1. The History of Life on Earth

2. LIFE…

3. Formation of the Earth
Earth was formed approx billion years ago out of the solar nebula.
Initially molten, the outer layer cooled to form a crust about 4.3 B.Y.A. as water was brought to Earth by meteors.
By 3.9 B.Y.A. Earth had cooled enough to form oceans.

4. Formation of the Earth
Out gassing and volcanic activity produced the primordial atmosphere consisting of water vapor, carbon dioxide, hydrogen, ammonia, methane, and other gasses.
The primordial ocean was most likely made up of water, with methane,
ammonia, hydrogen, sulfur, and carbon dioxide.
No free oxygen in the
atmosphere or oceans at
this time.

5. First Life on Earth- Biogenesis
Life – metabolism and reproduction, growth and response to stimuli (adaptation).
Proto cells: cell-like spheroid formed from proteinoids (chained groups of amino acids).
Proto-cells containing RNA may have been the first cellular life forms on Earth. (3.8 B.Y.A.)

6. The First Cells
Prokaryotic cells (bacteria): Cells without a membrane-bound nucleus. ( B.Y.A.)
Archaebacteria- first autotrophs, blue-green algae (supplied the first oxygen to the atmosphere)
Genetic material is in a circular loop called a plasmid

7. The First Cells
Eukaryotic cells: cells with a membrane-enclosed nucleus.
Developed approx. 2 billion years ago
Include all complex cells and make up all multi-cellular organisms.
Animals, plants, fungi, and protists are eukaryotes.

8. The Precambrian Proterozoic Eon – 2500 to 543 mya
Paleoproterozoic Era – 2500 to 1600 mya
Stable continents
2400 – 2100: Huronian ice age
Mesoproterozoic Era – 1600 to 900 mya
Formation of supercontinent Rodinia
Eukaryotic cells appear
1200 mya: spore/gamete formation (sexual reproduction)
Photosynthetic organisms proliferate, oxygen above 10%
Formation of the ozone layer
950 mya: start of Stuartian-Varangian ice age

9. The Precambrian Proterozoic Eon – 2500 to 543 mya
Neoproterozoic Era – 900 to 643 mya
Earth day is 18 hours long
Formation of a supercontinent
Cryogenian Period – 850 to 635 mya
750 mya: End of last magnetic reversal
650 mya: mass extinction #1 of 70% of dominant sea plants.

10. 30 Seconds 10 Time’s Up! 3 Minutes 1 Minute 4 Minutes 1 2 5 2 Minutes
Bellringer Wed, 02/18
What is a mass extinction? (Educated guess of look it up!)
Name 3 things that happened during the Precambrian Era/Eon!
Reminders: HW #4 due Fri, LAB FEE anytime, Quiz Fri Grade Progress Reports go out next week!
30 Seconds 10
Time’s Up!
3 Minutes
1 Minute
4 Minutes 1 2 5
2 Minutes 8 9 7 6 4 3

11. TIME…
EON
ERA
PERIOD
EPOCH

12. Phanerozoic Eon (543 mya to present)
Paleozoic Era – 543 to 251 mya
Vendian (Ediacaran) Period – 635 to 543 mya
570 mya: end of Stuartian-Varangian ice age
Soft-bodied organisms developed (first jellyfish)
Cambrian Period – 543 to 490 mya
Most of the major groups of animals first appear
530 mya: Animals with shells appeared

13. Phanerozoic Eon (543 mya to present)
Paleozoic Era – 543 to 251 mya
Ordovician Period – 490 to 443 mya
Diverse marine invertebrates, first vertebrates appear, first green plants and fungi on land
450 mya: start of Andean-Saharan ice age
443 mya mass extinction #2 of many marine invertebrates.
Silurian Period – 433 to 417 mya
End of Adean-Saharan ice age, stabilization of Earth’s climate
Coral reefs appeared, first fish with jaws, spiders, centipedes and plants appear on land.

