Early Earth & LifeEarly Earth & Life

Age of the EarthAge of the EarthEarth is 4 – 5 billion years old (using Earth is 4 – 5 billion years old (using radioactive dating and core sampling)radioactive dating and core sampling)

Formation of the planetFormation of the planetCollisions among debris and gases in Collisions among debris and gases in space contributed to the formation of space contributed to the formation of EarthEarth

So what was Early Earth like?So what was Early Earth like?

Oparin’s Theory – early Earth was:Oparin’s Theory – early Earth was:1) hot, volcanic, electrical storms1) hot, volcanic, electrical storms2) lots of gases (DEADLY gases like ammonia, hydrogen, 2) lots of gases (DEADLY gases like ammonia, hydrogen, carbon dioxide & carbon monoxide, methane, etc…) carbon dioxide & carbon monoxide, methane, etc…)

3) water vapor ONLY, no liquid water3) water vapor ONLY, no liquid water 4) no “free” oxygen4) no “free” oxygen Eventually the Earth cooled, liquid water condensed Eventually the Earth cooled, liquid water condensed

forming seas/oceansforming seas/oceans

Miller & Urey experimentsMiller & Urey experiments

• Miller & Urey conducted an experiment to Miller & Urey conducted an experiment to test Oparin’s Theory.test Oparin’s Theory.

• Though they were not able to create life Though they were not able to create life itself, they created the potential for life in itself, they created the potential for life in the form of amino acids (organic the form of amino acids (organic compounds)compounds)

Miller & Urey experimentMiller & Urey experiment

What is the significance of What is the significance of this experiment?this experiment?

• This enormous finding inspired a multitude of further experiments on the origin of life

Different Scientific Theories on the Different Scientific Theories on the Origin of LifeOrigin of Life

1)1) Spontaneous generationSpontaneous generation life from non- life from non-living thingsliving things

2)2) Biogenesis Biogenesis life from living things life from living things

Experiments on Spontaneous Experiments on Spontaneous GenerationGeneration

1) Redi – 2 jars of meat, one covered one 1) Redi – 2 jars of meat, one covered one not covered. The uncovered jar had not covered. The uncovered jar had maggots, the covered jar didn’t have maggots, the covered jar didn’t have maggots.maggots.

Conclusion: life can’t come from non-living Conclusion: life can’t come from non-living things.things.

Redi’s experimentRedi’s experiment

Spallanzani’s ExperimentSpallanzani’s Experiment

2) Spallanzani – boiled broth in 2 flasks, one 2) Spallanzani – boiled broth in 2 flasks, one was sealed, the other was not sealed. The was sealed, the other was not sealed. The unsealed flask became cloudy with unsealed flask became cloudy with bacteria.bacteria.

Conclusion: broth does not produceConclusion: broth does not produceBacteria. Microorganisms in theBacteria. Microorganisms in theAir produce more microorganismsAir produce more microorganismsIn the broth.In the broth.

PasteurPasteur

3) Pasteur – boiled broth3) Pasteur – boiled broth in an unsealed flask in an unsealed flask with a curved neck. with a curved neck. The broth never The broth never became became contaminated.contaminated.

Conclusion: supported Conclusion: supported biogenesis.biogenesis.

Today’s argumentToday’s argument

• Even today, the argument of where life came from is still being debated…….

• http://youtu.be/bqGSW8ufd5w