5.5 : History of life

BS 5 - History of life
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Slide 1: Tekstslide
BiologieMiddelbare schoolvwoLeerjaar 3

In deze les zitten 10 slides, met tekstslides en 2 videos.

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BS 5 - History of life

Slide 1 - Tekstslide

  1. Created when remains of organisms do not decay
  2. Deposited layers of clay or sand cover the remains
  3. Bacteria unable to do their work - the process of decay is stopped
  4. Other layers of sand/clay cover the remains and over time mineralize

Slide 2 - Tekstslide

Slide 3 - Video

Geological timescale
This is the geological timescale.
  • Calendar of the creation of the Earth
  • Divided into time periods
  • Each with distinctive climate
  • Each characteristic types of plants and animals (fossils)

Slide 4 - Tekstslide

Geological timescale
  • Geological time scale: Division of the     Earth's history into geological eras.
  • Life on Earth evolved in these eras.
  • Each era is divided into periods. 
  • Periods can be divided into time slots
  • Numbers indicate time in millions of years ago.
  • You can see how many million years ago a period started and ended.

Slide 5 - Tekstslide

Animals on land
  1. First land plants = 500 mya
  2. Fish appeared around the same time
  3. First land animals = 450 mya
  4. Arthropods (centipedes in particular)
  5. Followed by amphibians and reptiles
  6. Reptiles were quite successful = dinosaurs  251 mya
  7. First mammals and birds appeared alongside dino
  8. Dinos wiped out 65 mya
  9. Meteor collision with earth - Created black cloud of dust that hung over the earth’s surface for years
  10. Darkened the sky = temp dropped = climate change
  11. Hominids appeared 3 mya
  12. Homo sapiens appeared 150,000 years ago

Slide 6 - Tekstslide

Slide 7 - Video

Kinship of species
  • Species that have a common ancestor are related - the have a degree of kinship
  • Longer ago the common ancestor = less closely related the species are
  • The figure shows a drawing of a branching tree of the development of the pig family.

Is the following statement true or false?

Cebochoerus is the ancestor of the whole pig family.

Slide 8 - Tekstslide

Similarity in structures
  • organs can have the same structure but very different functions
  • Most probably come from (derived) from the same original structure
  • These animals therefore probably have a common ancestor

Slide 9 - Tekstslide

Rudimentary organs

Slide 10 - Tekstslide