Dating, the Leakeys, Laetoli, and Lucy Flashcards Preview

Archaeology > Dating, the Leakeys, Laetoli, and Lucy > Flashcards

Flashcards in Dating, the Leakeys, Laetoli, and Lucy Deck (22)
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0
Q

Paleolithic

A

Crudely divided into several periods (relative dating)

  • 1.8 million years-200,000 years: lower paleolithic
  • 2-5 million years: middle paleolithic
  • Upper paleolithic = humans
1
Q

Dating

A

5-7 million years ago: humans and chimps diverge

  1. 4 million years ago: Hominin bipedalism
  2. 3 million years ago: first evidence of tool use
  3. 8-7,000 years: absolute dates
2
Q

Absolute Dating techniques

A

Dendrochronology, radiocarbon, optically stimulated luminescence, therma-luminescence, electron spin resonance, geomagnetism, and radiopotassium

3
Q

Dendrocchronology

A

Annual growth bands in tress

4
Q

Radiocarbon

A

Decay of C14

5
Q

Radio-potassium

A

K-Ar dating

  • Requires volcanic layers of ash (ash, basalt, etc.)
  • Measures 40K and 40Ar
  • Range of 100,000 to >5 million years old
  • “Setting the Clock”= heating vent releases Argon from molten lava; when the lava solidifies it means it has a lot of radioactive potassium; constant decay or Argon leads to accumulation in rocks
6
Q

Stratigraphy and K-Ar

A

Soil -> volcanic ash -> soil -> volcanic ash -> soil

  • Find two dates; first layer is under the spot human remains would be found second layers pile up (very important)
  • Can provide date range for non-volcanic sediments
7
Q

Early Hominins

A

Teeth were the only part of early Hominins found by archeologists (other parts destroyed by local animals; teeth too hard to digest)

8
Q

Thomas Huxley

A

Published Man’s Place in Nature (1863); similarities between human and ape skeleton’s
-Coined the concept of “missing link”: a species which links apes and humans (now there is many links)

9
Q

What makes humans?

A

Obligatory bipedalism, large brains, highly dextrous hands (opposable thumbs), non-divergent toes, enhanced verbal communication, and tool use

10
Q

Obligatory Bipedalism

A

Walking straight

11
Q

What makes apes?

A

Non-obligatory bipedalism, small brains, limited mobility in thumb, divergent toes, limited verbal communication, and limited tool use

12
Q

Non-obligatory Bipedalism

A

Walking bent

13
Q

Family “Bush”

A

Divergence, split offs, and a lot of common ancestors/relatives
-Hominin, lumpers, and splitters

14
Q

Hominins

A

All modern and fossil human species since the split of chimps

15
Q

Lumpers

A

Collapse species into one category

16
Q

Splitters

A

Split fossils into new species of genes (in between)

17
Q

Ardipithecus Ramdidus

A

Mixture of human and chimp features, bipedal walking, aboral adaptations (indication of climber due to long arms), divergent toes (grasping and climbing, not running), and reduced sexual dimorphism (females aren’t smaller than males)

18
Q

“Ardi”

A

Tim White (2009), Aramis, Ethiopia

  • Most complete early Hominin
  • 4.4 million years old
  • Female; weight: 110 lb (50 kg) height: 4 ft (120 mm)
20
Q

“Lucy” (Lucy in the Sky with Diamonds)

A

Donald Johanson discovered complete specimen (1974), Hadar, Ethiopia)

  • 3 million years old
  • Most complete specimen of A. Afarensis
  • Pelvis designed for bipedal locomotion; bowl-shaped pelvis
21
Q

Laetoli footprints

A

Mary Leaky, Tanzania (1976)

  • Evidence of bipedalism
  • 3.8-3.5 million years old
  • Footprints discovered by A. Afarensis
22
Q

Australopithecus Afarensis

A

Pronounced Sexual dimorphism (females smaller than males), long arms (climber) relative to legs, smaller cranial capacity (compared to chimps),

  • Females = weight: 55 pounds (25 kg) height: 3.5-4 ft (1-1.2 mm) brain: 380 cc
  • Males = weight: 110 lb (50 kg) height: 5 ft (1.5 m) brain: 480 cc (similar to chimps)