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(5 BYA) Solar System
The solar system was a swiriling mass of gas and dust. -
(4.6 BYA) Earth's Growth
The Earth grew larger as debris was gathered, the sun was formed and planets formed due to repeated collisions of space debris. -
(2.2 BYA) Earth
Earth appeared much as it does today, volcanoes emit gas, forming an atmosphere while other features shape the Earth as well. -
(4 BYA) Layers of the Earth
By studying the layers of the Earth, scientists can estimate the age of Earth based on the layers of sedentary rocks . It is officially believed that the Earth was formed 4 billion years ago. -
(4 BYA) Archaea
Archaea first populated the Earth 4 billion years ago. -
(3.5 BYA) Fossils
Fossils of Stromalites from 3.5 billion years ago show photosynthetic qualities. -
(3 BYA) Life
Some forms of life had become photosynthetic -
(2.2 BYA) Atmosphere
Earth appears much as it does today. Volcanos emit gas to form atmosphere. -
(2 BYA) Levels
O2 levels reached the same levels as they are today. -
(2-1.5 BYA) Prokaryotics
A small type of areobic prokaryotic was engulfed by and began to live and reproduce inside of a larger anaerobic prokaryotic. -
(1 BYA) Ozone
Ozone layer was formed. It protected organisms from harmful UV rays so they could exist on land. -
(1600-1700) Experiments
Hooke studied dead cork cells using a light microscope. Redi’s then used meat with maggots and flies to show that maggots did not occur in the sealed jar where maggots weren’t living. The main idea of his experiment was that living things come from other living things. -
(1700-1800) Sidney Fox
The first amino acids were transported to some cliffs near a volcano right after there formation in their primordial ocean. Fox combined purified amino acids by heating them in a dry environment. -
(1700-1800) Lazzaro Spallanzani
He researched the topic of spontaneous generation. His experiments dealt with boiled chicken broth in flasks sealed off from the air. Spallanzani used his evidence to conflict spontaneous generation and paved the road for Pasteur. -
(1800-1900) Louis Pasteur
Pasteur essentially remaid the chicken broth experiement however there was a major cahnge in his flask. The neck was curved in an S-shape to ensure no particles could reach the broth. When no bacteria grew, many scientists took that as the final sign, putting an end to the spontaneous generation theory. -
(1900-Present) Oparin's Hypothesis
Oparin's hypothesis is what Urey and Miller were trying to prove. It states that on our primative Earth, chemical reactions between inorganic elements resulted in organic compounds. This process is said to have been the orgin of life. Many scientists have looked into this hypothesis and have agreed with Oparin.
