Final Exam Study Guide Chapter 9 Flashcards Preview

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Flashcards in Final Exam Study Guide Chapter 9 Deck (35)
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1
Q

Continental drift

A

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

2
Q

Climate change

A

Cooling and drying trend over the last 20 million years

3
Q

Changing environment leads to

A

Adaptations

4
Q

Changing environments led to

A

Selection pressures

5
Q

How do scientists reconstruct ancient climates

A

-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.

6
Q

How do scientists know how old fossils are.

A

-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

7
Q

Carbon dating techniques

A
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
8
Q

Dating techniques: Clock in a Rock

A

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

9
Q

Uranium lead dating

A

Flowstones of caves

10
Q

Other dating methods

A

Thermoluminescence
Electron- spin resonance
Paleomagnetic dating

11
Q

Electron- spin resonance

A

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

12
Q

Thermoluminescence dating

A

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

13
Q

Bio stratigraphy

A

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

14
Q

Fossils are found in

A

commingled remains ( bits of teeth and bones)

15
Q

What makes a primate a primate

A
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
16
Q

Climate change causes

A

Environment to change

Species will undergo micro evolution or macro evolution

17
Q

Evolution of early primates

Plesiadapiforms

A
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
18
Q

Evolution of early primates

Eocene primates

A

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

19
Q

Characters of Eocene primates: Adapids and Omomyids

A
Forward facing eyes
Post orbital bar
Short snouts
Relatively large brains 
Nails instead of claws
Hand limb dominated locomotion
20
Q

Eocene/ Oligocene boundary

A

33-36 mya,

World was becoming slightly cooler and drier

21
Q

Earliest haplorrhines can be found in

A

North Africa and China

22
Q

Anthropoids are found in

A

Egypt

23
Q

Oligopithecids

A

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

24
Q

Parapithecids

A

New world monkeys 2-1-3-3

25
Q

Apes and old world monkeys diverged from

A

A common catarrhine ancestor

26
Q

Miocene

A

5-23 mya

Warm and wet, became cool and dry over time

27
Q

Apes versus monkeys

A
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.
28
Q

Morotopithecus

A

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

29
Q

Morotopithecus

A
Uganda
20 million years old
Oldest ape?
Face and teeth ape like
Mobility at shoulders 
Stiff lower back 
Femur indicates slow climbing
30
Q

Proconsul

A
Africa:17-23 mya
Frugivorous
Forest environment 
Ape like skull and teeth 
Monkey like postcrania ( neck down very different)
Quadrupedal, non suspensory
31
Q

Miocene ape evolution

A

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.

32
Q

Middle Miocene

A

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

33
Q

Earth became planet of the apes during

A

The Miocene

34
Q

Late Miocene ape evolution

A

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.

35
Q

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

A

-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).