The document discusses how human evolution and health have been shaped by dietary and lifestyle changes from hunter-gatherer societies to the development of agriculture and industry. It describes how early humans were well-adapted to high activity lifestyles and varied diets high in nutrients, whereas modern diets and more sedentary lives have mismatched our biology and led to increased risk of chronic diseases. The application of evolutionary theory in medicine emphasizes behavior modification and prevention over treatment to address the underlying causes of disease.

1. Introduction to
Evolutionary Theory
Austin Zakari, MA
Ant 306

2. Terminology
• Evolutionary Medicine – Application of principles of
evolutionary theory to the practice and research of medicine
• Environment of evolutionary adaptation – A time when the
traits that organisms now possess were acquired
• Macronutrients – These refer to carbohydrates, protein & fat
• Needed in large quantities to support energy and fundamental
body structures
• Micronutrients – Vitamins and Minerals
• Phytochemicals – Nonnutritive but biologically active
compounds found in plants – antioxidant, anti-inflammatory
properties, etc.

3. The Human Genome
• Modern humans form their genotypes from over a billion
years of evolutionary experience
• Humans and chimpanzees differ genetically by just 1.6%
• Europeans are more closely related to Cro-Magnon
ancestors than modern Africans or Asians
• Homo sapiens sapiens became widespread about 35,000
years ago – from a genetic standpoint we are still late
Paleolithic pre-agricultural hunter gatherers
• Metabolic demands of bipedalism along with expanding brain
size placed a premium on foods and created a mismatch
between biology and modern lifestyle

4. Populations in
Transition
• Gatherer- Hunters have much lower risks of chronic disease
• Had small balanced populations/ growth was slow and stable
• Egalitarian societies, little differences in economic status
• Limited number of diseases – Organisms (lice, worms etc) and
zoonotics (diseases spread by animals); viruses are unclear but thought
to have been less common and not able to be epidemics
• Endurance activities of hunting and gathering created both strength and
stamina in both sexes
• Evidence of both alcohol and tobacco but very limited – probably not
enough to impact health overall

5. Preagricultural Diet
Transitioned from foraging to food production approx. 10,000 years ago
• Had a varied diet depending on region – energy expenditure to acquire food is considered to
be moderate
• Periods of scarcity and abundance in their diet
•
• Ate wild foods that were diverse in both plant and animal matter – this abundance and
diversity of plant foods created a mix of phytochemicals that act synergistically to lower the
risk of chronic disease
• Consumed almost no grains, no dairy foods, limited amounts of fat and very little salt
• Obtained more potassium than sodium from food – average about 75% less sodium in diet then
American average
• Even though no dairy foods had higher intake of calcium then generally consumed today
• Diets were high in fiber, micronutrients and protein
• Studies show approximately 34% of diet from protein compared to 15% of calories from protein in
today’s diet
• Lean, grass fed wild game
• Simple sugars very limited (honey) and seasonal

6. Agricultural & Animal Domestication
• Establishment of permanent settlements increased population density
• Reduced the variety of plants grown
• Grains were easily grown by early farmers
• Increased energy expenditure however skeletal remains of hunter- gatherers were
stronger and more muscular – suggests that while agriculturists worked longer
hours intermittent peak demand coupled with intensity is more important than
number of hours works for development of muscularity
• Shift in disease exposure as prior only men exposed to zoonotic diseases through
hunting/ butchering, with domestication of animals alterations in labor and
exposure cause increase in distribution of diseases
• Resulted in fewer micronutrient rich foods and a decline in dietary diversity
• Primary food production can generate surpluses however, nutritional deficiencies from
famine (drought, blight, etc) and reliance on single crops (such as cereal grains) can occur
• Humans are the only primates (not living in captivity) that consume cereal grains
• When a population becomes malnourished it is more susceptible to infection and disease

7. Health Consequences to
Domestication
• Increased signs of
malnutrition, undernutrition, anemia, cavities, growth
retardation are seen in skeletal remains of agricultural
sites as compared to gatherer- hunter sites
• Some controversy as to whether there was more
disease or simply more people in the agricultural sites
because of population growth however, generally
thought that the transition to agriculture brought poor
health (at the onset)
• Agriculture/ Domestication has been connected to the
emergence of social stratification
• Political/ economic power related to control over key
resources
• Border conflicts and wars over resources
• Workers as compared to owners still suffer the affects of
more energy expenditure (working the land), less nutrient

8. Shifting towards
Industrialization
• Food surpluses and high infant mortality allowed for reduced birth spacing; can
wean infants earlier
• Increased exposure to parasitic disease spread by human/ animal
waste, contaminated water by human/ animal waste, increased exposure to soil
dwelling microbes due to cultivating land and crops
• Herding/domestication of animals caused increase in zoonotic diseases – such as
chicken pox, measles, tuberculosis & many other common childhood diseases
today
• Transmission can go from animal to human or vice versa
• Increased trading causes trade routes to become global distributors of disease
amongst peoples/ animals of different world regions
• Ex: Black death or Bubonic plague
• Mongolian/ Central Asian rodents – carriers
• Trade ships transport to new areas throughout the world
• Caused 3 pandemics of plague (defined as 35-90% mortality)
• Claimed siblings of William Shakespeare; caused his theater to shut down during
outbreaks
• 1907 plague kills 1.3 million people in India
• Caused quarantines, seen as punishment from God

