Scientists of the Institute of Science and Technologies Okinawa found out that termites are not reduced in the process of evolution, as previously thought. This is reported in the article published in the Journal Proceedings of The Royal Society B: BioLogical Sciences.
A popular hypothesis assumed that after his separation from the ancestors of modern cockroaches 150-170 million years ago, termites gradually decreased and continued to do this at the moment. However, a new study revises this point of view and shows that the decrease has passed only during the first 20 million years, after which their size has stabilized.
The size of the termites presented by the width of the head was measured by the systematics over the past hundred years. Since the cockroaches are larger than termites, it was believed that the size of the latter decreases during the evolution after the separation. It was associated with a social lifestyle, since a small body made it possible to fit into the space to more individuals. Accordingly, insects can be divided into castes, such as workers and soldiers, and perform different tasks.
To refute the hypothesis, the researchers analyzed fossil species who lived 100 million years ago, and found that they were already rather small, and the smallest individuals (the width of the head of 0.5 millimeters) there were about 50 million years ago. To compare the ancestor of all modern termites, the head width is estimated in two millimeters.