Astronomy 1021 Chapter Notes - Chapter 15: Cambrian Explosion, Stromatolite, Chemical Evolution
10 Apr 2014
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15. 1 the nature of life: the physical basis of life on earth is the element carbon, carbon atoms bond to each other and to other atoms. Therefore, the can form long, complex stable chains that are capable of storing and transmitting information. But this is unlikely because silicon chains are harder to assemble and disassemble than carbon and can"t be as long: other speculations: electromagnetic fields and ionized gas. Proteins are the cell"s basic structural molecules or are enzymes that control chemical reactions: genetic information stored in dna is passed along to offspring. They did not reproduce but instead linked together and broke apart at random. Chemical evolution: the chemical process that led to the growth of complex molecules on primitive earth. 540 million years ago, life suddenly branched into a wide variety of complex forms: cambrian explosion: a geologically brief period about 540 million years ago during which fossil evidence indicates earth life became complex and diverse.