14. Phanerozoic Eon (543 mya to present)
Paleozoic Era – 543 to 251 mya
Devonian Period – 417 to 354 mya
Ferns and seed-bearing plants appeared, first amphibians
Wingless insects and vertebrates appear on land
Pannotia fragmented into Laurasia and Gondwana
Atmospheric oxygen level about 16%
374 mya: mass extinction #3 of 70% of marine species

15. Phanerozoic Eon (543 mya to present)
Paleozoic Era – 543 to 251 mya
Carboniferous Period – 354 to 299 mya
Mississippian Epoch – 354 to 318 mya
Karoo ice age, large primitive trees, vertebrates appear on land, first winged insects
Pennsylvanian Epoch – 318 to 299 mya
First reptiles, atmospheric oxygen over 30%, giant arthropods, deposits of coal form in Europe and Asia.

16. Phanerozoic Eon (543 mya to present)
Paleozoic Era – 543 to 251 mya
Permian Period – 299 to 251 mya
Formation of the supercontinent Pangaea, Earth is cold and dry
Conifers (pine trees) appear
260 mya: end of Karoo ice age
Oxygen levels drop from 30% to 12%
251 mya: Great Permian-Triassic mass extinction #4 – 90% of ocean dwellers and 70% of land plants and animals.

17. PANGEA

18. Phanerozoic Eon (543 mya to present)
Mesozoic Era – 251 to 65 mya
Triassic Period – 251 to 200 mya
Breakup of Pangea starts
First dinosaurs appear, first evidence of mammals
201 mya: mass extinction #5 20% of marine animals

19. Phanerozoic Eon (543 mya to present)
Mesozoic Era – 251 to 65 mya
Jurassic Period – 200 to 145 mya
Earth is warm – no polar ice
Age of the dinosaurs: giant herbivores and vicious carnivores.
North America splits from Europe.
150 mya: First birds (archaeopteryx) appear

20. Phanerozoic Eon (543 mya to present)
Mesozoic Era – 251 to 65 mya
Cretaceous Period – 145 to 65 mya
Africa and India split from Antarctica, South America splits from Africa
Flowering plants, crocodiles appear, modern mammals and birds developed.
70 mya: T-Rex thrived
65 mya: Meteor impact, Yucatan, Mexico – mass extinction #6 of dinosaurs.

22. Phanerozoic Eon (543 mya to present)
Cenozoic Era – 65 mya to today
Tertiary period – 65to 1.8 mya
Paleocene Epoch – 65 to 54.8 mya
Appearance of placental animals
Formation of Rocky Mtns, major global warming
Eocene Epoch
– 54.8 to 33.7 mya
India and Asia collide forming the Himalayas, Australia separates from Antarctica.
Small modern mammals appear.

23. Phanerozoic Eon (543 mya to present)
Cenozoic Era – 65 mya to today
Tertiary period – 65 to 1.8 mya
Oligocene Epoch – 33.7 to 23.8 mya
Start of Pleistocene ice age
Appearance of grasses, elephants, camels, early horses.
Miocene Epoch – 23.8 to 5.3 mya
The plants and animals of the Miocene were fairly modern.
Mammals and birds were well-established. Whales, seals, and kelp spread.

24. Phanerozoic Eon (543 mya to present)
Cenozoic Era – 65 mya to today
Tertiary period – 65to 1.8 mya
Pliocene Epoch – 5.3 to 1.8 mya
Accumulation of ice at the poles
Spread of grasslands, rise of long-legged grazing animals
2.4 mya: Homo habilis appears- tool making humanoids

25. Phanerozoic Eon (543 mya to present)
Cenozoic Era – 65 mya to today
Quaternary Period – 1.8 mya to today
Pleistocene Epoch – 1.8 mya to 10,000 yrs ago
Homo erectus moves out of Africa
Presence of large land mammals and birds
Global cooling and glaciation
Neanderthals – 500,000 yrs ago
Homo sapiens – 200,000 yrs ago

26. Phanerozoic Eon (543 mya to present)
Cenozoic Era – 65 mya to today
Quaternary Period
1.8 mya to today
Holocene Epoch – 11,600ya to today
Development of agriculture and domestication of animals starts
9,000 ya: metal smelting found
5,500 ya: wheel invented
5,000 ya: first writing
4,500 ya: Pyramids in Egypt
2,000 ya: Christian Era starts
250 ya: industrialization Age
50 ya: First Space Travel