Two recent studies have revealed that that the movement rate of plates carrying the Earth's crust may not be constant over time, which provides a new explanation for the patterns observed in the speed of evolution and has implications for the interpretation of climate models.
Researchers led by Professor Peter Cawood, from the University of St. Andrews, UK, examined several measures of continental movement and geologic processes from a number of previous studies.
Cawood suggested that this stability may have been due to the gradual cooling of the earth's crust over time and he said that before 1.7 billion years ago, the Earth's crust would have been substantially hotter, meaning that continental plate movement may have been governed by different rules to those that operate today.