Final Exam Study Guide Chapter 9

Question 1

Continental drift

Answer 1

Movement over the surface of the globe of the immense plates of relatively light materials that make up the continents
Earth has changed over time

Question 2

Climate change

Answer 2

Cooling and drying trend over the last 20 million years

Question 3

Changing environment leads to

Answer 3

Adaptations

Question 4

Changing environments led to

Answer 4

Selection pressures

Question 5

How do scientists reconstruct ancient climates

Answer 5

-Reconstructing global temperature

Global climate change:
Cooling trend overall in last 65 million years
Warmer in early Eocene and early Miocene
Cooler and more variable in Pleistocene

Deep sea cores:
Oxygen isotopes
Different atomic mass (16 vs18)
O16 lighter - evaporates into snow and rain
- gets trapped in glaciers and poles during cold times
-high 18O/16O ratio during cold periods.

Question 6

How do scientists know how old fossils are.

Answer 6

-fossilization
Most of what we know about organisms comes from fossils

Fossils- mineralized bones and teeth

Can reconstruct anatomical structure to answer questions
Environment has to be in right condition ( lakeshore or cave)
Needs to be buri es relatively quickly ( avoid scavenger)

Fossils are scarce

Question 7

Carbon dating techniques

Answer 7

Isotopes
Same element but different number of neutrons
Can be radioactive 
Decay at a constant rate
Half life
Half life of carbon-14 is 5,730 years

Question 8

Dating techniques: Clock in a Rock

Answer 8

Use other radio metric methods, carbon decays too rapidly
The decay of potassium to stable argon dating
- half life is 1.25 billion years
- volcanic rocks
- fossils not directly dated, dated to geological feature
- can date fossils millions of years old
- more recent technique :Ar-Ar dating
# more refined , can be done with single rock crystals

Question 9

Uranium lead dating

Answer 9

Flowstones of caves

Question 10

Other dating methods

Answer 10

Thermoluminescence
Electron- spin resonance
Paleomagnetic dating

Question 11

Electron- spin resonance

Answer 11

Technique used to date fossil teeth by measuring the density of electrons trapped in apatite crystals in teeth

Question 12

Thermoluminescence dating

Answer 12

Technique used to date crystalline materials by measuring the density of trapped electrons in crystal lattice

Question 13

Bio stratigraphy

Answer 13

Uses the combination of other animal fossils found at a particular site to determine hoe old it is

Question 14

Fossils are found in

Answer 14

commingled remains ( bits of teeth and bones)

Question 15

What makes a primate a primate

Answer 15

Grasping hands and feet
Nails instead of claws
Forward facing eyes encased in bone
Hand limb dominated locomotion 
Relatively large brain 
Generalized teeth
2-1-3-3 maximum formula

Question 16

Climate change causes

Answer 16

Environment to change

Species will undergo micro evolution or macro evolution

Question 17

Evolution of early primates

Plesiadapiforms

Answer 17

Plesiadapiforms: 
earliest primate fossil
54 to 65 mya in Wyoming, Montana, New Mexico, and Colorado 
They have:
Grasping hands and feet 
Big toe
Had a tail
Eyes on the side of its head and low crowned molars
Fruit not insects

Question 18

Evolution of early primates

Eocene primates

Answer 18

Eocene primates: Adapids and Omomyids
During this time climate was shifting back and forth
Eocene 34-54 mya
Paleontologist found fossils that are unquestionably from primates
Earth warm and wet- tropical forests spread into N. America and Europe
Primates have evolved

Question 19

Characters of Eocene primates: Adapids and Omomyids

Answer 19

Forward facing eyes
Post orbital bar
Short snouts
Relatively large brains 
Nails instead of claws
Hand limb dominated locomotion

Question 20

Eocene/ Oligocene boundary

Answer 20

33-36 mya,

World was becoming slightly cooler and drier

Question 21

Earliest haplorrhines can be found in

Answer 21

North Africa and China

Question 22

Anthropoids are found in

Answer 22

Egypt

Question 23

Oligopithecids

Answer 23

Old world monkeys and apes 2-1-2-3

Question 24

Parapithecids

Answer 24

New world monkeys 2-1-3-3

Question 25

Apes and old world monkeys diverged from

Answer 25

A common catarrhine ancestor

Question 26

Miocene

Answer 26

5-23 mya

Warm and wet, became cool and dry over time

Question 27

Apes versus monkeys

Answer 27

Apes have no tail
Forelimb suspensions 
Short, stiff lower back
Mobile joints
Long arms and fingers 
All of these adaptations for locomotion leave their signature on the skeleton, and so are identifiable in the fossil records.

Question 28

Morotopithecus

Answer 28

The earliest apes
Suspensory adaptations, or being able to hang from beneath a branch, is key hominoid feature.
First evidence in the fossil records for an ape that has adaptations for suspensory locomotion is Morotopithecus

Question 29

Morotopithecus

Answer 29

Uganda
20 million years old
Oldest ape?
Face and teeth ape like
Mobility at shoulders 
Stiff lower back 
Femur indicates slow climbing

Question 30

Proconsul

Answer 30

Africa:17-23 mya
Frugivorous
Forest environment 
Ape like skull and teeth 
Monkey like postcrania ( neck down very different)
Quadrupedal, non suspensory

Question 31

Miocene ape evolution

Answer 31

Early and middle Miocene of Africa, apes diversified and flourished
Lots of fossil evidence
Skull and teeth ape like
Neck down, more like monkeys without tails.

Question 32

Middle Miocene

Answer 32

10-15 mya
Apes had spread through out Eurasia ( Spain, France, Germany, Pakistan and Thailand)

Not found in Africa this time. Why.
Researchers haven’t found the Miocene apes fossils
Apes migrated to Eurasia due to ecological reasons

Question 33

Earth became planet of the apes during

Answer 33

The Miocene

Question 34

Late Miocene ape evolution

Answer 34

During the late Miocene 5-10 mya the climate continue to dry and cool
Apes that occupied the forest go extinct
Fossil record between 5 to 10 mya years ago is small
Genetic comparisons between humans, chimpanzees and gorillas indicate that the last common ancestor that we share with the African apes lived between 8 to 10 mya
After the gorilla linage branched, we continued to share a common ancestor with chimpanzees until about 5 to 7 mya
Thus , this is the key time for understanding what our shared ancestor with chimps and gorillas was like.

Question 35

Understand how fossils form and how this skews our understanding of species timelines and relationships.

Answer 35

-Most fossils form when organisms die and are buried in sediment. Fossils are named (molds, casts, preserved remains, or petrified) based on the way they look and how they were formed.
Molds- are hollow spaces where an organism or part of the organism once was.
Casts -are copies of the shape of the organism that made the mold (ice cubes would be molds and trays are casts, for example).
Preserved remains -are organisms that are preserved in other substances (rock, sediment, ice, amber, etc.).
Petrified fossils -are fossils that have been soaked in water and turned to rock.
Scientists determine fossil age by using relative dating (what layer it is in in rock) or radioactive dating (finding the age based on the radioactive elements around the fossil and how much is left compared to the nonradioactive element).