Yes, it’s Origin of Life at the movies tonight, so fetch popcorn. And who better to talk about it than our favourite chemist James Tour?:
A conversation between Dr. James Tour and Socrates in the City host Eric Metaxas on the topic “How Did Life Come into Being?” Dr. Tour is presently the T. T. and W. F. Chao Professor of Chemistry, Professor of Computer Science, and Professor of Materials Science and NanoEngineering at Rice University. He is widely regarded as among the leading nano-scientists in the world.
This event took place at the River Oaks Country Club in Houston, Texas in October 2022.
At Cat’s Board, we learn of at least 14 major hurdles in the way of origin of life:
- Natural selection: There was no selection on early earth. In the living world, complex molecular machines are pre-programmed to make the building blocks of life, precisely as needed.
- Time: Some chemical reactions are so unspecific that getting the right one by unguided means resorting to time leads to huge numbers of odds.
- Getting pure materials: Evidently, what chemists do in the lab, namely using pure reagents, was not what happened on the early earth. Impure contamination in the pool of chemicals was the state of affairs.
- Getting free Gibbs energy: Spontaneous prebiotic reactions would have to “invent” ways to recruit Gibbs free energy from its environment so as to reduce its own entropy.
- Activation and repetitive processes: Monomers need to be activated in order for polymerization and catenation to make amino acid strands, and genes, to be possible.
- Information: Specified complex information, digital data, stored in genes through the language of the genetic code, dictates and directs the making of irreducibly complex molecular machines.
- Polymerization: How did prebiotic polycondensation of amino acids and nucleotides in heterogeneous aqueous solutions or in interfaces with water-based media occur without the aid of biological catalysts?
- Eigens paradox: is one of the most intractable puzzles in the study of the origins of life. It is thought that the error threshold concept described above limits the size of self-replicating molecules to perhaps a few hundred digits, yet almost all life on earth requires much longer molecules to encode their genetic information.
- Muller’s rachet: The theory of Muller’s Ratchet predicts that small asexual populations are doomed to accumulate ever-increasing deleterious mutation loads as a consequence of the magnified power of genetic drift and mutation that accompanies small population size.
- Protected environments: If these chemical reactions had happened in places being exposed to UV radiation, no deal. If it was too cold, or too hot, too acidic, or too alkaline, in the wrong atmospheric conditions, no deal.
- The right sequence of reactions: In metabolic pathways in the cell, enzymes must be lined up in the right sequence. How did spontaneous events organize such a state of affairs?
- Getting an organized system out of chaos: How did a prebiotic soup come to be organized into systems capable of emergent processes such as growth, self-propagation, information processing, and adaptive evolution?
- Irreducible complexity: The cell is an irreducible, minimal entity of life. The individual parts by themselves bear no function unless integrated into a higher-order system.
- Homeostasis: The control of metabolism is a fundamental requirement for all life, with perturbations of metabolic homeostasis underpinning numerous disease-associated pathologies.
That’s the condensed version. Much more at the site.