Heterochronic evolution explains novel body shape in a Triassic coelacanth from Switzerland

Heterochronic evolution explains novel body shape in a Triassic coelacanth from Switzerland

Lionel Cavin, Bastien Mennecart, Christian Obrist, Loïc Costeur & Heinz Furrer

Scientific Reports 7, Article number: 13695 (2017)  

doi:10.1038/s41598-017-13796-0

Abstract

A bizarre latimeriid coelacanth fish from the Middle Triassic of Switzerland shows skeletal features deviating from the uniform anatomy of coelacanths. The new form is closely related to a modern-looking coelacanth found in the same locality and differences between both are attributed to heterochronic evolution. Most of the modified osteological structures in the new coelacanth have their developmental origin in the skull/trunk interface region in the embryo. Change in the expression of developmental patterning genes, specifically the Pax1/9 genes, may explain a rapid evolution at the origin of the new coelacanth. This species broadens the morphological disparity range within the lineage of these ‘living fossils’ and exemplifies a case of rapid heterochronic evolution likely trigged by minor changes in gene expression.

Peter Harrison - Why religion is not going away and science will not destroy it

In 1966, just over 50 years ago, the distinguished Canadian-born anthropologist Anthony Wallace confidently predicted the global demise of religion at the hands of an advancing science: ‘belief in supernatural powers is doomed to die out, all over the world, as a result of the increasing adequacy and diffusion of scientific knowledge’. Wallace’s vision was not exceptional. On the contrary, the modern social sciences, which took shape in 19th-century western Europe, took their own recent historical experience of secularisation as a universal model. An assumption lay at the core of the social sciences, either presuming or sometimes predicting that all cultures would eventually converge on something roughly approximating secular, Western, liberal democracy. Then something closer to the opposite happened.

Not only has secularism failed to continue its steady global march but countries as varied as Iran, India, Israel, Algeria and Turkey have either had their secular governments replaced by religious ones, or have seen the rise of influential religious nationalist movements. Secularisation, as predicted by the social sciences, has failed.