ANTH 3000 FINAL

Attractivity

Traits/behaviors that increase an individual's sexual attraction
ex: Sexual Swellings

Proceptivity

Behavior that indicates an individual is sexually interested in another individual ex: female capuchins throwing stones at males to attract them

strepsirhine sexual patterning

Go through estrus (A basic mammalian pattern that involves discrete periods during which a female mammal is willing, motivated and physically able to mate with a male)
-Breeding seasonality for some strepsirrhines.
-Estrus period is strictly confined
-Strong hormonal facilitation- but there is still evidence for female choice in some species (think of female lemur whacking an undesired male on the head)

haplorhine sexual patterning

-Menstruation
-Female sexuality is under less hormonal control
-Over 50% of primate species are sexually active outside of fertile period
-No estrus

male sexual patterning

No regular cycles of sexual behavior unless females also show seasonal fertility patterns.
Female sexuality appears to drive male sexuality

male sexual displays

Shows power and that the male is healthy (Ex:Mandrills have high levels of testosterone with tons of color)
More examples: Proboscis monkey's nose, male orangutans flat "flange" face, red and blue male genitals of verbate monkeys

function of female sexual swellings

Found primarily within multi-male and multi-female social groups to possibly increase mate competition among males
Increase chances of conception by advertising reproductive status
to avoid infanticide

what type of group would have sexual swellings?

Multi male, multi female social groups, in order to increase mate competition among males.

Are larger swellings related to reproductive success?

yes, Size matters because bigger sexual swellings signals larger number of offspring produced

Do females exhibit behavioral sexual cues? What are some examples?

Stone throwing as sexual display by female capuchin monkeys
Eye contact in gorillas

Female strategy

to gain and maintain adequate access to food and other important resources for reproduction
Ideal for F: exclude all males (reducing feeding competition); seek out males only when female is fertile.
Share resources with other related females depending on the environment.

Direct Female Choice

choosing a mate or refusing to mate with a particular male

indirect female choice

choosing males in one male groups e.g. Geladas

Basis for female choice

To avoid inbreeding
Frequencies of incestuous matings between brothers/sisters in common chimpanzees
To mate with males with superior traits (ex: using high rank as a measure of "good genes")

Sexual Strategy of female japanese macaques

Females have multiple male partners when they are available
Females show a preference for mating with sexually unfamiliar males for more genetic diversity

Mate Preference of Wild Muriqui Monkeys

Females who recently immigrated into the group preferred young males over older males but showed no such pattern for female who had been in the group for some time
Mean number of sexual partners: females = 8, males = 14.1

Male Primate Limitations

The number of reproductive females and male competitors
Male strategy: to find mating partners while reducing male competition for mates
Ideal system for males: exclude other males; be the only reproductive male in a one-male group

Male Patterns in multi-male groups

Stay- doesn't work very well cause the females don't find you attractive
Transfer to another group
Go to an all male group
Lone male- predation high
Join only for mating season then leave (Ringtailed lemurs)
Remain at periphery and mate when can

Types of mating competition for males

Direct competition, Disrupting other male's mating attempt, and Develop special bond with females(gelada baboons)

Males expressing mate choice

Distribute matings to ensure fertilization. They can do this by:
Mating with females most likely to conceive and be good mothers or mate with F who prefer them

Infanticide

One male group: Killing the offspring of other males results in females becoming fertile and widens the window of opportunity for new males, potentially leading to more offspring for them.
Most known by M, but also occurs among F- where it is an extreme form of reproductive competition.

What do males look for in females?

Fat distribution, sexual swellings(Size matters because bigger sexual swellings signals larger number of offspring produced)

What role does body size play in explaining life history patterns in mammals. What role does phylogeny play?

-Role of body size: larger animal= older age at first reproduction, larger animals have a longer lifespan and a lower BMR, larger animals have lower predator pressure. Essentially the smaller the body size the more accelerated the life history will be
-Compared to other mammals of similar size, primates' life histories are slower. They go through puberty later and live longer.

How do primates compare to other mammals of similar size in terms of life history? What is an example that demonstrates this difference?

Primates have slower life history than other mammals of similar size.
An example is the galago compared to the norwegian rat.
Same body size in the control
Lifespan: G=16 years R=2 years
Age at puberty: G=9-12months R=36-67 days
Gestation: G=121-125 days R=21 days
Litter size: G=2 R=12

How do humans differ from other primates in terms of life history patterns?

