Comments on: The Origin of Life on Earth: New Research

By: Owlmirror

Owlmirror — Sun, 15 Jun 2008 01:36:40 +0000

Random layperson thought:I’ve seen the hypothesis that replicators came first. I’ve also seen the hypothesis that metabolism came first (in Robert Shapiro’s June 2007 SciAm article).It occurred to me to wonder, though, if it couldn’t have been both simultaneously: Replicators forming in a particular set (or sets) of chemical and energy environments; metabolisms forming in different sets of chemical and energy environments…And then the replicators infect the metabolisms.Wacky hijinks ensue, which eventually result in cellular replicators.Anyway, I thought it was an idea worth throwing out there to be chewed upon.

By: Tom Buckner

Tom Buckner — Sat, 14 Jun 2008 23:04:15 +0000

Papilio wrote: “In fact, one of the problems to be addressed is the question of whether new life originating in an isolated habitat (underground, for example, as some theories suggest) would have exhausted available chemicals quite quickly, leading to extinction of these first replicators.”Well, one way to deal with the problem of replicators exhausting nutrients is to suppose that this problem does not appear wherever there is what you might call a “sterilizing barrier.” Take for example the deep-sea hydrothermal vents (“smokers”) where superheated water emerges, filled with nutrients. Organisms depend on the smoker, but because the water is so hot as it comes out, no organism can follow the nutrients to the source and exhaust them. The sterilizing barrier in a smoker is the line between livable temperatures (generally below 100°C) and temperatures in which no replicator is known to be able to live (water leaves the vents at as much as 400°C). So perhaps the first replicators spread like wildfire and then all starved, except around vents.

By: Papilio

Papilio — Sat, 14 Jun 2008 16:16:25 +0000

When I said underground, I meant in a puddle (the slow seep of nutrients underground vs the static nutrients in a puddle, is what I was trying to refer to)

By: Papilio

Papilio — Sat, 14 Jun 2008 16:13:15 +0000

Life began in fits and starts, and our problem with finding abiogenesis is one of the philosophical definition of life, not a fault of science.The point is that the first replicators, whatever they were, must have spread rapidly over the entirety of the available habitat (even if it wasn’t the primordial soup of some of the older theories). I imagine it a bit like a wildfire sweeping across the globe, then merely smouldering as most of the available resource is used up – although this may not be an appropriate picture. In fact, one of the problems to be addressed is the question of whether new life originating in an isolated habitat (underground, for example, as some theories suggest) would have exhausted available chemicals quite quickly, leading to extinction of these first replicators.

By: Mike Haubrich, FCD

Mike Haubrich, FCD — Fri, 13 Jun 2008 23:59:38 +0000

This is what’s bugging me about abiogenesis. I think that “eveolutionists” are too quick to say that abiogeneis is not evolution. I don’t see how they can be separated, considering that the definition of life is not fixed.I heard on “Science Friday” one day a few weeks ago that someone said definitively and without question that there was a single abiogenesis event. Even as we read through the article on the viability of e. coli which live on citrates at The Loom, we can’t define what a species is when it comes to a bacterium, how can we possibly state that there was a “first cell?”The beginning of life had to be nebulous, as are species. Sure, DNA and RNA are common to all life, but as the precursors to cellular life evolved from crystalline or nanobacterial form (or whatever) to live, as phospholipids survived to form membranes they would have been spread through a planet covered by 140 million square miles of water I find it hard to conceive that life only started once and evolution began at that point.Life began in fits and starts, and our problem with finding abiogenesis is one of the philosophical definition of life, not a fault of science.

By: J-Dog

J-Dog — Fri, 13 Jun 2008 14:52:47 +0000

Excellent! Thanks for updating me on the latest in this area.