From Tree to Bog: The Evolution and Pickling of Human Beings

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From Tree to Bog The Evolution and Pickling of
Human Beings
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The Big Questions of Human Evolution

• What spurs the evolutionary process?
• How did humans gain cognitive powers?
• What motivated early human migration?

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Background

• 4.5 billion B.C. Planet Earth formed
• 4.4 million B.C. Earliest known hominid
  fossils
• 3.2 million B.C. Australopithecus afarenis (
  Lucy)
• 2.5 million B.C. Homo habilis
• 1.8 million B.C. Homo erectus
• 100,000 B.C. First modern Homo sapiens
• 15,000 B.C. Migrations across Bering Straits

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Basic Ideas

• Ape gt Australopithacus gt Homo
• Homo
• Habilis skillful
• Erectus Upright
• Sapien Wise
• Hominid having hominine features
• Bipedalism
• Human body proportions
• Loss of body hair
• Omnivory
• Tool-making

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Lucy was a late Australopithecus found in
Africa. Early evidence of link between humans
and apes.
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What causes evolution?

• Characteristics suited to environments
  are passed on
• Pressures from climate change causes adaption,
  migration, and extinction

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Case Study From Bipedalism to Cognitive Powers

• Australopithecus has small skeletal structure and
  cranium
• Bipedal but still very arboreal trees as
  sources of food and refuge
• Infant is self-sufficient very shortly after
  birth
• Experienced evolutionary stasis for 1.5 M.y.a.
  which indicated stable environment and little
  climate change

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Climate change

• Ice Age 2.5 M.a. transformed habitats world-wide
• In Africa forested areas become dry grasslands
• Trees are less available, Australopithecus forced
  to spend more time on ground

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Results Australopithecus into Homo

• Development of bipedal skills in relation to
  large predators and food sources
• Mothers no longer required to climb, spend more
  time caring for infant
• High in utero brain growth rate extends into
  post-natal period

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Migration Related to Climate

• Homo skeleton found in Kenya tall linear
  structure suited to long-distance travel and warm
  weather spread to north-east Africa during warm
  intervals
• Short compact physiques and skeletal structures
  of Neanderthals adapted to low temperatures and
  aided survival
• Crossing of Bering Strait land bridge made
  possible by ice age that created huge glaciers
  and lowered sea level

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Travels of the First Humans
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Muddy WatersQuestions about Bogs

• What are bogs?
• How are bogs formed?
• How do they preserve materials?
• What geological formations and materials do they
  produce?

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What are bogs?

• Bogs and fens are two forms of peatlands
• Peatlands are accumulations of peat
• Peat soil composed of partially decomposed dead
  plants that accumulate in waterlogged areas
• Peat is 90 water and 10 solid material

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How were bogs formed?

• Bog formation began at the end of the last
  glaciation about 100,000 years ago
• Shallow lakes were left behind by retreating ice
• Major bog formations are found in the British
  Isles, the Netherlands, Germany, Denmark,
  Belgium, and Switzerland

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The formation of a raised bog.
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What do bogs produce?

• Rich and ancient habitats of biological diversity
• Carbon-rich peat (cut for fossil fuel)
• Lithification produces coal and clues to earth
  history (Pennsylvanian formation)

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How do bogs preserve materials?

• Acidic with a pH of 3.2 to 4.2, caused by
  Sphagnum (bog mosses)
• Prevents growth of micro-organisms that cause
  decay of flora and fauna
• Preserves human bodies, turning skin to leather
  and preserving organs and skeleton

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What bogs can tell us

• Plant and animal fossils give information about
  community persistence, stability, and response to
  major climate disruptions
• Rock formations tell about climate (ie,
  alternating wet-dry depositions)
• Any biological or geological turnovers offer
  evidence about climate change

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Bodies in the Bog
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Clues to the Past
Bodies can tell us about the habits, lifestyles,
and civilization of early humans, which can in
turn give us clues about past climate patterns