The calcium of shells came from the bottom of the sea

2004/09/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Eboluzioa

The first animals with shell appeared at the beginning of the Canbric Period. The presence of shells gave them many advantages; many animals developed their shells and, over time, these harsh structures became pioneers of the skeletons, among others. But it is not clear why shells were developed precisely at that time and so fast. And in evolution the shells suddenly appeared, it was not a progressive process.

Now, some American geologists have discovered that at that time the sea had a lot of calcium. This can be one of the causes of the appearance of shells.

According to these geologists, 530 million years ago the amount of calcium increased considerably in the seas. At that time, calcium 'captured' has been measured in the stones and compared to that of 10 million years earlier. Apparently, calcium grew sharply in the sea, probably due to the launch of submarine volcanoes.

The influence of the elements present in the sea in evolution is a very interesting hypothesis for biologists, since several measurable data can help to develop other hypotheses.