A number of researchers feel that such conditions would stifle the ability of life on Earth-like planets to thrive - and that episodes such as this might actually hinder the development of complex (and eventually sentient) multicellular life forms.

Researchers at the University of Toronto and Texas A&M University have published data in Nature magazine which suggests that a belt of open water at the equator may have provided a refuge for animals while the rest of the planet was frozen over. These researchers suggest that the environmental challenge posed by these harsh conditions could explain the burst of evolutionary innovation that followed the Snowball Earth/Proterozoic Era - the so-called "Cambrian explosion".

While the data is of clear relevance to understanding the origin and evolution of life on Earth - and planets similar to Earth - there are also implications for worlds such as Europa that remain encased in a near-perpetual covering of ice - one which apparently breaks open in places for brief periods of time.

Related links

° Equatorial water may have provided means of survival for early life, press release, University of Toronto
° Neoproterozoic 'snowball Earth' simulations with a coupled climate/ice-sheet model, Nature (Abstract - free registration required)
° A Refuge for Life on Snowball Earth, Science, [summary - can be viewed for free once registered. A subscription fee is required for full access.]

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