New details of beginnings of life on the planet
Recent experiments have revealed that two important components of the beginnings of life, the genetic material and the cell membrane, probably merged thanks to clay. The study of montmorillonite clay has shown that it can considerably speed up the process of forming of membrane sacs filled with water. These bubbles, like primitive cells, can grow and divide in a simple mode.
During previous researches it turned out that clay helps create ribonucleic acid from simpler substances.
Leslie Orgel, senior fellow and research professor from the Salk Institute for Biological Studies in San Diego, California says: "The clay itself is inside of the bubbles. These scientific results are very interesting as they have demonstrated the relation between the mechanism of RNA formation and the mechanism of its enclosure inside of a membrane."
Even though the genesis of genetic material and the cellular construction formation are, as scientists say, hot research spheres, no connection could have been determined between the two phenomena for a rather long period.
The genetic material formation means a lot for the appearance of such phenomena as life, inheritance, mutations and evolution. Membranes are important for the physiology of cells because they protect the cell contents, accumulate chemical substances for reactions and separate important genes from unnecessary ones.
Science has already proved that some components of RNA-similar molecules and membranes may spontaneously form as a result of chemical reactions in space and under conditions that might had existed at the time when there was no life on Earth. However, it is not clear yet how the components managed to combine later.
As for ribonucleic acid, one of the theories solves the problem by pointing at the unusual characteristics of montmorillonite clay. A positive layer forms between the negative layers of montmorillonite clay crystals; the positive layer in its turn intensively accumulates RNA components that make up long chains there.
Scientists decided to find out whether montmorillonite made for formation of bubbles of simple components of fatty acids. It turned out that it did: clay accelerates the process of bubbles formation 100 times. Bubbles that are thus formed contain clay particles, may grow and absorb more and more components of fatty acids.
Researchers have demonstrated as well that clay may contain both RNA and the bubbles at the same time. RNA marked with fluorescent substance was attached to clay; after a reaction, the RNA was inside of bubbles. As a result of the experiment, some kind of protocells was formed. Researchers managed to divide the protocells by carrying them though small holes; they thus divided into smaller bubbles, and the loss of contents was minimal at that.
Researchers admit that bubbles could hardly be divided this way under natural conditions. That is why experts are looking for mixtures of membrane forming molecules that could divide as soon as they reach some definite size.