1. timer
Warm up: 1. What are the characteristics of minerals? 2. What type of chemical bond forms between positive and negative ions?

2. 1. What are the characteristics of minerals?
Color
Streak
Luster
Crystal form
Hardness
Cleavage
Fracture
Density
Other – distinctive properties
2. What type of chemical bond forms between positive and negative ions?
Ionic bonds where electrons are taken creating an ion where the opp. + and - Attract

3. History of Earth

4. How the Universe Started
Starting from the beginning:
The leading theory on how the universe started:
The Big Bang Theory:
the Universe came into being about 15 billion years ago, with the sudden appearance of all the matter and energy in the Universe as a single very hot and dense point
How this happened, and what came before, is a matter of complete speculation. Our history began then, and we have no scientific evidence of anything before then.

5. How did the Earth form?
Cosmic debris became attracted to one another (Gravitational pull due to size and proximity)
It took over 100 million years to form Earth
Nebular hypothesis
H and N gas formed the atmosphere: NO OXYGEN
Earths atmosphere has changed a LOT over the last 4 billion years
The first atmosphere lacked oxygen and only started accumulating oxygen AFTER the evolution of photosynthetic organisms.

6. Early Earth… Earth is 4.6 BILLION years old
3.8 billion years ago Earth cooled enough for water to remain liquid – this is VERY important, because life originated in the water
1st life approx. 3.8 BYA

7. What is the Earth’s time scale?
The Geological time scale is a record of the life forms and geological events in Earth’s history.
Scientists developed the time scale by studying rock layers and fossils world wide.
Radioactive dating helped determine the absolute divisions in the time scale.

8. FOUR Eras we will cover…
Divisions of Geologic Time
Eon is broken down into Eras, Eras are broken down into periods which are broken down into Epochs.
Eon> Era> Periods> Epoch
FOUR Eras we will cover…
PRE-CAMBRIAN (can also be an Eon)– 88% of earth’s history
4500 MYA (4.5BYA)… lasted 3956 million yrs
Paleozoic (ancient life)
544 million years ago…lasted 300 million yrs
Mesozoic (middle life)
245 million years ago…lasted 180 million yrs
Cenozoic (recent life)
65 million years ago…continues through present day

9. Today…
Today we are in the Holocene Epoch of the Quaternary Period of the Cenozoic Era.
Which unit is the largest?
Which unit is the smallest?

10. Summary of Earth History4 3
Summary of Earth History 2 1

11. PRE-CAMBRIAN Age of the Bacteria
Prokaryotes dominated the Earth for most of its history. Believed to be the first life forms.
Oldest traces of life: 3.5 – 3.8 BYA.
(so bacteria is 3.5 BYOld)
Multicellular eukaryotes are less than 1 BYA.
PRE-CAMBRIAN = 4.5 Bya to 543 BYA
Bacteria can live under a much wider variety of conditions than eukaryotes. They use many different sources of energy and carbon, and they can grow at very high temperatures, high pressures, acidic conditions, etc.
The atmosphere of the primitive Earth had NO OXYGEN

12. Paleozoic Era (Ancient Life)
The Cambrian period is the 1st period of the Paleozoic Era. “Age of the Trilobites”
Explosion of life in the oceans began during this era.
Most of the continents were covered in warm, shallow seas.
Invertebrates were dominate - Trilobites
Fish emerged during this time
Fish led to the arrival of amphibians
The end of the Paleozoic era is called the “Age of Amphibians”
Early land plants including mosses, ferns and cone-bearing plants.
The early coal forming forests were also formed during this time.
Paleozoic Era = 543 BYA to 248 BYA

13. Paleozoic Era
Much of the limestone quarried for building and industrial purposes, as well as the coal deposits of western Europe and the eastern United States, were formed during the Paleozoic.
The Cambrian (beginning) opened with the breakup of the world-continent Rodinia and closed with the formation of Pangaea, as the Earth's continents came together once again.
This event is thought to have caused the climate changes that led to mass extinction event.
The Appalachian mountains were formed during this time.
Limstone uses cement and mortar. Pulverized limestone is used as a soil conditioner to neutralize acidic soils. It is crushed for use as aggregate—the solid base for many roads as well as in asphalt concrete.
The continents have come together and separated multiple times

14. Paleozoic Era
At the end of the Paleozoic, the largest mass extinction in history wiped out approximately 90% of all marine animal species and 70% of land animals.
Possible causes of this Mass Extinction Event
Lowering of sea levels when the continents were rejoined as Pangaea (convergent boundary)
Increased volcanic activity (ash and dust)
Climate changes – cooler climate
Based off the graph what is the general trend of life on Earth?

