Chapter 1 Notes

Question 1

The very first primates probably coexisted with the dinosaurs during the

Answer 1

Mesozoic era

Question 2

Fossil record shows primates proliferated during the

Answer 2

Cenozoic era (65 mya)

Question 3

The first primates to evolve are what and did they resemble today’s primates?

Answer 3

Basal primates
They did not resemble todays primates

Question 4

Why did basal primates not resemble todays primates

Answer 4

1. Not yet been adapted to living in trees (arboreal) but instead were ground living and terrestrial
2. Probably resemble hedgehogs more
3. Probably had relatively large eyes that faced more to the sides
4. Timid creatures that moved in a scurrying nervous manner
5. Keen sense of smell and taste for insects
6. They were nocturnal (based on characteristics)

Question 5

What event killed the dinosaurs and 75% of all species of life?

Answer 5

The K-T extinction event

Question 6

What important trait probably helped basal primates survive the K-T event?

Answer 6

As nocturnal animals, they were already adapted to the dark
The world was in a sheet of dark dust
After the event resources became available for supporting new species

Question 7

Adaptive Radiation

Answer 7

Biologists have long wondered about the exact processes that result in a proliferation of new species over time

Question 8

Most researchers agree that the … is extremely useful for understanding the mechanisms that are responsible for the appearance of new species

Answer 8

Theory of natural selection
Species give birth to more offspring that can be supported by available resources where certain individuals with more favorable characteristics are more likely to take advantage of the limited resources to successfully reproduce relatively large #’s of offspring
Frequently genetically based and may be inherited
Certain features naturally selected in future pops and some weeded out

Question 9

Unnatural selection

Answer 9

Animal breeders practice it when they breed stock for certain characteristics

Question 10

Distant biological species

Answer 10

Forces of natural selection continue long enough and separated by geographical boundaries, once-similar populations are likely to differ enough that matings between them would no longer produce viable offspring

Question 11

Biological species concept

Answer 11

Believe that interbreeding cannot occur between members of the two species,

Question 12

Some primatologist prefer a less-rigid … that recognizes the role of natural selection in shaping new species in different environments, but without strict requirement that interbreeding between the two species be physically impossible

Answer 12

Ecological species concept

Question 13

What is the most important source of information when it comes to dating primates?

Answer 13

The primate fossil record

Question 14

Because of limitations in the fossil record

Answer 14

Paleontologists frequently resort to educated guesswork when formulating their interpretations

Question 15

Fossil record tricky to interpret for a number of reasons

Answer 15

1. Good deal of luck for an animal to become a fossil, must die under circumstances to allow it to become deposited in the kinds of sediments that foster a process in which organic substances are replaced by minerals, why mostly teeth and small fragments of bone

Question 16

What’s useful to identify species of fossil?

Answer 16

Skull and teeth

Question 17

Postcranium and fossils

Answer 17

One really needs to observe the postcranium to assess details of body size and limb proportions that are related to how primates moved

Question 18

Paleocene Primates

Answer 18

65-55 mya

Question 19

Because of … the geography of the world during the Paleocene epoch appeared much different from the geography today

Answer 19

Continental drift
Distribution of primates changed with drifting continents

Question 20

Example of paleontologists needing to revise their overall view of primate evolution

Answer 20

In early 1990s in the case of Paleocene fossils from North America and Europe known as PLEASIADAPIFORMS which were traditionally thought to represent the oldest known primates

Question 21

Plesiadapiforms

Answer 21

Lacks typical primate features like post orbital bar and forward facing eyes but has some like auditory bulla
Represented first by mostly jaws, teeth, and smashed skulls until 1990 in Wyoming discovery of first intact skill and some unstudied fingers
Had a number of non primate features

Question 22

Eocene Primates

Answer 22

55-36 mya

Question 23

Fossil primates have been found in Eocene deposits in

Answer 23

North America, Europe, Africa, and China

Question 24

Fossil evidence regarding the forms of the teeth and the sizes of the body and eyes indicate that … were tiny nocturnal primates that are insects and fruit

