How do we know how life began? Origin of Life How do we know how life began?

Voyager’s Golden Record https://www.youtube.com/watch?v=OVe72eMY_pk The Voyager Golden Records are phonograph records which were included aboard both Voyager spacecraft, which were launched in 1977. They contain sounds and images selected to portray the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form, or for future humans, who may find them. The Voyager spacecraft are not heading toward any particular star, but Voyager 1 will be within 1.6 light-years of the star Gliese 445, currently in the constellation Camelopardalis, in about 40,000 years.[1] As the probes are extremely small compared to the vastness of interstellar space, the probability of a space-faring civilization encountering them is very small, especially since the probes will eventually stop emitting electromagnetic radiation meant for communication.

Hypothesis 1: Life delivered through comets Late heavy bombardment of comets 4 billion years ago Panspermia: hypothesis that life on Earth originated from material delivered by a comet, either in the form of amino acids or as hardy bacteria Living organisms “seeded” on earth as “passengers” aboard comets Avoids the problem of life originating on earth, transfers problem of origin of life to another place Asteroid: A relatively small, inactive body, composed of rock, carbon or metal, which is orbiting the Sun.  Comet: A relatively small, sometimes active object, which is composed of dirt and ices. Comets are characterised by dust and gas tails when in proximity to the Sun. Far from the Sun it is difficult to distinguish an asteroid from a comet.   Meteoroid: A small particle from an asteroid or comet orbiting the Sun

Hypothesis 2: Spontaneous formation Age of earth: about 4.6 billion years ago Conditions of pre-biotic earth High temperature High levels of carbon dioxide and other green house gases  produce globally high temperatures Lightning Reducing atmosphere (no O2) Hydrogen and hydrogen-containing gases: methane, ammonia, hydrogen sulfide Carbon dioxide, nitrogen, water vapor Formed from volcanic activity

Hypothesis 2: Spontaneous formation Simulate high energy sources Electric spark (simulate lightning) Heating water (simulate high temperature) Simulate reducing atmosphere Water vapor, hydrogen, methane, ammonia (HAM) Products: mixture of amino acids Amino acids = building blocks of life, what makes proteins

From amino acids to cells?

Cells research https://www.cellsalive.com/ (Click on interactive cell models) Watch a video about cells https://www.youtube.com/watch?v=1Z9pqST72is https://askabiologist.asu.edu/cell-parts