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The evolutionary tree of life can be documented with evidence.
The Origin of Life on Earth is another story…
Bacteria Archae- bacteria Animalia Fungi Protista Plantae 4500 4000 3500 3000 2500 2000 500 1500 0 1000 Formation of earth Molten-hot surface of earth becomes cooler Oldest definite fossils of prokaryotes Appearance of oxygen in atmosphere Oldest definite fossils of eukaryotes First multicellular organisms Appearance of animals and land plants Colonization of land by animals Paleozoic Mesozoic Cenozoic Millions of years ago ARCHEAN PRECAMBRIAN PROTEROZOIC
The theory that earth was seeded with primitive life forms from other planets where life actually arose – possibly via a meteor or asteroid from that planet.
This merely puts the origin of life backwards to another earth-like planet. It might be possible for very small, radiation resistant spores to travel around the universe under light pressure or for contamination by space travel to occur.
Coacervate growth and division Collection of aggregated polymers Grow by adding new polymers Form a semi-permeable membrane When they get too big they divide Demonstrates how polymers aggregate and act like membranes
Haldane and Oparin (~1920s) proposed that life arose from nonliving conditions by means of a series of changes (and increasing complexity) in molecular composition as a result of the reducing, high energy environment that existed on early Earth (between 4.6-3.8 bybp (billion years before present)
Such simple molecules might accumulate in shallow seas
Smaller molecules might condense together to form ‘coacervates’ (term by Oparin) to form larger molecules
Clays & RNA might be critically important as catalytic surfaces for the formation of such molecules
Laboratory experiments show that clays, other rock surfaces are excellent ‘nucleating centers’ for formation of complex organic molecules.
Origin of Organic Molecules CH 4 NH 3 H 2 Electrodes discharge sparks (lightning simulation) Water vapor Condensed liquid with complex, organic molecules Condenser Mixture of gases ("primitive atmosphere") Heated water ("ocean") Water
• Jelly fish are mobile organisms. Sea anemones are sessile organisms.
• Single entrance that serves the the cavity that functions of the circulation of respiratory gases and nutrient. These organisms are secondary consumers and posses stinging cells with toxins called nematocysts to disable prey.