Do not evolve by hunger

2002/11/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Eboluzioa

Two billion years ago, cyanobacteria were the most abundant creatures in the earth's oceans. They were the first to carry out photosynthesis and, according to theories, this is the cause of which today we have an atmosphere full of oxygen.

At the same time the first eukaryotic algae appeared, but for a billion years they did not evolve much. A group of paleontologists and geochemists from Harvard University have worked on the study of the sediments of then and have published a new theory on the lack of evolution.

According to them, the main reason why eukaryotic algae do not evolve during such a long period would be hunger. Many of the metals present in the water, due to the recent appearance of oxygen in the atmosphere, were precipitated and accumulated in the sediments. This caused the water in the oceans to be reduced very little in minerals, which made that lack, far from promoting evolution, stop.

When the atmosphere was filled with oxygen, a billion years later, food increased again in the oceans. Algae had to wait until then to evolve.