Answer 24

Omomyoids

Question 25

Example of a living fossil or structural ancestor

Answer 25

Tarsiers that look like modern forms inhabited Chinese forests 45 mya then Tarsius is the dramatic example

Question 26

Omomyoids also known as

Answer 26

First Wave Primates

Question 27

Adapids

Answer 27

Also abundant in N America and Europe Larger than omomyoids Preferred eating fruits and leaves May have been diurnal although fossil evidence regarding relative size of eyes is difficult to interpret Some believe they gave rise to lemurs and lorises Second Wave Primates

Question 28

Who evolved by Eocene times

Answer 28

Ancestors of first monkeys, simians or early anthropoids

Question 29

The arboreal theory

Answer 29

The primate pattern resulted from natural selection for features that permitted early primates to live in trees

Question 30

Attributes of arboreal theory

Answer 30

Collarbones, finger/toenails, two bones in forearm, grasping hands and feet permit stability of the shoulder, increased mobility of the arm, and good grasping and manipulative ability of the hands and feet

Question 31

Feature of eyes moving from side to front facilitates three dimensional depth perception or

Answer 31

Stereoscopic vision

Question 32

Visual predation hypothesis (bug-snatching theory)

Answer 32

Cartmill suggests that grasping and visual abilities of earliest primates were selected in conjunction with seeing and catching insects

Question 33

Expansive Tissue hypothesis

Answer 33

Because the brain and guts consume much more of the body’s energy than do many other tissue so it suggests that a trade-off occurred in which the development of enlarged brains was based on a commensurate reduction in gut size that required a shift to a higher quality diet

Question 34

Oligocene Primates

Answer 34

36-24 mya

Question 35

What contributed to the extinction of local populations of prosimians

Answer 35

Cooler drier climates in Europe and N America

Question 36

Oligocene is the appearance of the earliest known

Answer 36

Monkeys in S America

Question 37

Fayum Depression site in Cairo Egypt

Answer 37

Site of a lot of Oligocene primate fossils 60s revealed diversity of arboreal quadrupedal primates with varying amounts of leaping abilities

Question 38

Best known Fayum primate was

Answer 38

Aegyptopothecus zeuxis Largest Fayum primate 8kg Short limbed, heavily muscled, diurnal primates, same number and general kinds of teeth as modern Old World monkeys and apes, teeth are primitive, hard to classify if monkey or ape Some say more Hominoids (closer to Miocene apes, living apes, and humans) and some say more catarrhines (OW primates)

Question 39

Miocene Primates

Answer 39

24-5 mya

Question 40

Variety of apes had evolved in

Answer 40

Tropical forests and woodlands of Eastern Africa

Question 41

Had many postcranial features common with

Answer 41

Quadrupedal monkeys

Question 42

Miocene Primates had more … teeth

Answer 42

Furgivorous Climate cooler and drier, tropical forests replaced by woodlands Molars became larger with thicker enamel for chewing hard gritty plant food (more folivorous)

Question 43

Example of Miocene primate

Answer 43

Proconsul When found, enough range of individuals to chart its growth Ape like big toe and lack of tail Monkey like wrists and limb proportions Cautious slow moving arboreal quadruped Relatively large brain and frontal sinus (found in African apes and humans)

Question 44

Plio-Pleistocene Primates

Answer 44

5 mya to 10,000 years ago

Question 45

Pliocene and Pleistocene or Ice Age

Answer 45

Plio: 5-1.8 mya Ice Age: 1.8mya to 10,000 years ago

Question 46

PP Primates beginning global temps

Answer 46

Falling as increasing amounts of water became locked up in ice sheets

Question 47

Drier climate caused equatorial forests to

Answer 47

Shrink causing savannahs

Question 48

PP has no ape fossil record but does have

Answer 48

OWM and NWM in fossil record

Question 49

In PP the first

Answer 49

Hominids (future humans) emerged

Question 50

Individual specimens are dated

Answer 50

By various scientific techniques that estimate the ages of sediments around it or other contemporary species Often difficult to infer precise dates when species originated