Lecture 10

Question 1

changing climates during the latter part of the Cretaceous Period allowed for angiosperms to proliferate, creating an ecological niche for future what

Answer 1

proto-primates, which included:
Purgatorious (genus) and
Plesiadaptaformes (order)

Question 2

True primates appear during the Eocene epoch when

Answer 2

between 54 and 34 mya

Question 3

what prosimians appear first

Answer 3

Omomyids and Adapids

Question 4

Omomyids and Adapids most resemble what

Answer 4

most resemble today’s Strepsirrhines;

Question 5

during the _____ the first true monkeys, such as Aegyptopithecus zeuxis appear at sites like Fayum in present-‐day Egypt

Answer 5

Oligocene, around 30 mya

Question 6

The earliest apes appear during the _______

Answer 6

Miocene, beginning around 25 mya

Question 7

We saw three specific genera of these apes (Miocene) what were they

Answer 7

Proconsul, Kenyapithecus and Dryopithecus

Question 8

This last genus largely represented what

Answer 8

the end of apes outside of Africa and extreme SE Asia. Sometime between 7 mya and today, these various species of disappeared from Africa and Eurasia, and so-‐farun discovered genera developed into gorillas and chimps/bonobos

Question 9

define Anthropoid

Answer 9

informal term akin to prosimian, basically all Haplorrhines minus tarsiers (who are informally prosimians, but taxonomically Haplorrhines)

Question 10

what are Hominoid (superfamily):

Answer 10

All lesser & great apes + humans (so exclude old world monkeys)

Question 11

what are Hominid (family):

Answer 11

All great apes + humans (so exclude lesser apes i.e. gibbons & siamangs)

Question 12

what are Hominin:

Answer 12

all species related to humans since the split from Chimpanzees. Basically, the remainder of this course!

Question 13

can we Compare superfamily Hominoid to Cercopithecoid

Answer 13

Compare superfamily Hominoid to Cercopithecoid (superfamily taxonomic term for Old World Monkeys)

Question 14

what can the term Hominid be compared to

Answer 14

Compare term Hominid to Hylobatid (superfamily taxonomic term for lesser apes)

Question 15

Many animals are ______ bipeds; a far smaller number are _______ bipeds

Answer 15

Many animals are facultative bipeds; a far smaller number are obligate bipeds

Question 16

Humans are the only mammals to move bipedally via ______________

Answer 16

alternating gait

Question 17

what is an alternating gait

Answer 17

one leg, then another; walking)

Question 18

How and why was bipedal locomotion selected for in our hominin ancestors?

Answer 18

The main requirement for obligatory bipedalism is that the body’s center of gravity must be lower (pelvic region compared to the quadrupeds… where they have it in their torso) than that of quadrupeds

Question 19

A number of factors contribute to our lower centers of gravity:

Answer 19

bipeds have long, heavy legs

biped femurs are angled to position our knees almost directly below our pelvises

Question 20

The main requirement for obligatory bipedalism is that the body’s center of gravity must be lower than that of quadrupeds. A number of factors contribute to our lower centers of gravity:

Answer 20

bipeds have long, heavy legs
biped femurs are angled to position our knees almost directly below our pelvises
bipeds have an ‘s-shaped’ lumbar curvature to the spinal column.
Bipeds have a pelvic region (os coxae) more ‘bowl-shaped’ to support weight and the attachment of heavier leg musculature 

The gluteus medius and gluteus minimus connect each ilium to the outside edge of the corresponding femur. These muscles help to compensate for lesser stability we experienced every time we take a foot off the ground.
Apes have these muscles, but they have not developed to maintain balance as ours have.

Question 21

The question of why bipedalism developed is hotly contested; there are a number of competing theories:

Answer 21

1. Tool/weapon use; carrying provisions and offspring
2. Energy efficiency / cooling
3. Environmental changes
   Open grasslands during Miocene Acquisition of food resources from
4. high places
5. Sexual selection
   Social displays
   males were more attractive to females when standing up (very male-dominated view)
6. Male provisioning, female reproductive strategy
   re-hear what he said in lecture recording