BIOL 1202 Chapter 25

4 Pages
Unlock Document

Louisiana State University
Biological Sciences
BIOL 1201

1Bio 1202CHAPTER 25THE HISTORY OF LIFE ON EARTHA time line for planet earthThe earth is very old About 46 billion years old As earth cooled the oceans formedHow did life originateWas it really spontaneous generationSomething from nothingThe building blocks of macromolecules can be formed from nonliving matter if the conditions are rightIn the 1920s and 1930s two researchersJohn Burdon Sanderson JBS Haldane in EnglandAleksandr I Oparin a Russian biochemistIndependently hypothesized that the atmosphere of the primitive Earth was probably very different from todays Early atmosphere had little or no oxygenrich in hydrogen methane other hydrocarbons and ammonia Most of these can come from volcanic sourcesSanderson and Oparin suggested that the organic compounds in the first organisms could have been formed by the interaction of sunlight UV radiation and the heat from volcanoes or lightning with the chemicals in the atmosphere of the primitive Earth This process of chemical evolution is called prebiotic evolutionEvolution before life existedThe hypothesis of abiotic formation of organic molecules was tested in 1953 in the laboratory of Stanley Miller and Harold Urey see fig 252A variety of organic compounds were created
More Less

Related notes for BIOL 1201

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.