Midterm 2 Bio Anthropology 002

The General Characteristics of Primates

- large brains

- forward-facing eyes with overlapping fields of view, depth perception

- grasping hands

- flat nails instead of claws

- generalized body plan

- generalized teeth

- enclosed orbits

- opposable thumbs and toes

- fairly long digits

Dental pattern of old-world higher order primates

2:1:2:3

- 2 incisors

- 1 canine

- 2 premolars

- 3 molars on each side of the upper and lower jaw

The General Characteristics of Primates

- large brains

- forward-facing eyes with overlapping fields of view, depth perception

- grasping hands

- flat nails instead of claws

- generalized body plan

- generalized teeth

- enclosed orbits

- opposable thumbs and toes

- fairly long digits

Dental pattern of old-world higher order primates

2:1:2:3

- 2 incisors

- 1 canine

- 2 premolars

- 3 molars on each side of the upper and lower jaw

Opposable big toes in primates

- a thumb that can touch each of the four fingertips, enabling a grasping ability

- allowing for a greater degree of grasping and dexterity - useful for primates that live in trees, aiding in climbing and grasping branches

- allowing them to grasp branches and navigate their arboreal (tree-dwelling) environment effectively

Where do lemurs live?

- Madagascar

Strepsirrhini (Suborder of primate 1/2)

- damp nose, particles on nose gather info from environmental

- damp nose V

- dog, cats

- lemurs, lorises

- toothcomb > dig and grooming

Haplorhini (Suborder of Primate 2/2)

- dry nose

- mustache between nose and upper lip

- nose pick up particles

- not as specialized for specific of smells

- tarsiers, monkeys, and apes, including humans

Arboreal adaptations

- forward facing eyes, great vision and depth perception

- grasping hands

- opposable thumbs/opposable big toes

- long digits

Prehensile tail

- A tail that acts as a kind of a hand for support in trees; common in New World monkeys

- wrap around stuff grab on stuff and branch, dangle

Bipedal adaptations

- upright posture

- additional curve to spine

- broader hips

- lower limbs longer than upper limbs

Natural selection

- what is selecting for body size, predict single male or multiple females

- how group is organized

Sexual Dimorphism

- observable differences in appearance or behavior between the sexes of the same species

- variations in body size ex: male that are tall and large female are small

- 2 diff forms

- monogamous >

- reduced sexual dimorphism >males were cooperative, not competitive

- larger the male> the more equipped it will be to outcompete other males for sexual access to females

- early hominins were highly dimorphic> competing males were likely not involved in caring for their offspring

- monogamous > there is less competition for females and thus little sexual dimorphism

- monogamous > one male, one female. partner's reproductive success is tied to that of the other, and the male invests a relatively large amount of time and energy in the young (for example, through protection and food acquisition)

Social organization

- different reproductive strategies

- compete access mates

- select for larger body size than females

- infanticide> kill off competitors for offspring

Kin Selection

- Natural selection in favor of altruistic behaviors that increase the fitness (organism's ability to survive and reproduce in a given environment) of the donor's relatives

- benefit to yourself if you help close relatives to survive help genes overall better chance of surviving

- reduce group survival → helping individuals with similar genes to survive, or closer relative

Gibbon social organization

- One male, one female

- consists of an adult male, an adult female, and their immature offspring

- Mating is typically monogamous , so each partner's reproductive success is tied to that of the other, and the male invests a relatively large amount of time and energy in the young (for example, through protection and food acquisition)

What distinguishes monkeys and apes

Monkeys

- limbs same length

- quadruple --> walk on 4 limbs

- long spine

- tail

Apes

- shorter spine

- no tail

- broader shoulders

- dangle between and below branches

Shivering stress response

- Vasoconstriction and shivering; effects reduce after continual exposure brings warmer skin temperature

- the human body's first response to cold stress is vasoconstriction, the constriction of the blood vessels beneath the skin

- decreasing the diameter of the blood vessels reduces blood flow and heat loss from the body's core to the skin

- the chief mechanism for producing heat is shivering

Limb and body proportions in cold-adapted populations

- higher metabolic rate

- stock ear and limbs

- bulk body help survive

Developmental adaptations (children living at high altitude lungs)

- children living at high altitudes develop adaptations in their lungs and cardiovascular system to thrive in lower oxygen conditions

- adaptations: lung volume, increased ventilation, and enhanced pulmonary diffusion, allowing for better oxygen uptake

Acclimatization

- (ALL REVERSIBLE) short term adjustments

- thermal regulation

- maintaining body temp sun- warm = in order to survive stressor, sweat, produce moisture and cool off skin and make it cold- when cold cold= rely on vassal constrictions narrowing of blood vessels near the skin's surface, which reduces heat loss and helps maintain body temperature in colder environment, prioritizing internal organs

Stages of development

- infants

- toddlers

- juveniles

- adults

- senescence