New consideration of conditions favorable for the emergence of life. A University of Washington study published in Communications Earth & Environmental reports that shallow “soda lakes” in western Canada may be suitable for the emergence of life. Life may have originated in one of these early Earth lakes about 4 billion years ago. Under the right conditions, complex biological molecules can form spontaneously, but this requires very high phosphate concentrations. Phosphates form the “backbone” of RNA and DNA and are also important components of cell membranes. The concentrations of phosphate required to form biomolecules are hundreds of millions of times higher than levels typically found in rivers, lakes, and oceans. Soda lakes can solve this “phosphate problem” about the origin of life. Soda lakes get their name from the large amounts of dissolved sodium and carbonate in them. This is the result of a reaction between water and the underlying volcanic rock. High levels of dissolved phosphate are also common in soda lakes.
Using a combination of chemical models and laboratory experiments, the researchers showed that natural phenomena can cause phosphate concentrations in these lakes to be up to a million times higher than in other bodies of water. They may also be candidates for life on other planets. “The planet’s surface is mostly made up of volcanic rock, so if water existed, it is possible that similar water chemical reactions would have occurred not only on early Earth, but also on early Mars and early Venus. “There is a strong sense of gender,” said lead author Sebastian Haas. The highest levels of natural phosphate are found at Last Chance Lake in interior British Columbia, Canada. In most lakes, dissolved phosphates quickly combine with calcium, but in Last Chance Lake, calcium combines with carbonates and magnesium to form dolomite. When calcium becomes dolomite and no longer remains in the water, phosphate binding disappears and the concentration increases.