Biological Anthropology Exam 2

Carolus Linnaeus

developed binomial nomenclature

In binomial nomenclature the first word is

Genus and capitalized

In binomial nomenclature the second word is

Specific epithet and lower case

Taxonomy predates evolutionary biology

True

Phylogenetic Systematics

classification of organisms by their order of branching on an evolutionary tree

phylogenetic systematics is represented by

Cladograms

phylogenetic species concept

an irreducible grouping of organizations distinct from other groupings where there is a parental pattern of ancestry and descent.

monophyletic grouping

Any grouping that contains the node (common ancestor) and all groups that descend from it.

paraphyletic grouping

a grouping that consists of an ancestral species and some, but not all, of the descendants

polytomy

More than 2 branches off one node

Primates are broken into

Strepsirhines and haplorhines

Strepshirines are broken into

Lemurs and lorises

Haplorines are broken into

Tarsiers, new world monkeys, old world monkeys and apes

Features of hands and feet

Grasping hands and feet
Opposable big toe
Fingernails
Sensitive fingertips

Features of sensory organs

Acute vision
Poor olfaction
Forward eyes
Binocular vision (better depth perception)
Stereoscopic Vision

Large complex brain

All mammals have a neocortex (extra layer t the brain)
Wrinkles and folds increase surface area to allow for more tissue.

Post-orbital bar/closure

Bar that provides protection to the eye.
Without it the eyes jiggle when chewing.

Primates are very social and have complex social structures

80% of primates live in groups

Long life histories

Long pregnancy
Small litters
Body size (larger)
Long juvenile period (gives time to grow)
Long mother-infant bond
Long life span (live long in comparison to our body size)

Auditory Bulla

One derived trait of primates
Temporal bone forms part of it
Only seen in early development

Strepsirhines

more primitive (similar to ancestral form)
Nocturnal adaptations
Greater reliance on scent
Slightly longer snouts
Forward eyes

Tapetum lucidum

Nocturnal adaptations.
Reflective lens/coating of the eye. Reflects light back out.

Rhinarium

Greater reliance on scent.
Wet, hairless nose.
Wet nose helps collect molecules

Hairless nosed primate characteristics

Philtrum (upper lip) is tied to the maxilla
hairless nose
wet noes
Like dogs

Furry nosed primate characteristics

Philtrum not attached to the maxilla
Hair on and around nose
Like humans

Strepsorhines Post Orbital Bar/Closure

Thin bar present.
Can see eye from the back
Eye kinda steady

Haplorhines Post Orbital Bar/Closure

Full closure.
Cannot see eye from the back
Keeps eyes steady
Muscles not attached to the eye

Strepsirhines Characteristics

Unfused frontal bones.
Grooming claw (only one long, curved, and pointy nail).
Tooth comb (Elongated bottom incisors and canines used to groom or to scrape trees)

Lemurs and Lorises

Share primitive strepsirhine characteristics

Haplorhines

More derived (different), advanced characteristics.
Diurnal adaptations to the eye.
No reflective portion to the eye.
Greater reliance on vision and depth perception.
Reduced snout (lower reliance on scent)
Eyes facing forward and close
Larger bodied
Larger social groups

Retinal Fovea

Pit in the back of the eye that is very sensitive. Helps us to focus light and give us precise, clear, vision in daylight.
Doesn't see well in the dark

Tarsiers

Fused frontal
No full eye socket
Postorbital plate (shallow plate for wide eyes to sit)
Unfused mandibular symphysis
Vertical posture
Large hands and feet
Long tarsal (heel) bones

New World Monkeys

3 premolars
Zygomatic/parietal contact
Ear ring

Old World Monkeys and Apes

2 Premolars
Frontal/sphenoid contact
Boney ear tube

Old World Monkeys

Smaller brain
Narrow nose
Narrow palate (cinch in closer at the back of the mouth
Bilophodont molars (4 cusped with 2 rows of cusps)
Long trunk
Cannot adduct arm as much due to shoulder placement
Tail

