Title: Biological Anthropological
1Biomedical Anthropology
- Biological Anthropological
- by Stanford, Allen, Anton
- Professor Bender
2Are we healthier today?
- Today
- Get vaccinated
- Live longer, more parasite free
- Children at school, often lack PE because of
budget cuts - Eat high sugar, fat foods (lack balanced diet)
- 20,000 years ago
- Grows slower
- Had stronger, lean body with more muscle than fat
- If avoided infectious disease, injury and famine
would have middle age with no worries of heart
disease, high blood pressure, diabetes and even
some types of cancer
3Biomedical anthropology and illness
- Illness is a product of our genes and culture,
our environment and evolution, the economic and
educational systems we live under, and the things
we eat - Biomedical anthropology deals with issues of
health and illness - Brings issues of evolution, human variation,
genetics to the study of medically related
phenomena - Biomedical anthropology is like cultural medical
anthropology in its comparative outlook and its
attempt to understand illness in the context of
specific cultural environments
4Epidemiology Basic tools
- Looks to understand the expression of disease at
the population level - So does epidemiology quantitative study of the
occurrence and cause of disease in a population - Compared to anthropologist, they are
number-crunchers - Rate Events/population at risk (usually denoted
per 1,000 individuals, or 1,000,000 for rare
diseases) - Mortality rates are measures of the probability
of dying within a population over a given period
of time - Incidence rate (Number of new cases of a
disease/Total population) / period of time
(usually a year) - Prevalence rate total number of cases of a
disease at a given time / total population - Prevalence rate is a function of both incidence
and duration - HIV / AIDs and new drugs
5Epidemiological transitions
- Epidemiological transitions describe changes in
patterns of disease and mortality in developed
countries - In less developed socieities, most deaths are
caused by infectious disease - In developed societies, most deaths are caused by
chronic diseases of old age - Big 3 for US in 2000 heart disease, cancer,
stroke (60 of deaths) - In 1900 they were 16
- Armelagos (1997) second epidemiological
transition came with agriculture and increase of
people living in small area
6Biocultural evolutionary approaches to disease
- Biocultural approach behavior is shaped by both
evolutionary and cultural histories - Behavior influences expression of disease at both
the individual and population level - Anorexia nervosa (prevalence rate 0.5-1.0, about
90 are female) - Deals with ideal female attractiveness
- Biological factors
- Anorexia in Hong Kong females lack the fat
phobia factor, a Westernized issue
7The evolutionary approach
- Defenses versus defects
- Defect results from the disease process itself
- Defense part of the bodys attempt to fight the
disease - Example, pale person with pneumonia
- Defect darkening of the skin color, due to
reduced hemoglobin - Defense cough, to eject materials from the
throat and lungs - Infection and arms races
- Pathogens infectious agents (bacteria and
viruses) - As our bodies build defenses, so too does theirs
- Antibiotic resistance in bacteria
8The evolutionary approach
- Environmental mismatch
- Mismatch between forager lifestyle evolved for
and one we live - Fatty diets, low reproductive rates, and noise
- Pleiotropic gene effects
- Genes (and mutations) that did not lead to
adaptations in past environments but since we
live longer they may now be expressed, such as
Alzheimer disease and cancer - Design compromises
- Back pain, due to S-shaped, combined with
sedentary lifestyle - Causes 50-80 of all people in industrialized
societies suffer from back pain at some time in
their life
9Birth, growth and aging
- Human childbirth
- 4 million births in US in 2000, 90 occurred in
hospitals - In 2001, 24.4 were Cesarean
- In 1900, only 5 of US births occurred in a
hospital because it was so much more likely to
get an infectious disease when there - Human females are not much larger than female
chimpanzees, yet infant humans brains are the
size of adult chimpanzees - Could not evolve a larger pelvis, because it is
inefficient in bipedals - Tight fit between infants head and moms pelvis
- Infant has to twist to be delivered, umbilical
cord can get twisted
10Birth, growth and aging
- Traditional cultures uses midwife
- Cross-cultural studies show almost all women have
emotional reactions to onset of childbirth and
seek assistance - Biocultural adaptation increases chance of
successful birth - Besides supporting the newborn through the
contractions and birth canal, also emotional
support for mother - This support is often lacking
in contemporary hospitals - Is this changing?
11Birth, growth and aging
- Auxology study of patterns of human growth
- Patterns of growth that emerge under different
environmental conditions can provide us with
clear examples of biological plasticity - What environmental conditions can speedup/ slow
growth cycles?
