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Articles by Chris Basel
The limited value of wet–dry cycles to produce large peptides prebiotically
The equilibrating reactions to form peptides through condensation are thermodynamically unfavourable in water. However, wet–dry cycle experiments by origin of life researchers have increased the yield and length of peptides, using carefully designed, but prebiotically implausible, conditions. High pH values had to be used; unrealistically high amino acid (AA) concentrations, and environmental catalysts which degrade AAs were avoided.
Relative proportion of prebiotic amino acids: part 3—experiments using reduced gas mixtures
Evolutionists believe the prebiotic atmosphere would have consisted primarily of CO2/N2 or CO/N2, along with H2O. Key Miller-type experiments reported in the literature on mixtures of highly oxidized gases using spark discharge to mimic the energetic effects of lightning produced only trace amounts of amino acids (AAs), primarily glycine. Even when high concentrations of the reducing gases CH4 or H2 were added, usually ~99.5% of the proteinogenic AAs produced were glycine and alanine.
Relative proportion of prebiotic amino acids: part 2—models to form highly reduced atmospheres
Most Miller-type experiments have used highly reduced gas mixtures no longer considered to reflect the composition of a prebiotic atmosphere. Speculative models have been reviewed for evolutionary mechanisms to produce favourable reducing atmospheres. These involved enormous theoretical impactors able to deliver gases such as CH4, NH3, CO, and H2, and/or also a high iron content able to convert all, or most, terrestrial water into reducing H2.
Relative proportion of prebiotic amino acids: part 1—experiments using reduced gas mixtures
The primary source of prebiotic amino acids (AAs) is often claimed to have been high energy splitting of atmospheric gases. A review of key Miller-type experiments using reducing mixtures like CH4/NH3/H2/H2O showed that other compounds able to react with AAs were usually not reported. Only a very few proteinogenic AAs were obtained in most of the experiments reviewed. Typically, ~99.5% of the proteinogenic AA yields consisted of only glycine and alanine.
Amyloid world—the impossible requirement for identical prebiotic peptides in high concentration
High concentrations of identical or very similar peptides are required by origin of life models like the amyloid world hypothesis. The most likely peptide candidates would be as short as possible and use the most abundant amino acids (AAs). Assuming that two glycine and two alanine AA could have been used, the smallest suitable peptides would likely be octapeptides. However, octapeptides would have had a steady-state concentration ≈ 10–44 M in water at ca.
Non-existence of error correction in plausible prebiotic amyloids
Nanda et al. have claimed that equilibrating networks of peptides can ‘correct errors’ by decreasing the proportion of sidechain products and D-amino acid configuration. Their system involved highly concentrated peptides having sequences able to template the reactions by forming β-sheets. The three amino acids used would not have been present prebiotically.
Life did not originate from amyloids and ATP
Recent proposals for how life might have begun from ordinary, simple chemicals on the early earth do not withstand scientific scrutiny. One proposal is the amyloid world hypothesis, coupled with the idea that ATP could form prebiotically. Both ideas have little hard scientific evidence. ATP does not form readily in or near hydrothermal vents.
Enantiomeric amplification of amino acids: part 10-extraction of homochiral crystals accompanied by catalytic racemization
For abiogenesis to be possible, a natural process must separate proteinogenic L-amino acid enantiomers from racemic mixtures. It was shown that laboratory methods that separate L- and D-amino acid enantiomers based on differential solubility are impossible under unguided natural conditions. Preferential enrichment was used to separate these enantiomers in the solution phase. Crystallization-Induced Asymmetric Transformation was used to separate enantiomers in the solid phase.
Enantiomeric amplification of amino acids: part 9-enantiomeric separation via crystallization
For some amino acids (AAs), DL racemic crystals are more soluble than pure D or L crystals, and vice versa for other AAs. Experiments to amplify small initial excesses of L enantiomers are critiqued here for lacking realism under natural conditions: Excessively high concentrations of pure AAs would have been required. Solution temperature would have to be kept fixed as water slowly evaporated.
Contamination meteorite samples with terrestrial amino acids
This article is from Journal of Creation 38(2):7–11, August 2024 Meteorites, the source of most extraterrestrial material, are believed to have provided a wide variety of proteinogenic amino acids (AA) according to Origin of Life researchers. The chemicals identified from fragments are listed, but, until recently, little or no effort has been dedicated to quantifying how much was due to terrestrial contamination, although contamination is considered to be inevitable. In 2021, Glavin et al.
Increasing L amino acid proportions: part 8
This article is from Journal of Creation 38(1):54–59, April 2024 In this series, we have been evaluating various proposals from the Origin of Life (OoL) community on how a small enantiomeric excess (e.e.) of D- or L-amino acid (AA) could have been amplified naturally. In other words, a mixture already contained an excess of one enantiomer, and a method was proposed on how it might have been locally enriched.
Increasing L amino acid proportions: part 3
This article is from Journal of Creation 37(2):112–120, July 2023 Enhanced chirality using single enantiomer amino acid impurities Most biological amino acids (AAs) form crystals composed of a racemic mixture of the D- and L-enantiomers, but some AAs form conglomerates of individual (S) and (R) crystals from highly concentrated aqueous solutions.
Intelligence After Next: Recommendations for Creating Cross-Agency Enterprise Design Specifications
To achieve mission decision advantage, the Intelligence Community must eliminate structural and cultural barriers to integration. We propose a tailorable framework for the collaborative development of enterprise integration design specifications, ensuring systems and capabilities can seamlessly interoperate across the broader enterprise. In outlining this new approach, we highlight key roles and responsibilities, consider key requirements, and propose a cross-agency governance structure.
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