Month: September 2022

"MUTATION is a natural process that changes a DNA sequence. And it is more common than you may think. As a cell copies its DNA before dividing, a "typo" occurs every 100,000 or so nucleotides. That's about 120,000 typos each time one of our cells divides." Add to the horizontal gene transfer and you have a sloshing bucket of genes. https://lnkd.in/d9VF6RH View in LinkedIn

HORIZONTAL GENE TRANSFER. "The origin of bacterial genes in eukaryotes. In addition to gene duplication, horizontal gene transfer events have played a major role in the emergence of the eukaryotic cell, as is evident by the significant amount of genes that clearly are of bacterial origin that reside on eukaryotic genomes." https://lnkd.in/ewbMda5 View in LinkedIn

FRAGMENT FROM NATURE this weekend features some articles that discuss the freaky improbability of evolution. It is simply one of biology’s burrs under the skin. A very big one. Skeptics have had a field day on the topic, but the irksome fact remains that we can observe evolution on our timescales today both in microorganisms like yeast and bacteria and also in creatures like birds. It may be a burr, but its existence is irrefutable. View in LinkedIn

THE GREAT PROFESSOR FRED HOYLE. “A junkyard contains all the bits and pieces of a Boeing 747, dismembered and in disarray. A whirlwind happens to blow through the yard. What is the chance that after its passage a fully assembled 747, ready to fly, will be found standing there? So small as to be negligible, even if a tornado were to blow through enough junkyards to fill the whole Universe.” https://lnkd.in/d5RUEK2 View in LinkedIn

LAUGHINGLY IMPROBABLE. "The combinatorial stringing together of all of the steps between LECA and Macropus rufus (the red kangaroo), Trichomonas vaginalis, or Mozart is, indeed, laughably improbable. Surely, if life’s tape was rewound, none of these would recur." (LECA = Last eukaryotic common ancestor). https://lnkd.in/d6GwkCt View in LinkedIn

FREAK ACCIDENT. "Forty years ago, Jacques Monod published his seminal work, Chance and Necessity (Monod, 1971). Monod's bleak perspective, that the origin of life was a freak accident, and that we are almost certainly alone in an empty universe, was opposed by Christian de Duve, who has argued that life is a "cosmic imperative", and as such will arise throughout the universe." https://lnkd.in/dtE8XQK View in LinkedIn

CONTINGENT. "Steven Jay Gould advocated the contingency of evolution: wind back the clock, and life will evolve again along radically different lines." https://lnkd.in/dtE8XQK View in LinkedIn

CONVERGENT. "Simon Conway Morris argues that convergence is the stronger force – the principles of engineering dictate that the same, or similar, solutions will emerge repeatedly." https://lnkd.in/dtE8XQK View in LinkedIn

HIGHLY UNLIKELY EVENT. "A sudden transition in a system from an inanimate state to the living state—defined on the basis of present day living organisms—would constitute a highly unlikely event hardly predictable from physical laws." https://lnkd.in/dS2NY3q View in LinkedIn

NUCLEIC ACID PROBABILITY. "The random formation of biopolymeric components, for instance nucleic acids, from their building blocks. The probability of a single sequence of 50 nucleotides among all possibilities corresponds to 1/4(50) ≈ 0.8×10(-30) meaning that the exploration of the complete set of sequences over 1 billion years would require the synthesis of more than 4 ×10(13) different sequences every second." https://lnkd.in/dS2NY3q View in LinkedIn