12Birth, growth and aging
- Altitude, food, and stressors can change growth
rates - Can be seen as context of nongenetic adaptation
(anthropological) - Lack of food, heavy infectious disease load, and
pollution - Can be seen as any change is seen as evidence of
ill health (medical) - Biomedical sees it as a combination
- Stages of human growth
- Prenatal (gestational) stage from conception to
birth - Embryonic stage (first 8 weeks) fertilized ovum
increases 275,000 times - During rest of pregnancy (fetal period) growth
continues at about 90 times the initial weight (8
week mark) PER WEEK - Fetal alcohol syndrome (FAS) and excessive noise
in the environment can reduced/affect prenatal
growth and development
13Birth, growth and aging
- Stages of human growth
- Infancy, Juvenile stage, Adolescence and
Adulthood - Infancy birth to appearance of first permanent
tooth (5-6) - Juvenile stage lasts until the eruption of the
last permanent tooth (M3, age 15-25) - Adulthood follows, after wisdom tooth
- In primates there is very much variation in the
patterns of growth and development, and length of
stages
14Birth, growth and aging
- Stages of human growth
- Adolescence begins at puberty literally
development of pubic hair - Period of rapid growth and maturation of the body
- Tremendously variable between and within
populations - Happens sooner in industrial societies
- Juvenile periods are longest in highly
social mammals - Have most of brain mass at 6-7 but grey
matter growth at adolescence
15The secular trend in growth
- Since collecting data in 18th century girls and
boys are growing larger and maturing more rapidly
in industrialized countries with each passing
decade - Better nutrition
- Reduction of impact of infectious disease
- Used migration study to see impact of
variables - Even tends to obscure variation within
populations by socioeconomic factors
(can still be seen in extreme cases)
16Menarche and menopause
- Decrease in menarche girls first menstrual
period - From 180s until the 1970s Westernized populations
dropped from around 16-17 years to 12-13 years - What do you think can affect this?
- Menopause end of menstrual period
- Only humans have a significant life span beyond
this period - All human females ages are produced around 5th
month of gestation - Birth 2,000,000
- Puberty 400,000
- Ovulation 400 mature
- Grandmothering hypothesis
17Aging
- Maximum lifespan potential is 120 years
- Senescence starts much earlier
- As young as 20, and steeper between 40-50
- DNA replication/ mutations
- Cataracts and osteoporosis
- Free radicals molecules with at least one
unpaired electron - Vitamins C and E help this
- In wild most animals die from something other
than old age - Pleiotrophy traits different expressions at
different times
18Human variation and health skin color
- Skin has several functions
- Fluid barrier
- Keeping body protected from most chemicals in the
environment - Thermoregulation
- Metabolism of various vitamins
- What colors the skin
- Oxidized hemoglobine red
- Carotene yellow
- Melanin dark pigment
19(Dis)Advantages of light dark skin color
- Sunburn and skin cancer
- UVR can cause sunburn which is not only painful
but may interfer with the cooling of the body,
and lead to wounds - Most skin cancer, while uncomfortable, are benign
- Malignant melanoma spreads easily throughout the
body - Melanin blocks or filters out incoming UV rays
- Vitamin D Synthesis
- Essential compound in calcium metabolism
- Found in large quantities in some fish oils and
lesser degree in eggs and butter - Can get from sun
- Deficient can lead to rickets (highest in cities)
- Dark skin takes 6 times longer to make vitamin D
as light skin - Cold weather requires covering skin, reducing
intake of sunlight - Folate (Folic Acid) is a B vitamin essential
for DNA synthesis and cell replication - Exposure to UVR breaks down folate
- Too little folate causes neural tube birth
defects in developing embryo
20Infectious disease and biocultural evolution
- Infectious diseases are those in which a
biological agent, or pathogen, parasitizes or
infects a host - Are classified by modes of transmission
- Sexually transmitted
- Airborne
- Waterborne
- Etc.
- Or by organ system infected
- Respiratory infections
- Encephalitis
- Digestive tract food poisoning
- Some can only survive when in host, others for
awhile outside - Some have single host species lifecycle, others
multiple species lifecycles
21Human behavior spread of infectious disease
- Food preparation practices
- Toiletry habits
- Sex practices
- Whether one spends time in proximity to large
numbers of adults or children - Overall nutritional health and well being
- People who are weakened by food shortage,
starvation, or another disease are especially
vulnerable to infectious illness - Sharing a communal cup (or water source)
- Agriculture more people closer together
- Incubation time (time to see symptoms)
- Standing pools of water parasites
- Mobility and migration disease on the move
22Infectious disease evolutionary arms race
- For past 50 years seemed science getting jump on
infectious disease - Now HIV, AIDs, other STDs and antibiotic
resistant bacteria - Immune system
- Main line of defense in fight against infectious
disease - Must be able to distinguish itself from nonself
- Antigens whole/part of an invading organism
that prompts a response - Antibodies proteins formed by immune system to
bind to and neutralize invading antigens - Vaccination exposure to killed or inactivated
form of an antigen - Believe to have been devised in Turkish Empire
- Introduced to western civilization in 18th
century - Quarantine isolation from exposure
- Evolutionary adaptations enzymes (lysozymes)
attack cell wall structure of some bacteria - Found in high concentrations in the tear ducts,
salivary glands, and other sites of bacterial
invasion
23Diet and disease
- Cholesterol is needed in synthesis of may steroid
hormones - Carbohydrates, fat, and proteins are all sources
of energy - Proteins for tissue growth
- Fatty acids for building and supporting nerve
tissue - Vitamins
- Inorganic materials such as iron and zinc
- Paleolithic diet was more varied
- Agriculture less variation
24Agriculture and nutrition
- With agriculture came creation of stratified
societies - More nutritional deficiencies in lower classes
- Evidence of malnutrition, especially in cities
- Unbalanced diets
- Agriculture and abundance
- Nutritional excess
- Bodies set to store rare treats that are needed
for proper function - Thrifty genotype efficient in storing food in
fat - Non-western people who more likely to get fat
on westernized diet - More likely for diabetes (especially type-2)
- Actually were BETTER adapted to famine and lived
longer off of feast period
25Comparison Paleolithic / contemporary diet