Apes

Larger brain
Broader, wider nose
Broader, wider palate
No tail
Shoulder modification to be able to hand and swing
Y-5 Molars (5 cusped with broader asymetrical molars)
Short trunk
Longer arms so they can take longer swings
Shoulder blade dorsal to allow greater rotation

Inclusive Fitness

Your reproductive success and the reproductive success of those you share your genes with

Reproductive Success

The number of offspring that you go on to produce

Colobines

An old world monkey
Leaf eater
Sharp cusps
Reproductive success is not as greatly linked to defending resources

Cercopithecines

An old world monkey
Eats fruits
Lower, rounded cusps
Figure out when fruit seasons are and where those fruits are
Female philopatry
There's a need to defend territories in order to protect their resources (food)

female philopatry

As an adult, the females stay in the social groups in which they were born in.

Ape characteristics

Smaller social groups than monkeys
Will be bipedal if needed

Ape systematics is broken into

Lesser apes and greater apes

Lesser apes are

Gibbons and siamangs

Greater apes are broken into

African apes and orangutans

African apes are broken into

Gorillas and humans and chimpanzees

Chimpanzees are broken into

Bonobos and common chimps

Gibbons

Hylobates Iar

Siamangs

Symphalangus Syndactylus

Orangutans

Pongo Pygmaeus

Chimpanzee

Pan Troglydytes

Bonobos

Pan Paniscus

Indications of social structure

Diet and predator risk (what/when they eat, teeth)
Body size (fossil size vs current)
Sexual dimorphism (male and female sizes)

Why live in groups

Predator Protection, protection from infanticide
Most primates live in 2-300 individuals

Benefits to group living

Avoidance of predators
Improved foraging efficiency
Protection against coercion/infanticide
Protect resources
Safety in larger groups

Costs to group living

Attraction of predators
Increased feeding competition
Social conflict
Health/disease/parasites

Solitary/Noyau

1 male, 1 female, and offspring
Polygynous
Males defend their territory (territory may overlap multiple females)
Males have high reproductive success
Females have lower reproductive success as they have dependent children

Sneaker males

Males who do not have fat pads as they are not territory holding males. They sneak through into male territory for food and women. Force themselves on women. If caught, act like a female

Monogamy

1 male, 1 female, offspring
Rare
Monogamous
Used because of infanticide
Males stay to protect children and female
Male and female have equal reproductive success

Polyandry

Multiple males, 1 female, offspring, non-breeding adults
Even rarer
Monogynous and polyandrous
Males all mate with one female
Female can mate with multiple males
Males care for children
Reproductive success is unequal between the sexes and the males themselves
Males and females are roughly the same size

Alloparenting

Females will stick around with heir families and take on the male caretaker role until they are able to find males of their own.

Scramble competition

Dispersed, low value resources that are distributed evenly.
Scramble to get enough food, no direct competition. If one patch is eaten, just move to another.
Low aggression

contest competition

Clumped, valuable high quality, rare, resources.
Worth fighting over.
More then what one animal needs
Work together to protect resources
Females create bonds

Fruits

High quality, clumped resources.
Rare resource worth defending

Leaves

Low quality, dispersed resources

Frugivores

Long day ranges
Large home ranges
Groups of related females with strong social bonds
Form territories
Exclude others

Folivores

Shorter day ranges
Smaller home ranges
Groups of females with loose social bonds
Food is abundant

Wranghams rule

Females live in groups when it maximizes their reproductive success.
Males look to benefit their reproductive success by finding a group of females and defending it from other males

Polygyny

1 male, multiple females, offspring
Males mate with multiple females
Females mate only with the lead male
Gorillas
Males are very stressed - low immune systems
Only possible if females are defendable
Sexual dimorphism is high
Variance in reproductive success is high

Bruce Effect

If a new male comes into the group, females will spontaneously abort the child they are carrying. Minimizes energy loss

Polygamy (cohesive groups)

Multiple males, multiple females, offspring
Groups of females are too big for one male
Females are normally somewhat related
Males are not normally related
All groups but apes

Polygamy (Fission-Fusion)

