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(5 BYA) Formation of the Solar system
The solar system started out as a swirling mass of gas and dust. The swirling material was eventually held together by gravity and the sun was formed. This created heat and energy for organisms to survive. -
(4.6 BYA) Formation of the Earth
Earth began to form due to chunks of mass forming together due to gravity. It Grew consnatly by coliding with other large space debris.this happened because matter was floating around and they were bound to crash into eachother sometime, and once a big enough mass was formed, the mass started pulling things toward it, with gravity. -
(4 BYA) Age and Evolution on Earth
This is the age that the Earth is estimated to be. This age was found by studying layers of sedimentary rock in the earths crust, and carbon daing it. An Archaeal species, Methanosarcina, were thought to be the first cell based species that populated earth. It's important to know the age and first organisms on earth to create an accurate time-line of the earth. -
(3.5 BYA) First Fossils
Stuctures called stromatolites left fossils. These are the oldest fossils found to date. This happened because a sudden change in the environment allowed roch to be formed on, or over a dead organism and the carbon left and implant on the rock. fossils are found by using radiometric dating. -
(3 BYA) First self-reliant life forms
Life forms started to supply energy for themselves through photosynthesis. Organisms adapted to the environment and created DNA and RNA for themselves to live. They also reacted to different elements in the air allowing them to create energy, -
(2.2 BYA) Earths Appearence
Earth possibly appeared the same as it would t The environment had finished changing and everyhting became quite constant, so the earth became constant too, leaving it as it is today. -
(2 BYA) Oxygen
Oxygen levels reached today's lvels we have in the atmosphere. This happened due to the build up oxygen gas because no living beings were there to use the oxygen up. -
(1.5 BYA) Reproduction
Prokaryotes starting to reproduce.They reacted to the elements in the air, and got used to the different environments they lived in, the organic molecules allowed them to eat and survive, thus leaving them with nothing else to do but advace and start getting the ability to reproduce since everything else was already taken care of. -
(1 BYA) Ozone
The ozone laer was formed, it protected organisms from UV rays. It also allowed organisms to exist on land. This was able to occur due to the build up of gas's creating a protective layer. -
Spallanzani’s Experiment
He did this experiment to show that a vital force wasnt causeing people to get sick. So he boiled meet broth in open flasks, but left one covered and the other uncovered. This showed that microorganisms contaminate the broth. This shows how people get sick and its not just the vital force causing these things. This convinced some people, but others still believed the vital force causes sickness and things to go bad. -
Radiometric Dating
Radiometric dating is used to determine the age of objects such as rocks, based on how much of a radioactive isotope the rock gives off. This allows us to see the age of younger rocks, trees, ect. It is measured in half- lifes. -
Oparin’s hypothesis
The gases in the air might have been able to create single organic compounds. Then over time the compounds could have went through chemical reactions resulted in macromolecules, essential to life. This effected how some people view how life got started. -
Fox
She did extensive research on physical structures that might have caused the first cells. The structures are made from simple organic compounds combinding in a lab. The structures are called microspheres and coacervates. The effects us because it might be a possible way how the first cells were created. -
Lynn Margulis
Proposed that early prokaryotic cells have developed a mutual beneficial relationship. She gave the theory endosymiosis. This says an anaerobic prokaryotic cell engulfed a smaller aerobic prokaryotic. This is possibly created organelles of todays cells. This effects the steps of evolution. -
Thomas Cezh
He discovered properties of RNA. Cech discovered that RNA could itself cut strands of RNA, which showed that life could have started as RNA. He also discoverd ribosomes for RNA. There is contoversy if it was DNA or RNA that was the first genetic material, but RNA has more properties that could sustain life. This changes how people view evolution and the first cells. -
Redi's experiment
In this experiement, two jars were uses, one covered in netting, and the other uncovered. The next day maggots were only found in the uncovered jars because adult maggots could reach the meat to lay eggs. This proved spontaneous generation couldn't happen. Living things had to come from living things. This effected how people view how life is created. -
First Microscopes
Robert Hooke used the light microscopes and discoverd cells. He was the first person to ever observe cells using the microscope. The microscope allow people to study cells and figure out how life started. -
Pasteur’s experiment
He wanted to prove that microorganisms in the air causedthings to become contaminated. So he boiled broth but had a curved flask(the neck was curved). A year passes and nothing happens to the broth. The the neck is removed and the next day the broth is cloudy. He concluded contamination is due to microorganisms in the air. This stopped the argument between spontaneous generation and biogenesis. -
Urey and Miller
Miller took molecules believed to be part of earths early atmosphere and put them into an enclosed system. methane, hydrogen, ammonia, and water were placed into the enclosed environment and Miller had an electric current running through it continuously to simulate lightening storms at the end of the experiment, 15% of the materials were turned into organic compounds, 2% of which was turned into amino acids. Miller showed the world that organic compounds such as amino acids wereneeded forlife
