From Review Session Flashcards
(86 cards)
List four features that define primates
- Forward facing eye sockets
- Post orbital bar
- Petrosal bulla
- Fingernails and toenails instead of claws
(Other) shortened snout with at least 3 types of teeth, collarbone, radius and ulna and tibia and fibula, grasping hands and feet with mobile thumbs, vertical posture, longer lives and stages of life, enlarged brains, increased areas of seeing and decreased in smelling
What is the intermembral index? How is it calculated? What does it indicate? (Note three parts)
The intermembral index is the relative limb length quantified in a ratio
It is calculated by humerus length + radius length/ femur length + tibia length
It indicates arm to leg ratio which indicates if the species is a leaper as leapers have low intermembral index meaning they have longer legs
What are primates
Linnaeus created order primates
Grouped together based on similar features
What does information on this 160 million year old fossil tell us about
1. The earliest Eutherian mammal
2. The general morphology of primates today
We have retained many features of early Eutherian mammal as primates
List number of cranial (skull) features that define primates
Olfaction (reduce smell increase vision reliance with forward facing eyes), post orbital bar, Petrosal bulla
List number of postcranial (limbs) features that define primates
Grasping hands and feet, clavicle, nails instead of claws, forearm (radius and ulna) and leg (tibia and fibula)
Primates are (great majority)
Tropical arboreal mammals
Primate adaptations
Layers of rain forest
Utilize and adapt to different layers of rainforest so less competition with others
Reproductive strategies
Members of the sex that invest less in terms of reproduction compete for the sex that invests more
Males go after females
Because males compete for females the distribution of males and the types of social groups that primates form are
Constrained by the density and distribution of females
More male reproductive strategies
Males fight each other physically
Not always brute strength and still climb hierarchy
Infanticide way to compete with each other
Sperm competition (access to egg over mate, chimps, bigger deposit winner)
Why do primates live in groups
Group living has costs and benefits
What are the costs and benefits of primates living in groups
Benefits: mates resources protection
Costs: competition travel for food
What determines how females distribute themselves across the landscape/what are females (generally) most concerned with finding
Food for gestation and lactation
What determines males distribute across landscape/ what are males most concerned with finding
Female
Some species where male and female are
Monogamous
Other species
Multi male/female groups up to 600 individuals
Social Organization
Dispersed polygyny (noyau), polygny (one male multi female), monogamy, polyandry, multi male group, one male group, fission-fusion,
Heterodonty
Possessing multiple tooth types
Dental Formula
1. What is it
2. How determined
3. Human dental formula
4. What dental formula says about diet
- Number of each tooth type in each of the four quadrants
- Quadrants in mouth (#incisors, #canine, #premolars, #molars)
- 2.1.2.3
- Not much but features of teeth help with diet
Dietary Categories
Frugivores-fruit
Folivores-leaves
Insectivores-insects
Gumivores-exudate/sap
Granivores-seeds
Carnivores-meat
Omnivores-multiple (in general)
Kay’s Threshold
Over 500 grams of body size not really insectivorous
Not able to sustain energy costs on just eating insects cause too small and harder to catch them if large primates
Relationship of teeth and food material properties
Size and shape of incisors and cusps on molars
Tall incisor size frugivores
Shearing cusps on molars folivorous
Knuckle walking
Large, long fingers need to be that way for trees but on ground (terrestrial quadrapedialism) need them tucked away so walk on knuckles cause had to lift hands before knuckle walking