For the first half of the period, students completed the evolution case study quiz. After completing the quiz, we transitioned from learning about microevolution to macroevolution.
Natural selection is only one part of microevolution. There are three other components, that because of time, we were not able to study in depth. These are: mutation, migration and genetic drift (random loss of genetic variation). When these four parts components are combined with a substantial amount of time, macroevolution can occur.
The first hurdle in learning about macroevolution is understanding the immense amount of time involved. To help us, students hypothesized about the appearance of life on Earth by making a model timeline.
Our timeline was only 4.6 meters long. Tomorrow we will be creating a larger timeline on campus. Your homework is to research your two assigned events. Hopefully the weather will cooperate.
Ivan your assigned events are: Neanderthals and Mississippi River Formation
Carlo your assigned events are: Formation of the Himalayas and Pictograms (written communication)
Below are the events which will be placed on the timeline:
Geological Events: When (in millions of years)
Pleistocene Ice Age 1.6
Land bridge between North and South America 5.7
Antarctic Ice cap 24
Mississippi River 35
Separation of Antarctica and Australia 50
Formation of the Himalayas 55
Formation of the Rocky Mountains 70
Breakup of Pangea 165
Oxygen building up in atmosphere 600-2500
Formation of the earth 4600
Biological Events
Pictograms (written communication) .005
Modern humans .04
Neanderthals .10
Manufactures stone tools 2.5
Lucy 3.2
Hominids 4.0
Monkeys 35
Primates 65
Flowering plants 140
Birds 150
Mammals 225
Dinosaurs 235
Reptiles 300
Seed producing plants 350
Amphibians 360
Land animals 400
Land plants 430
Vertebrates 520
Animals with hard shells 590
Soft bodied animals 680
Multicellular organisms 1000
Eukaryotes 1400
Bacteria 3500
Note: 1 billion equals 1000 million
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