1. Miller-Urey Experiment Chemistry → Biology

2. What do you think is the link between chemistry and biology? Chemistry: Study of chemicals Biology Study of life If life can only come from life, how did life arise?

3. Is your theory/idea good science? How can it be tested?

4. Many scientists, like Charles Darwin, hypothesized that life could have come from something “non living” in very early years of Earth’s life. Unfortunately, it could only stay an idea. At that time, his idea could not be tested. Not much was known for certain about the early Earth, and even if it was, the technology at the time could not recreate the environment of early Earth. Recreating early Earth would be the only way to really test his hypothesis in a valid way.

5. Eventually, technology caught up to our ideas, and we could finally test this hypothesis, making it testable and therefore a valid scientific theory.

6. Miller-Urey Experiment In 1952, Stanley Miller and Harold Urey researched heavily the types of chemicals found in the early stages of Earth’s life. After trying to recreate the conditions of Earth at that time, Miller and Urey made an artificial “Primordial Soup” Primordial soup: the place where scientists suggest all life began from the combination of different elements and molecules in the early years of Earth’s existence (about 4 billion years ago)

7. Primordial Soup The “Primordial Soup” was basically a giant mixture of random existing elements and compounds At this time (4 billion years ago) there was no real atmosphere or anything to protect the elements Some broke down, while others combined to become stronger and better able to withstand the environment This lead to more and more complex compounds, molecules, and eventually the proteins and molecules that make up all living things. More on this later...

8. The Experiment 1. Water (H 2 O), methane (CH 4 ), hydrogen (H 2 ), and ammonia (NH 3 ) were sealed inside a flask, which was connected to another flask ½ full of water a. These chemicals are known to have existed on Earth 4 billion years ago 2. Since the Earth was VERY hot back then, the water in the separate flask was heated and the evaporated water was able to drift into the chemical-filled flask 3. Electrical sparks were added occasionally to recreate lightning (remember, no atmosphere = crazy conditions!) 4. Then the evaporated water was cooled back down to condense and drain into a sterile collecting container

9. The Experiment cont. After one day of continuous action, the chemical solution turned pink After a week, glycine, α - and β -alanine were found in the mixture (AMINO ACIDS WERE NOT THERE BEFORE, PEOPLE.) Amino acids are the building blocks to proteins, WHICH MAKE UP LIFE This proved that early elements were able to combine to form totally new ones After Miller’s death in 2007, sealed vials of the solution were examined only to find over 20 amino acids present

10. https://www.youtube.com /watch?v=NNijmxsKGbc