Download OUTLINES FOR CHAPTERS 4, 5, AND 6 File

OUTLINES FOR CHAPTERS 4, 5, AND 6
PHYSICAL ANTHROPOLOGY 1
SPRING 2016
CHAPTER 4 OUTLINE
1. Demes, Reproductive Isolation, and Species
a. Evolution is about groups of potentially reproducing organisms.
b. Deme refers to members of a species that produce offspring.
c. All the genetic material within a population is referred to as the gene pool.
d. The term species refers to the populations and their members that are capable of breeding with
each other and producing viable, fertile offspring.
i. Species are defined on the basis of reproductive isolation.
e. Population genetics studies change over time (or the lack of it) in gene pools.
2. Hardy-Weinberg Law: Testing the Conditions of Genetic Equilibrium
a. It is a method for studying genetic change in populations.
b. If no change is occurring within the population, gene frequencies at a locus remain the same.
c. If change is occurring, evolution is happening within the population.
3. Mutation: The Only Source of New Alleles
a. Mutation is the only source of new genetic information.
b. Mutation can be any heritable change in the structure or amount of genetic material.
c. Different types
i. Point, frameshift, transposable elements
d. Spontaneous mutations have no known cause.
e. Induced mutations are caused by environmental agents (mutagens).
f. Most mutations are harmless.
4. Natural Selection: Advantageous Characteristics, Survival, and
a. Based on Darwin’s principle that individuals with advantageous characteristics will survive and
reproduce in higher numbers (reproductive success)
b. Patterns of Natural Selection
i. Directional selection favors an extreme form of a trait.
ii. Stabilizing selection favors the average form of a trait.
iii. Disruptive selection favors individuals at both extremes.
c. Natural Selection in Animals: The Case of the Peppered Moth and Industrial Melanism
i. Numerous examples exist for natural selection in animals, such as the sea dragon and
the much studied peppered moth.
ii. The peppered moth is the best evidence of natural selection documented.
iii. The peppered moth was found in England.
iv. The peppered moth had two forms: light and dark.
v. As pollution covered trees in the moths’ habitat, the lighter peppered moths were more
easily preyed on by birds and the darker form became more prevalent.
vi. In the 1970s, stricter pollution laws again changed the moths’ habitat, and the darker
form became the easier prey; the lighter form became more common.
d. Natural Selection in Humans: Abnormal Hemoglobins and Resistance to Malaria
i. The Hemoglobin S gene causes sickle-cell anemia in humans.
ii. Individuals with the SS genotype suffer from sickle-cell anemia, an illness fatal
without medical intervention.
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CHAPTER 5 OUTLINE
1. Is Race a Valid, Biologically Meaningful Concept?
a. Brief History of the Race Concept
i. Race is the classification of human variation.
ii. Early written records do not use the idea.
iii. Some argue the race concept started during the Renaissance.
iv. Other early race concepts began in the eighteenth century.
(1) Blumenbach’s study of skulls in 1775 set a racial taxonomy.
b. Debunking the Race Concept: Franz Boas Shows that Human Biology Is Not Static
i. Franz Boas was among the first to challenge the taxonomy of human variation.
ii. Boas examined the cephalic index and found no support of racial types.
iii. This work was the foundation for a focus on biological process rather than on
typology.
c. So-Called Racial Traits Are Not Concordant
i. Robert Lewontin studied global genetic variation.
ii. Racial groups accounted for only 5–10% of variation.
iii. Most variation is among groups, not within groups.
iv. Since Lewontin’s research, a number of other genetic studies have reached the same
conclusion.
d. Human Variation: Geographic Cline, Not Racial Categories
i. Specific biological traits follow a geographical gradient (cline).
ii. Skin pigmentation is an example.
2. Life History: Growth and Development
a. The Growth Cycle: Conception through Adulthood
i. Divided into three stages: prenatal (ending with birth), postnatal (to around twelve
years of age), and adult (through senescence)
b. Prenatal Stage: Sensitive to Environmental Stress, Predictive of Adult Health
i. Pregnancy lasts nine months.
ii. Involves rapid growth and development, especially of the brain
iii. Prebirth stressors can influence diseases a person may develop later in life.
c. Postnatal Stage: The Maturing Brain, Preparing for Adulthood
i. Divided into five periods characterized by different growth velocities
ii. Development of brain, dentition, motor and cognitive skills, sexual dimorphism,
skeletal structure
iii. Environmental effects during childhood influence growth and development.
