First Iceball Earth is back (as a theory), now the volcanic vent as well. Seems to be Origin of Life Week around here.
The biochemist David Deamer proposes that life evolved from a collection of interacting molecules, probably in a pool in the shadow of a volcano.
Deamer (Ucal Santa Cruz)
… thinks that volcanic landmasses similar to those in Iceland today would have made a hospitable birthplace for his proto-cells. Freshwater pools scattered across steamy hydrothermal fields would be subject to regular rounds of heating and cooling. That cycle could have concentrated the necessary ingredients — including both lipids and the building blocks for RNA — and provided the energy needed to stitch those building blocks into biological polymers. Deamer is now trying to re-create these conditions in the lab. His goal is to synthesize RNA and DNA polymers.
Deamer is best known for the “membrane first” theory of the origin of life.
Many scientists study individual steps in the emergence of life, such as how to make RNA. But you argue that life is a system, and it began as a system. Why?
DNA is the center of all life, but it can’t be considered alive even though it has all the information required to make a living thing. DNA cannot reproduce by itself. Put DNA in a test tube with water, and it just slowly breaks into different pieces. So right away, you see the limitation of thinking about single molecules as being alive.
To get a bit of what we call growth, you have to add the subunits of DNA, an enzyme to replicate the DNA, and energy to power the reaction. Now we have molecules that can reproduce themselves if they have certain ingredients. Are they alive yet? The answer is still no, because sooner or later the subunits are used up and reproduction comes to a screeching halt. So how do we get to a system that’s really alive? That’s what we and others are trying to do. The only way we can think of is to put DNA into a membranous compartment. More.
If Deamer is right, that life began a system, we face a number of preliminary questions before we can just continue tinkering, no?
See also: Suzan Mazur interviews an origin of life society president (Deamer)
Origin of life: Iceball Earth is back It’s a horseshoe in the works for the early evolution of life.
Origin of life: Could it all have come together in one very special place? (volcanic vents)
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