Animals may have existed on earth for hundreds of millions of years before they first appear in the fossil record, according to new research from NUI Galway, just published in the journal, Palaeogeography, Palaeoclimatology, Palaeoecology.
The international study, led by scientists from the School of Natural Sciences at NUI Galway, has shed light on a significant question which perplexed Charles Darwin over a century and a half ago. In his masterpiece, Origin of Species, Darwin had great difficulty in explaining the apparently sudden appearance of many different types of complex animals around half a billion years ago. This observation was based on evidence from the fossil record, but did not fit with his proposal that animals had slowly and gradually evolved from much simpler ancestors over a very long period of time. Darwin could only suggest that, for reasons then unclear to him, the earliest record of animal life on Earth was not represented in the fossil record. This conundrum would later be dubbed ‘Darwin’s dilemma’.