medical technology -> reduced
infectious disease rate

increases life expectancy

Characteristics of the acute stress response

Rapid mobilization of energy from storage sites (like body fat)
• Inhibition of future energy storage( Blocking the breakdown and digestion of food)
• Increase in breathing rate, blood pressure and heart rate
• Halt energy-expensive processes (Growth, reproduction, tissue repair)

The Autonomic Nervous System

Regulates unconscious bodily functions such as (Heart rate, blushing, goosebumps, digestion, etc)

Sympathetic nervoussystem (SNS)

• Activated by stress

Parasympathetic nervous system (PNS)

• Turned off by stress

Sympathetic Nervous System

In charge of the “fight or flight” response

Produces epinephrine (adrenaline) and norepinephrine

Epinephrine

increases blood flow to the muscles and heart

Norepinephrine

regulates blood flow through the blood vessels

Hypothalamus-Pituitary-Adrenal Axis

• Brain processes psychosocial stress
• Causes the hypothalamus to produce corticotropin releasing hormone (CRH)
• CRH travels to the pituitary gland
• Pituitary gland produces adrenocorticotropic hormone
(ACTH, a.k.a. corticotropin)
• ACTH travels to the adrenal glands
• The adrenals produce glucocorticoids, such as cortisol

Cortisol

a stress hormone and a metabolic hormone

The health effects of chronic glucocorticoid exposure

• Cardiovascular effects (Dysfunction of endothelium of blood vessels)

• Gastrointestinal effects(Irritable bowel syndrome, sensitivity to acid, changes in
composition of gut microbiome)

• Metabolic effects( Increased craving of calorie-dense foods and Increase deposition of visceral adipose tissue (VAT))

• Immune effects (Suppress cells that fight infections)

types of wavelengths

UVA, UVB, UVC (UVB leads to skin damage/cancer)

Risks of UV exposure

Short term – Sunburn
Long term – premature aging, skin cancer, eye diseases

Degrade folate (Folate – vitamin responsible for red blood cell formation and
cell growth and function)

benefits of UV exposure

Vitamin D production (helps your body absorb calcium and phosphorus to assist in bone growth
maintenance)

Melanin

chemical compound, produced by melanocytes (cells), hair, skin, pupils/irises, parts of your brain and inner ea

3 types of melanin

Eumelanin (black and brown variants) - responsible for dark
pigmentation of skin, eyes, and hair

• Pheomelanin- responsible for reddish pigmentation lips and nipples

• Neuromelanin – pigments your neurons (you never see these
colors)

MC1R gene

Regulates production of melanocortin 1 receptor (related to normal pigmentation)

• When activated, stimulates production of eumelanin – without this signal, melanocyte produces pheomelanin (not useful against UVR)

• Variation in MC1R associated with varying amounts of
eumelanin

Tanning response

When skin produces eumelanin pigment as a result of seasonal high UVR exposure
• The outcome of UV-induced stress
• Regulated by melanocortins (A group of hormones, can be found in skin cells (melanocytes))

Bergmann’s Rule

•Larger animals are found in colder environments and smaller animals are found in warmer regions

Allen’s Rule

•Animals adapted to warm climates will have longer limbs and appendages than animals adapted to cold climates

Vasoconstriction

Constriction of blood vessels close to skin surface
• Reduce heat loss

vasodilation

is the widening of blood vessels,

Biological Adaptations to Cold Stress

o Allostatic Responses to Cold Stress
o Acclimatization to Cold Stress
o Developmental Adaptation to Cold Stress
o Genetic Adaptations to Cold Stress

Brown Adipose Tissue (BAT)

produces energy/warmth