FIU - BSC 2011 - Class Notes - Week 1

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Schools > Florida International University > Biology > BSC 2011 > FIU - BSC 2011 - Class Notes - Week 1

School: Florida International University

Department: Biology

Course: general biology II

Professor: Dr. Ligia-Collado-Vides

Term: Spring 2018

Tags: Biology

Name: BSC2011 lecture notes week 1

Description: Notes on the origin of life

Uploaded: 01/12/2018

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General Bio II – BSC 2011 Lecture Notes Origin of Life  Earth formation as a hot mass of molten rock about 4.5 billion years ago  Cooling of planet, formation of chemically rich oceans formed from water
condensation  Chemically rich waters became rich enough to allow life
to grow  Origin of life is the result of chemical processes
happening in the right conditions  Photosynthesis helped create oxygen  Archaea were the first life forms  Photosynthetic organisms had a large impact on the planet  Increased diversity and complexity Radiometric dating How do we know how old things are on earth?  Elements have radiometric isotopes that can be used to test how much
radiation there is.  Isotopes are different forms of the same elements  Elements are converted from one form to another through radioactive decay  Radioactive decay occurs at a constant rate  The half life of an element is the amount of time it takes
for one half of a sample to decay. Questions  Describe original conditions of the planet and how it eventually got to the
point that life would arise?  What were the first chemical processes and compounds that gave rise to life?  How do you estimate how old rocks or fossils are what kind of samples do you
use? Other beliefs  Panspermia  The hypothesis that life exists throughout the universe. Life may
have infected earth from some other planet, distributed by space
dust, meteoroids, asteroids, comets, etc.  Few geochemists agree on exact compositions of early atmosphere Experiments  Miller & Urey experiment < read up on it  Found within a week that methane gas converted into other gas

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