15. Paleozoic Era Trilobites Brachiopods
Lived in Earth’s ancient seas
Extinct before the dinosaurs came into existence
Cambrian Period is know as the “Age of the Trilobites”
Marine animals that resemble clams.

16. Paleozoic Era Early Fish Early Land Plants
Early fish did not have jaws.
Some species of sharks were in existence at this time.
Frilled Shark that was found in Japan in January This shark was considered a “living fossil”
Early Land Plants
Mosses
Ferns
Cone bearing plants

17. Mesozoic Era – Middle Life
At the beginning of this era the continents were joined as Pangaea.
Pangaea broke up around the middle of this era.
Reptiles became the most abundant animals because of their ability to adapt to the drier climate of the Mesozoic Era.
Skin maintains body fluids
Embryos live in shells
Bacteria is still very very abundant!!
Its everywhere and can be argued to this day they are the dominate life form…
Mesozoic Era = 248 BYA to 65 BYA

18. Mesozoic Era Dinosaurs were also very active in this era.
First small dinosaurs appeared in the Triassic Period.
Larger and more abundant dinosaurs appeared in the Jurassic Period.
Small mammals and birds evolved during this era.
The mammals were small, warm-blooded animals. Hair covering their bodies.
These characteristics help them survive in changing environments.

19. Mesozoic Era
The main plant life of this time were Gymnosperms or plants that produce seeds, but no flowers.
Pine Trees
Flowering plants appeared during the END of this era.

20. Mesozoic Era
This era ended with a mass extinction event about 65 million years ago.
Many groups of animals, including the dinosaurs disappeared suddenly at this time.
The leading theory is that event was caused by a comet or asteroid colliding with the Earth.

22. Mesozoic Era – Mass Extinction Event
How does an asteroid cause the whole planet to change…
Asteroid or Comet collides with Earth.
Huge cloud of smoke and dust fills the air
Blocks out sunlight
Plants die
Animals that eat plants die
Animals that eat plant-eaters die.
However, not all forms of life died during this event. Many animals that you see today are descendants from the survivors of this extinction event.
This includes mammals the group of animals HUMANS are!! If the dinosaurs never went extinct humans many never have evolved

23. Dinosaurs
Mesozoic Reptiles
Mesozoic Era

24. Cenozoic Era – Recent Life
Cenozoic Era = 65 BYA to today
Cenozoic Era – Recent Life
Began about 65 million years ago and continues today!!!!!
Climate was warm and mild.
Marine animals such as whales and dolphins evolved.
Mammals began to increase and evolve adaptations that allowed them to live in many different environments – land, air and the sea.
Many mountain ranges formed during the Cenozoic Era
Alps in Europe and Himalayas in India; Rocky Mountains in the USA
Growth of these mountains may have helped to cool down the climate
Ice Ages occurred late in the Cenozoic Era (Quaternary Period).
As the climate changed, the animals had to adapt to the rise and fall of the oceans caused by melting glaciers.
This era is sometimes called the “Age of Mammals”

25. Cenozoic Era Marine animal examples: Land animal examples:
Algae, Mollusks, Fish and Mammals
Land animal examples:
Bats, Cats, Dogs, Cattle and Humans
Our species of humans first began to evolve nearly 200,000 years ago in association with technologies not unlike those of the early Neanderthals.(during the most recent period – Quaternary).
Flowering plants were now the most common plant life.

26. How much time was each era….

27. 11:59:20 Early humans appear
12:00 The formation of Earth
11:00 Mammals
appear
10:30
Reptiles
appear
9:15 Fish, vertebrates
appear
6:30 Life forms
appear (bacteria)

28. History of Earth
Making a time line!!