The Beginning to the Precambrian Eon
Precambrian Era: https://www.youtube.com/watch?v=8ZqZ0UoHPjc
The Evolution of Animals
History of Life on Earth
TAKE 2
Complex Life Guided Notes
Animal life did not appear in the fossil record until about 542 million years ago.
Complex Life Guided Notes
These early animals were soft-bodied and still relatively simple compared to the complex animals seen today.
Complex Life Guided Notes
Sneak Peek Guided Notes
https://www.youtube.com/watch?v=ice47loNmsc
Complex Life Guided Notes
542 million years ago, animal life began to evolve at an extremely rapid rate of geologic time.
Complex Life Guided Notes
This period of evolution was so significant it marks the beginning of an entirely new eon….. the largest division of geologic time.
Complex Life Guided Notes
This new eon is called the Phanerozoic Eon, which includes the present day.
Cambrian Explosion Guided Notes
This period of evolution, starting with the Cambrian Period, was so rapid it is referred to as the “Cambrian Explosion.”
Cambrian Explosion Guided Notes
Life seemed to evolve more rapidly and with greater diversity than ever before in Earth’s history.
Cambrian Explosion Guided Notes
Cambrian Explosion Guided Notes
The Cambrian Explosion lasted about 20 million years and resulted in most of the major animal groups that exist on Earth today.
Cambrian Explosion Guided Notes
All Cambrian Period animals were marine organisms but their fossils are found at the tops of the Rocky Mountains in Canada.
Cambrian Explosion Guided Notes
REMEMBER –
Fossils show changes in past environments.
Internal Digestion Guided Notes
Internal digestion in animals also developed during the Cambrian Explosion, and the world saw its first predator-prey relationships.
Internal Digestion Guided Notes
RAPID EVOLUTION
Survival of the Fittest!
Internal Digestion Guided Notes
Prey: (have to pass on genetics)
Internal Digestion Guided Notes
Predator: (have to pass on genetics)
Internal Digestion Guided Notes
Now!!!! We have hard body parts to fossilize.
Vertebrates Guided Notes
The Rise of the Vertebrates
Vertebrates Guided Notes
Some animals evolved to had a nerve cord that ran along their backs. These animals eventually evolved into the first animals with backbones…
Vertebrates Guided Notes
…the vertebrates. The backbone provided a new type of body plan that enabled animals to occupy many new niches.
Vertebrates Guided Notes
Earliest Vertebrates were simple fish:
Vertebrates Guided Notes
Hagfish & Lampreys
Still alive today!!!!
Vertebrates Guided Notes
Vertebrates Guided Notes
Vertebrates Guided Notes
Fish soon evolved jaws that enabled them to feed more effectively.
Vertebrates Guided Notes
These first fish were quite similar to modern sharks.
Vertebrates Guided Notes
Fish with hard bones evolved at about this time.
Vertebrates Guided Notes
Vertebrates Guided Notes