10. Industrialization
• Key social changes in human populations are the major cause of disease rates and
exposure to infectious diseases –
• European expansionism and colonialism produced significant changes in human
disease
• More people exposed to new diseases/ no defenses
• Spread of disease easier in crowded conditions; larger populations spread disease
to endemic form
• Forms of birth control practiced – allowed for lower infant mortality
• Urban living, allowed for novel diseases to spread amongst populations that had
little resistance to them such as syphilis and cholera
• Large populations in urban centers was comparatively late in human
history, therefore humans have been exposed to endemic diseases for a relatively
short time consequently, genetic adaptation to specific pathogens is unlikely
• Until the late 1920’s infectious disease was the number one killer in the United
States

11. Industrialization and Diet
• Diets rich in processed carbohydrates, dairy products, fats and salt
• Sugar, fat and salt biologically pleasurable, however our bodies adapted to
diets with very limited amounts of these
• Livestock fed grain and calorie rich diets (not grass fed) leading to meats
with a high percentage of saturated fats
• Diversity of fruits and vegetables, less therefore fewer varieties of
phytochemicals and nutrients
• Eat extremely efficient, calorically concentrated foods
• Cereal grains are nutrient dense and their introduction to our diets allowed
for fruits and vegetables to be lowered to about 20% or less of our total
calories
• Calorie Loaded beverages, and less fiber in foods cause a higher, faster
consumption of calories
• Fiber and complex carbohydrates are shown to lower blood glucose levels

12. Diseases of Civilization
• 75% of deaths in Western nations are from chronic degenerative diseases
(diseases of civilization)
• Estimated that 7-10% of daily energy intake (calories) for an average adult
American is provided by alcohol
• Before 1940’s diabetes was rare in American Indians
• Today they have some of the highest rates in the world
• Obesity and diabetes one of the first disorders to afflict “newcomers” who undergo economic
development – whether through immigration or modernization
• Predicted that by 2025 globally 300 million adults will live with Type 2 Diabetes
• In the U.S. diabetes costs about 100 billion dollars annually and accounts for 15% of all of
the healthcare costs of all diseases combined
• Cancers – 60%+ of cancers are the result of environmental influences and therefore
preventable
• Studies indicate that although we live longer, degenerative diseases are not
necessarily consequences of living longer
• More than half the people who ever lived beyond the age of 65 are alive today!!

13. Medical Treatment or
Behavioral Modification?
• Medical education focuses on the structure and function of the body –
Engineering approach
• Like a car, once understood can be assembled, disassembled as needed
• Successful in many ways but also deficient when conceptualizing overall
human health
• Thomas McKeown – attributes decline in mortality and overall better
health in a small part to vaccines and medicines but mainly to
decreased exposure to microorganisms, especially prior to the 20th
century
• Purification of water
• Sewage disposal
• Improved food preparation and preservation
• Pasteurization of milk
• Better hygiene accounts for 1/5 of the total reduction of mortality
• Improvement in nutrition allowed the body to resist infectious diseases

14. Determinants of Health
• Thomas McKeown says “The best vaccine against common infectious disease is an adequate
diet”
• Infection and malnutrition still leading killers in 4th world today
• 40% of the worldwide population lives on $2 a day or less
• Do you agree with this?
• Improvements in health can be attributed to:
• Food, hygiene and medical intervention (in that order)
Does this sound feasible?
• Behavior Modification is why the improvements in mortality due to infectious disease have
become permanent
• Is this same premise possible when applied to today’s killer diseases?
• Most diseases have individual elements that may be controlled (such as smoking, exercise, diet, etc)
• Common medical thinking asserts we are “ill and made well …rather than we are well and made ill”
• Services, education and research are key to behavior modification
• Some suggest research should focus on resistant populations rather than susceptible ones
• Medical resources should be focused on prevention rather than acute care or managing chronic
disease

15. The Contributions of Medical
Anthropology
• Believes in a holistic and symbiotic relationship with the body and
environment
• What does this mean to you?
• Brings a broader perspective by focusing on human beings
interacting with their sociocultural, political, ecological and global
environments
• Can be a crucial bridge between social theory and policy
• Use qualitative methods (ethnography, etc) to reveal deeper
threads of systemic injustices
• Employ methodologies that take into account cultures as whole
systems
• Have the opportunity to be advocates as well as researchers

16. BUZZWORDS……..
• Macronutrients
• Micronutrients
• Phytochemicals
• Morbidity
• Mortality
• Holistic
• Symbiotic