1. Catastrophic Events
8.E.6A.3 Construct explanations from evidence for how catastrophic events (including volcanic activities, earthquakes, climate changes, and the impact of an asteroid/comet) may have affected the conditions on Earth and the diversity of its life forms

2. Mass Extinctions
Impacts, climate changes, and volcanism can create rapid and quick changes to environmental conditions
Many Organisms cannot adapt to these changes resulting in the extinction of those species

4. Impact of an asteroid or comet
Earth’s atmosphere protects the planet from many of the meteors that enter it resulting in the burning up before striking the surface
There is evidence of many impacts throughout Earth’s history
Impacts have had both local and large-scale effects on the environment and biodiversity
At the end of the Mesozoic Era, a large asteroid or comet hit Earth
Caused dust and smoke to rise into the atmosphere
The Dust and smoke caused climatic changes, death of plants, animals died because of lack of vegetation
There is a crater off Mexico’s Yucatan Peninsula which is dated about 65 mya

6. Climatic changes Earth’s environments have many different climates
Climate is an ever-changing condition
Earth’s life forms were influenced by the climates produced by the forming atmosphere and oceans
Life on land developed and thrived in the tropical climates and warm shallow seas during the Paleozoic Era
In the Paleozoic, there were different land environments and sea levels changed and new life forms developed
Some life forms could not adapt or find suitable conditions, especially many marine species

7. Cont.
During the Mesozoic Era, many climatic changes occurred due to plate tectonics and movement of landmasses
Plants and animals that survived through this time had structures and systems that allowed for greater adaptations
Seed coverings for plant seeds
Protective body coverings
Constant internal temperature for animals

8. Cont. In the Cenozoic Era, Climate conditions continue to change
Major ice ages cause the climate to become much cooler as ice sheets and glaciers covered many areas of Earth
Many Mountain ranges formed causing climate differences due to elevation and due to location near those ranges

11. Volcanic Activity
Volcanic activity has been part of the nature of the changing planet
As continents collided and mountains built up, volcanoes formed
During the Precambrian time volcanic activity was one of the most natural events
Lava flows, ash clouds in the atmosphere, and heat made conditions for life extremely difficult
Volcanic activity continued to be common in the Paleozoic

12. Cont.
Rapid movement of tectonic plates in the Mesozoic Era and the collisions and subduction produced extensive Volcanic activity around plate boundaries
Plate boundaries are still the location of much of Earth’s volcanic activity
Very explosive volcanic activity can send ash and dust into the atmosphere where it is carried great distances around the Earth
The Sun can be blocked for long periods of time
Violent type of activity can disrupt many of Earth’s processes and ultimately the life forms that depend on those processes