Chapter 18, Problem 1TC

Summary Introduction

To explain:

The several hypotheses for evolution of monomers does not negate that the evolution of monomers was the first basic stage of evolution in the origin of life.

Introduction:

The hypothesis includes the prediction based on an observation about occurrence of a phenomenon in life. It does not have a proof or validation for the experimental designing. It does not include verification of the values obtained after the experiment.

Explanation of Solution

The several hypotheses which do not negate the observation that the evolution of the monomers was the first basic stage of evolution in the origin of life include:

1)

Primordial soup hypothesis: This hypothesis included the formation of the metabolites from ammonia, urea and hydrogen in a liquid broth after stimulation from an electric discharge in the broth. It is also called as Oparin-Haldane hypothesis. This hypothesis was confirmed by Miller and Urey.

2)

Iron-sulfur hypothesis: This hypothesis was proposed by Gunter Wachtershauser and explained that the hydrothermal vents contain iron and nickel catalyze the reaction of elements like carbon dioxide, ammonia, and hydrogen sulphide. They derive the process for the formation of polymers from the basic monomer molecules.

3)

Protein first hypothesis: This hypothesis was proposed by Sidney Fox which included the formation of protein polypeptides from the amino acid, due to stimulation from sunlight.

Conclusion

The three hypotheses of primordial soup, iron-sulfur and protein first hypothesis confirmed that the evolution of life includes the formation of polymers from the monomers during evolution. These monomers are the first formed elements without controversy.