1. The History of Life…in 1 Lecture
The History of Life…in 1 Lecture! Origins of Life and the Continuation of Evolution
Big Idea 1: The process of Evolution drives the diversity and unity of life

2. Essential Knowledge
1D1: There are several hypotheses about the natural origin of life on Earth, each with supporting evidence.
1D2: Scientific evidence from many different disciplines supports models on the origin of life.

3. Practice!!
In the past, how was the earth different? Come up with 3 things and list them. Then, share with your partner!
How do you know they were different?

4. ‘Organic Soup’ Hypothesis
Early Earth’s atmosphere had inorganic precursors from which organic molecules were made (w/ help of nature and chemical reactions)
May be outdates…Bioessays journal…geothermal vents may have provided the chemical energy to make building blocks.

5. These building blocks (monomers) formed more complex polymers (protein /nucleic acids) in solution or on solids.
Oparin and Haldane, 1920

6. How to Make Cells?
Abiotic synthesis of small organic monomers  Join to make polymers  Packaging in a membrane (protobionts)

7. Protobionts

8. Urey and Miller Experiment, 1950
Hyperlink!
Urey and Miller Experiment, 1950
Notice: No Oxygen and Lots of Free Energy Needed!
Amino acid creation from abiotic chemicals

9. RNA World Hypothesis
Self-replicating RNA were precursors to current life, which is based on DNA, RNA, and proteins.

10. RNA is found in every important biological process…slow evolution time
RNA is found in every important biological process…slow evolution time. DNA evolved bc more stable.
RNA stores genetic information like DNA, and catalyzes chemical reactions like an enzyme protein (ribozymes).

11. Provides support for models on the origin of life.
Geological Evidence
Provides support for models on the origin of life.

12. Early Earth Formed about 4.6 billion years ago
Early earth was too hostile until 3.9 bya

13. Earliest Fossils 3.5 bya, Cyanobacteria

14. Ever wondered why every organism has a common genetic code???
Molecular Evidence
Ever wondered why every organism has a common genetic code???
COMMON ANCESTRY!

15. Time to review…