(1) Secular trends in height; changes in stature caused by environment
iv. Before adulthood, height deficits caused by growth disruption can be recovered
through a period of rapid growth.
d. Adult Stage: Aging and Senescence
i. Aging refers to social, cultural, biological events that occur over a lifetime.
ii. Senescence is a reduction of the body’s ability to respond to stress (homeostasis).
iii. Cessation of reproduction in women is called menopause.
e. Evolution of Human Life History: Food, Sex, and Strategies for Survival and Reproduction
i. Survival and adaptive success are due to food acquisition and reproduction.
ii. Humans are influenced by culture.
iii. Life history develops with human culture.
iv. Prolonged Childhood: Fat-Bodied Moms and Their Big-Brained Babies
(1) Humans have a prolonged childhood with high maternal investment
f. Grandmothering: Part of Human Adaptive Success
i. Postreproductive survival is high with humans.
ii. Women play a large role in caring for children’s children.
3. Adaptation: Meeting the Challenges of Living
a. Adaptation to the environment occurs at four levels.
i. Genetic
ii. Developmental
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iii. Physiological (acclimatization)
iv. Behavioral (culture)
b. Climate Adaptation: Living on the Margins
i. Heat Stress and Thermoregulation
(1) Body attempts to maintain core body temperature under hot conditions
through vasodilation and sweating.
(2) Humans have a strong ability to adjust to heat.
ii. Body Shape and Adaptation to Heat Stress
(1) Bergmann’s rule: Heat-adapted mammals will have higher surface-area-tobody ratios.
(2) Allen’s rule: Heat-adapted mammals will have long limbs.
(3) Rules explain variation in human body shapes going back
1.5 million years.
iii. Cold Stress and Thermoregulation
(1) The human body struggles to maintain body temperature at cold extremes
through vasoconstriction, shivering.
iv. Solar Radiation and Skin Color
(1) Best predictor of skin color is UV radiation exposure.
(2) More pigmentation is associated with high UV.
v. Solar Radiation and Vitamin D Synthesis
(1) The body needs UV radiation to synthesize vitamin D.
(2) Vitamin D is crucial in calcium absorption, bone mineralization.
(3) Deficiencies in vitamin D production can lead to bone malformations,
including malformations of the pelvis.
(4) Melanin is the primary influence on vitamin D synthesis. Depending on
environment, a person’s melanin type can be advantageous or disadvantageous.
vi. High Altitude and Access to Oxygen
(1) Humans suffer from hypoxia (lack of available oxygen) at high altitudes.
(2) The body responds through production of extra red blood cells and
hemoglobin, increasing diameter of blood vessels.
(3) Those born at high altitudes have greater lung volume and larger chest
cavities as well as the above characteristics.
c. Nutritional Adaptation: Energy, Nutrients, and Function
i. Each human body requires certain energy and nutrients to function.
(1) Basal metabolic requirement (basic body functioning)
(2) Total daily energy expenditure (energy needed for BMR plus work, exercise,
etc.)
ii. Human Nutrition Today
(1) Most populations are undernourished and consume too few calories.
(2) Efforts to combat this problem have resulted in new nutritional issues.
iii. Overnutrition and the Consequences of Dietary Excess
(1) Dietary excess is as serious a problem as dietary lack.
(2) Obesity is an increasing problem in the U.S., especially among children, as
well as in the Pacific, Europe, Middle East, Latin America, and South Africa.
(3) Obesity can lead to high cholesterol, heart disease, diabetes.
(4) May have resulted from genetic traits that allowed for conservation of
nutrition during times of famine (thrifty genotype)
(5) Examples of this thrifty genotype can be found in Native Americans in the
United States.
d. Workload Adaptation: Skeletal Homeostasis and Function
i. Bone growth is affected by disease, physiological processes, nutrition, and mechanical
forces.
ii. Wolff’s law states that bone is produced where it is needed and removed where it is
not.
iii. Activity or the lack of it can change the shape of skeletal elements.
e. Excess Activity and Reproductive Ecology
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i. Benefits of exercise are well documented.
ii. Excessive workload or exercise can interrupt female reproduction, lowering fertility
levels.
iii. Excessive workload potentially can lower birthrates in certain groups or populations.
iv. Work or exercise becomes a selective factor in evolution.
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CHAPTER 6 OUTLINE
Focus of the chapter:
What is a primate?
Primates are arboreally adapted.
Primates have dietary plasticity.
Primates are defined by a suite of traits that separate them from other mammals.
They possess a versatile skeletal structure suited to arboreal life. They have opposable thumbs for grasping
and enhanced touch and vision. Primates rely less on smell and hearing. Their dental variation allows for a
varied diet. Extensive social relationships and behaviors are combined with high parental investment in
young.
The wide variation in primate species can be divided into four groups: prosimians, New World
monkeys, Old World monkeys, and apes. Humans are grouped with the apes, though some debate exists
over how to cluster the apes within the clade. Anatomical and genetic traits are utilized in classification
systems today.
1. What Is a Primate?
a. History of classification of the order
i. Linnaeus first described the order Primates for classification
purposes.
ii. As identified by Le Gros Clark, primates have the following
traits:
(1) Primates are adapted to life in the trees (arboreal adaptation).
(2) Primates eat a variety of foods (dietary plasticity).
(3) Primates invest a lot in a few offspring (parental investment).
b. Arboreal Adaptation: Primates Live in Trees and Are Good at It
i. Primates have a unique combination of specific arboreal
adaptations.
ii. Primates Have a Versatile Skeletal Structure
(1) Clavicle acts as a strut to keep upper limbs to sides of body.
(2) Ulna and radius rotate forearm.
(3) Phalanges allow hand and foot dexterity.
(4) Opposable thumb (or big toe) allows digit to touch other
fingers.
(5) Primates have a powerful precision grip.
(6) Primates have a distinctive spinal column with five vertebral
types.
iii. Primates Have an Enhanced Sense of Touch
(1) The ends of fingers and toes are sensitive and allow for
maximum information from environment.
iv. Primates Have an Enhanced Sense of Vision
(1) Eyes are rotated to the front of the head with overlapping fields
of vision.
(2) Most primates see in color.
v. Primates Have a Reduced Reliance on Senses of Smell and
Hearing
(1) Most higher primates have lost the naked rhinarium (wet
nose).
(2) Some prosimians retain the rhinarium.
(3) Smell is a secondary sense in most primates.
c. Dietary Plasticity—Primates Eat a Highly Varied Diet, and Their
Teeth Reflect This Adaptive Versatility
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i. Primates Have Retained Primitive Characteristics in Their
Teeth
(1) Dental traits in four functionally distinct tooth types
ii. Primates Have a Reduced Number of Teeth
(1) Dental formula records number of teeth in one jaw
quadrant.
(2) 2/1/2/3 is the formula for Old World monkeys and apes.
(3) 2/1/3/3 is the formula for New World monkeys.
iii. Primates Have Evolved Different Dental Specializations and
Functional Emphases
(1) Premolars and molars used for grinding
(2) Molars have different numbers of cusps.
(a) Bilophodont (two lobes)
(b) Y-5 (cusps in the shape of a “Y”)
(3) Canine-premolar honing complex slices food.
(4) Enamel thickness varies across order.
d. Parental Investment—Primate Parents Provide Prolonged Care for
Fewer, but Smarter, More Socially Complex, and Longer-Lived Offspring
i. Female primates give birth to fewer offspring than other
mammals.
ii. Investment in offspring is high.
iii. Development period is longer, especially in apes.
iv. Development period is related to larger brain size in primates.
v. Humans have the largest brain for body size.
2. What Are the Kinds of Primates?
a. Over two hundred species with great physical and behavioral
diversity
i. Differences have occurred through evolution.
ii. Living primates provide models for understanding evolutionary
past.
b. Ad Hominin? Genetic vs. Anatomical Classification
i. DNA analysis demonstrates that humans, gorillas, chimpanzees,
and bonobos are more closely related than each is to orangutans.
ii. Chimpanzees and humans are more closely related than either is
to gorillas.
iii. DNA analyses (genetic classification) provide a different window to
the relationships between primates from anatomical classification, which provides insight
into adaptations. This book uses anatomical classification.
c. Prosimians: The Lesser Primates
i. Among oldest living primates
ii. Developed sense of smell
iii. Combination of nails and claws with less dexterity than other
primates
iv. Geographic range: Madagascar and Southeast Asia
v. Tarsiers share some traits with prosimians and anthropoids.
d. Anthropoids: The Higher Primates
i. Old World monkeys (catarrhines)
(1) Nostrils separated by a septum that points downward.
(2) Most diverse and most successful nonhuman primates
(3) Tough sitting pads on the rear (ischial callosities)
(4) Inhabit terrestrial and arboreal habitats in Africa and
Asia
(5) Two subfamilies: cercophithecoids and colobines
(6) Baboons, macaques, mandrills, colobus
ii. New World Monkeys (platyrrhines)
(1) Rounded nostrils separated by a septum
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(2) Prehensile tail
(3) Inhabit arboreal habitats in Latin America
(4) One subfamily: ceboids
(5) Spider, squirrel, howler monkeys
iii. Hominoids
(1) Great Apes: orangutan, chimpanzee, bonobo, gorilla
(a) Sagittal crest in gorilla, orangutan
(b) Chimpanzees omnivorous
(c) Humans characterized by skeletal structure for
bipedalism
(2) Lesser Apes: gibbon, siamang
(a) Skilled brachiators
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