Scientists have completed an analysis of the head width of more than 1500 species of termites. They have found out that their size isn’t gradually shrinking at a geological timescale.
Termites belong to the cockroach branch and they have split from cockroach group at the end of the Jurassic period which was 150 to 170 million years ago. Scientists suggested that after this split, they got smaller and smaller. According to a new study, published in Proceedings of the Royal Society B, suggests that they got smaller over a 20-million-year period and then their size stabilized.
Evolutionary Genomics Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) scientists claimed that the difference in the results from their research comes from including fossilized species.
Scientists have studied about the evolution of the size of termites. The size is represented by their head width. It has been measured by taxonomists in the last hundred years. Previously scientists have measured the head width as a stable measurement. It was not affected by sample preservation methods.
Modern non-termite cockroaches are larger than modern termite. Scientists first proposed that termites have been getting smaller since the split. The body size of insects is related to the complexity of their society. Smaller insects can fit in a in a smaller space. More individuals can split up their tasks and it will give a chance to workers and soldiers to evolve. Termites are social cockroaches. So, this theory is applicable for them. Though it is not widely tested.
There are over 3000 species of termites. The new study was robust. The study has examined half of the described species. Scientists have tested 1562 living and 76 fossilized species. The oldest species lived around 130 million years ago. The head width of the smallest termite was around 0.5mm. The head width of the largest termite was around 5mm.
The study highlighted the evolution of sociality within social insects.