Only primate with adolescence and menopause, and slowest life history of all primates

Is menopause a universal pattern among all mammalian females and if not why might this be the case?

No(3 total). Good grandmother hypothesis says that menopause may have been favored by natural selection because postmenopausal women are better able to care for their existing children or daughters offspring

How do the birthing patterns differ between humans and non-human primates?

Nonhuman primates face towards mother and assist with birth while humans are born facing away from mother and use birthing assistants.

R Selection

females produce numerous offspring, but invests little in each offspring

K selection

females produce fewer offspring, but invests more in each

How does a possum differ from a zebra in terms of maternal care?

Opossum: produce many underdeveloped youth who live in the mother's pouch and grow quickly,
mothers thus have a high cost for a short time early on but lower costs in pregnancy
Zebra produces one, well developed young. so costs here are high in pregnancy

K selected primate traits

PRODUCE FEWER YOUNG AT A TIME
CARRY THEIR INFANTS WHEREVER THEY GO
DEGREE OF DEVELOPMENT AT BIRTH
(PRECOCIAL: infants born with their eyes open and with high level of independent activity from birth. most primates are precocial at birth (zebra)) <is this right?
HIGH COST FOR RAISING YOUNG

Does learning play an important role in primates learning to be good mothers?

Yes, motherhood is not instinctual... ex- Orangutans

How does ecology affect a primate mother's reproductive success? Does body fat play a role in this?

Speeds up life history
baboons who lived near a tourists lodge and regularly foraged on leftovers
1. conceived their first offspring earlier
2. infants grew faster and weaned earlier
3. females had shorter inter-birth intervals

How do human infants differ from non-human primate infants?

Human infants are secondarily altricial while nonhuman primates are precocial, nonhuman primates may assist in birth. Nonhuman primates brains are 60% developed at birth while human infants are born with 30% brain development. Most brain development happens after birth in humans

Why do human infants have so much body fat when they are born?

to fuel their costly brains

How does infant brain development differ between humans and non-human primates? How is this relevant to the issue of maternal care and costs

Nonhuman primates brain develops mostly in the womb while human infant's brain develop mostly after birth. Humans have to invest more energy into infant care

Is male care common among mammals? In what situation would we see male care?

Not common, there is male care in 5% of mammals. Male cotton top tamarins are monogamous primates and males are highly responsive to infant stimuli and are known to be carrying infants. Three weeks before birth, prolactin rises 20% and for three weeks after testosterone drops 33%. Cortisol goes down.

Why is cooperative breeding important? How is this related to the juvenile period in humans?

Helps lower cost for mothers because human infants are very difficult to raise. Results in reduction in juvenile mortality rates

How are human females able to produce more offspring that chimpanzee females over the same amount of time?

Human mothers can focus on more children at one time. Chimps have to focus on infants till they are done nursing and are independent. A big reason for humans being able to care for more than one is cooperative breeding

Reptilian Brain

the 4 f's(fighting, fleeing, feeding, reproduction ;))

Triune Brain

Reptilian, Paleomammalian, Neomammalian

Paleomammalian Brain

emotions

Neomammalian Brain

abstract thought, deeper understanding of things

Why is brain size alone not enough to explain primate brains?

Encephalization quotient. Brain size alone doesn't determine intelligence, it is more about brain to body ratio. Sperm whale has largest absolute brain but humans have highest encephalization quotient

Encephalization Quotient

brain to body ratio

What is the "ecological" hypothesis for big primate brains?

no nonhuman primate stores food--they must find it
food must be found efficiently, primates don't move randomly,
use most direct food path, even if not visible

Is extractive foraging unique to primates? Does this foraging technique explain primate intelligence?

why stay in one area versus the other? If you can count you can determine where to focus your energy
- when you can't see the food item but have the ability to think where the food could be
when food source is not immediately evident
- Doesn’t completely explain; social aspect

What is the "social" hypothesis for big primate brains?

the more social a primate is the larger the brain is
neocortex size relates with sociality, can help navigate social surroundings more effectively
large groups-many interactions, you need to keep track of positive and negative interactions
kin v. non-kin, alliances v enemies, individuals as social tools, pairbonding (close relationships like mother and child)

Does brain size matter?

In relation to body size it sure does
Each section of the brain matters (for example a larger neocortex matters) and the amount of cortical folding matters (neuron density)

What is Machiavellian intelligence

the capacity of an entity to be in a successful engagement with social groups.
manipulating others for own personal gain,
make and break alliances or groom to meet one's own needs