Chapter 25 - 19:11 Chapter25: EarlyEarth o...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
19:11 Chapter 25: The History of Life on Earth Early Earth o Earth is about 4.6 billion years (BY) old Radiometric dating of meteorites & moon rocks o Life arose about 3.8 BY ago Chemical traces in rocks 3.8 BY Fossil bacteria in rocks 3.5 BY o No spontaneous generation now, but must have happened then Conditions on Early Earth o Atmosphere C02; CH4; NH3; H2S; H2O No free oxygen o Abundant energy to drive reactions Frequent storms with much lightening Frequent volcanic eruptions Frequent meteor impacts UV light form the sun Life on Earth arose as a result of physical chemical processes.   is a  scientific theory Life is so complex that is must have been created by a supernatural  being.   not a scientific theory (can be tested, observed, evidence) Testable hypotheses explaining the origin of life o 1. Abiotic synthesis of small organic molecules o 2. Joining these molecules into polymers o 3. Packaging these molecules into “protobionts” o 4. The origin of self-replicating molecules Miller & Urey Experiments
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
o Figure 4.2 Alternative Hypotheses o 1. First organic compounds may have been synthesized near hydrothermal 
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern