horizontal gene transfer Intelligent Design Origin Of Life

New origin of life thesis: Last Universal Common Ancestor (LUCA) wasn’t actually a single cell

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Or not exactly. Charles Marshall, in Integrative Biology at UC Berkeley:

From the Big Bang to the emergence of humans… we’re asking the age-old question: what is the origin of life? While this question has fascinated humans for centuries, recent breakthroughs have been made that bear remarkable implications. Join us for this special Science at Cal Lecture celebrating the UC Museum of Paleontology’s 100th year anniversary and featuring the Director of the Museum, Professor Charles Marshall. We will learn about the last universal common ancestor (LUCA), the unexpected similarities between prebiotic and human innovation, and the central role that energy and information have played in transforming the planet over the last 4 billion years, leading right up to the present climate crisis. (April 2, 2021)

Marshall favors horizontal gene transfer as a key method of early development because ancestor–descendant evolution is a “very slow” (42:25) evolutionary process. HGT among multiple independent lineages, by contrast, allows a “vast exchange of information,” thus sharing innovations and leading to faster development.

Okay. And in the midst of all that, Dawkins’s Selfish Gene got lost in a crowd somewhere and was never heard from again.

A lot of this thinking revolves around the white smoker, a form of hydrothermal vent:

In 1993, before alkaline vents were actually discovered, geochemist Michael Russell from Nasa’s Jet Propulsion Laboratory (JPL) in California, US, suggested a mechanism by which life could have started at such vents.1 His ideas, updated in 2003,2 suggest life came from harnessing the energy gradients that exist when alkaline vent water mixes with more acidic seawater (the early oceans were thought to contain more carbon dioxide than now).

This mirrors the way that cells harness energy. Cells maintain a proton gradient by pumping protons across a membrane to create a charge differential from inside to outside. Known as the proton-motive force, this can be equated to a difference of about 3 pH units. It’s effectively a mechanism to store potential energy and this can then be harnessed when protons are allowed to pass through the membrane to phosphorylate adenosine diphosphate (ADP), making ATP.

Russell’s theory suggests that pores in the hydrothermal vent chimneys provided templates for cells, with the same 3 pH unit difference across the thin mineral walls of the interconnected vent micropores that separate the vent and sea water. This energy, along with catalytic iron nickel sulfide minerals, allowed the reduction of carbon dioxide and production of organic molecules, then self-replicating molecules, and eventually true cells with their own membranes.

Chemical gardens

Chemist Laura Barge, also a research scientist at JPL, is testing this theory using chemical gardens – an experiment you might have carried out at school. Looking at chemical gardens ‘you think its life, but it’s definitely not’, says Barge, who specialises in self-organising chemical systems. The classical chemical garden is formed by adding metal salts to a reactive sodium silicate solution. The metal and silicate anions precipitate to form a gelatinous colloidal semi-permeable membrane enclosing the metal salt. This sets up a concentration gradient which provides the impetus for the growth of hollow plant-like columns.

Rachael Brazil, “Hydrothermal vents and the origins of life” at Chemistry World (April 16, 2017)

No origin of life theory is seriously plausible when you look at all the facts. But this one at least allows us to show you chemical gardens and white smokers. Here:

and

See also: Researchers search for the “last bacterial common ancestor” (LBCA) in a world of horizontal gene transfer. One senses that the reconstruction will be subject to considerable revision. It’s not entirely clear what “ancestry” means in a world of rampant horizontal gene transfer.

3 Replies to “New origin of life thesis: Last Universal Common Ancestor (LUCA) wasn’t actually a single cell

  1. 1
    Fasteddious says:

    One wonders whether James Tour will attend this event?
    The brief description does not talk much about the actual initial origin of life, presumably because nothing is known about that. Rather it mentions LUCA, which would come after the origin.
    The blurb says, “recent breakthroughs have been made that bear remarkable implications”. Would those be the biomolecular advances that make abiogenesis less and less likely every year or so?
    The mention of how life has changed the world over 4 billion years also is not part of the origin of life. I suppose the “origin of life” could spread out to include “the ongoing evolution of life”, but that is not what “origin of life” usually means.
    Of course there is also the requisite fawning mention of “climate change”.
    Then the “horizontal gene transfer” buzzword is mentioned as one mode of evolution, without asking where those genes actually originated. Some sort of shell game here: seeing things move around looks impressive but makes one forget about where they came from.

  2. 2
    polistra says:

    Seems like an awful lot of precise detail (pH gradients and so on) about an event that might have happened in the past. If it happened at all, it happened just once and can’t be experimentally verified, so the detail doesn’t matter.

  3. 3
    martin_r says:

    Darwinian clowns… if horizontal gene transfer is not a designed thing, then i dont know… for Darwinian clowns everything is so simple… data exchange, sure, a simple thing…. perhaps in Darwinian fantasy world…

    I suggest a great article
    “Do cell use passwords. Do they encrypt information?”
    https://www.biorxiv.org/content/10.1101/432120v1.full

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