EDWARD'S LECTURE NOTES:
More notes at http://tanguay.info/learntracker
C O U R S E
Big History: From the Big Bang until Today
Esther Quaedackers, University of Amsterdam
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C O U R S E L E C T U R E Speculations on How Life Emerged on Earth Notes taken on January 3, 2017 by Edward Tanguay |
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how could all of this complex life have emerged from far more simple chemicals
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very little hard data
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a lot of room for speculation
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what we have is speculation based on some empirical evidence
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current hypotheses for the emergence of life
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in any case
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it happened a long time ago
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in a place unknown
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1. panspermia hypothesis
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it might have arrived from outside the earth
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e.g. in meteorites
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2. spontaneous generation
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it might have happened here on the planet
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agrobacterium tumefaciens
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infect plants with cancer
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e.g. the bacterium is regulating the tree, instead of the tree doing what it wants to do for itself, it serves the bacterium
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the genetic material of the bacterium can change what a tree does
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therefore the genetics must be very similar, otherwise this would not work
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it points to similar biochemistry
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points to a common ancestor
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when you eat an banana
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the building blocks of a banana are similar to that of humans
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if you try to eat a rock, you can't digest it
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tracing a common ancestor
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tree of line
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points to a common ancestor about 3.5 billion years ago
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stomatolites
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tiny bacterial sitting on rocks
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necessities for life
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replication
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metabolism
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RNA
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between DNA and proteins
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like the Swiss Army knife of the body
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stands for Ribonucleic acid, which is a polymeric molecule essential in various biological roles in coding, decoding, regulation, and expression of genes.
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RNA and DNA are nucleic acids, and, along with proteins and carbohydrates, constitute the four major macromolecules essential for all known forms of life
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RNA differs from DNA in three ways
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RNA is single-stranded instead of double-stranded
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RNA contains ribose, DNA contains deoxyribose
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the complementary base to adenine in DNA is thymine, whereas in RNA, it is uracil
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you find these three conditions in liquid water and clay