Multiple males, multiple females, offspring
Apres, chimps
Males patrol outskirts of territory
Communities come together and then separate.
Males travel together, females travel with children
Males hunt together
Males tend to be closely related
1 male cannot monitor all the females
Variance in males reproductive success

Male-Male Mate Competition

Direct- Fighting
Indirect- Sperm competition
Alkalinity of semen, penile spines, plugs, quantity of sperm

Polygyny teeth

Males have large, sharp canines
Females have smaller, not sharp canines

Monogamy teeth

Males and females have larger, sharper canines

Male-male competition in monogamous and polyandrous

No dimorphism
Rather small testes

Male-male competition in solitary

Weak dimorphism
Large testes

Male-male competition in polygamous

Some dimorphism
large testes

Male-male competition in polygynous

Strong dimorphism
Small testes

Indications of diet

Dental morphology (shape)
Anatomy of digestive tract (length, shape, complexity)
Body size

Insect eaters

Very small body size (Less than 1 pound)
Sharp cusps (to pierce into exoskeletons)
Short, simple gut
Tarsier, pigmy marmoset

Fruit eaters (frugivore)

Medium body size
Broad incisors
Low, rounded molar cusps (crush/grind)
Long, small intestine (fruit is easy to digest but needs time to extract nutrients)
Gibbon, chimp

Leaf Eaters (folivore)

Medium to large body size
Small incisors
high, pointed molar cusps (chop into smaller pieces)
Multi-chambered stomach or enlarged caecum (pouch), or enlarged colon
Complex intestine to slow down digestive process since leaves are more fibrous
Western lowland gorilla

Gum Eaters (gummivore)

Small body size
Stout incisors (scar trees to get out sap)
Enlarged caecum (puch)
Takes over 17 hours to digest
Low intensity food option
lemurs

Indications of locomotion

Anatomy of limbs (shape, length, proportions)
Orientation of the head attacking on the trunk
Shape of thorax and pelvis
Bigger = more important

Expected Adaptations for Locomotion

Relative length of limbs = intermembral index

Formula for locomotion

humerus + Radius
-------------------- X 100
Femur + Tibia

Quadrupedal leaping

All limbs involved
Legs push off
Arms reach to grab
Long lumbar region
Many species

Vertical clinging and leaping

Start vertical
Legs push off
Spin in mid air
Short lumbar region
Lemurs and tarsiers

Leaping

IMI small

Quadrupedalism: Arboreal

Most common locomotor pattern
IMI: 70-110
limbs similar in length
Short limbs
Flexed gait (bent)
Long tail (help with balance)
lateral, triangular, scapula
Narrow thorax (allows arms to come to front)
Grasping foot (to hold onto branches)
Deep ulna
Long olecranon process

Quadrupedalism: Terrestrial

Rare: some African monkeys
IMI 70-110
Limbs similar length
Lateral scapula
Narrow rib cage
Long limbs
Shorter tail, fingers, and toes
Restricted shoulder joint
Dorsal foramen magnum
Posteriorly olecranon process
Narrow thorax

Brachiation/Suspension

Gibbons and apes
IMI: large, over 120
Long forelimbs
Short hindlimbs
Rounded joints for a large range of movement
Long, curved fingers
Short lumbar region
Dorsal scapula
Broad thorax
No tail
Mobile hip joint
Short olecranon process

Knuckle-walker

Chimps and gorillas
IMI: about 110
Long forelimbs
Retained suspension traits in shoulders
Forelimb supported on dorsal surface on digits

Bipedalism

Walking on 2 feet
IMI: small about 70
Long hind limbs
S curved spine
Short, curved pelvis
Valgus knee (angles inward)
Not grasping foot
Short toes
Hallux adducted (push off with big toe)
Short, thick heel
Short ischium
Short, broad ilium
Large femur head
Central foramen magnum

Benefits of group life

Avoidance of predators
Improved foraging efficiency
Protection against coercion/infanticide

Costs of group life

Attraction of predators
increased feeding competition

Goal of group life

Maximize reproductive success

Diurnal primates

Group living

Nocturnal primates

Solitary