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Wize University Biology Textbook > Tetrapods (Four Limbs)

Humans

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Humans



Overview of Humans

  • Characteristics
  • Stand upright
  • Much larger brain
  • Language, art, tools
  • DNA is 99% similar to chimpanzees
  • 1% represents substantial changes
  • Early Hominins: extinct species that are more closely related to humans than chimps
  • Earliest fossil ~6.5 MYA
  • Show gradual progression to more upright
Photo by Tkgd2007 | CC BY
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Australopiths

  • 2-4 MYA
  • "lucy" discovered in africa
  • Bipedalism: walking on two legs
  • Became more efficient, fewer limbs required
  • Tool use
  • Found cuts on bone ~2.5 MYA
  • Indicates stone knives


Photo by Tim Evanson | CC BY


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Homo

  • Genus that contains humans
  • Homo habilis
  • "Handy man"
  • 2.4 - 1.6 MYA
  • Sharp stone tools
  • Homo ergaster
  • 1.9 - 1.5 MYA
  • Larger brain
  • Decreased sexual dimorphism
  • Used to be considered Homo erectus
  • Homo neanderthalensis
  • Neandrathals
  • Larger head than modern humans
  • Buried dead
  • Tools from stone and wood
  • 350,000 - 30,000 YA
  • Gene flow with humans
  • Homo sapiens
  • Modern humans
  • Oldest fossils from Africa 195,000 - 160,000 YA
  • More slender, less pronounced brows








Photo by E. Daynes | CC BY
Photo by Wolfgang Sauber | CC BY
Photo by Bacon Cph | CC BY
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Human Migration

Numbers are years before present


Practice: Humans

Bipedalism developed first in what group of hominids?

Practice: Humans

True or False:
There was no contact between Neanderthals and Homo sapiens.
Extra Practice
1. On which continent did Homo sapiens first evolve and spread from?
2. We have good evidence of gene flow to Homo sapiens from one other Homo species, which one?
3. I was around from 2.5-1.5 MYA and I was the first to used tools, who am I?
Falsifiable Statements
Which of the following statements are falsifiable?
1. All mammals have a vestigial structure relating us to reptiles
2. Mice are evolutionarily more closely related to chimpanzees than humans
Evolutionary Theory
The last common ancestor between humans and chimpanzees was 6 million years ago. The last common ancestor of humans and mice was 80 million years ago. Which of the following can be concluded from this information?
1. Chimps and humans are more closely related through evolution than mice and chimps
2. Similar developmental stages between human and mice are due to convergence
Which of the following is a vestigial structure?