the importance of deep time

I suscribe to the wonderful website, SciTechDaily – it’s an excellent way of keeping up with the science headlines. Recently an article on ‘deep time’ caught my eye, & I thought I’d mention it here because the concept of deep time came up (implicitly) in my post on Earth’s birthday.

‘Deep time’ is basically the idea that the Earth is very very old. And the universe, even older. This is something that’s really hard to visualise, & probably for that reason many people find it quite hard to get their heads around. (If you stretched out your arms, & the distance from finger-tip to finger-tip represented the 4.6 billion years of Earth’s existence, then the part of that occupied by ourselves would be the finest possible shaving off a fingernail. Which is a rather humbling perspective from which to view ourselves.)

Anyway, the article I’ve just read is a book review by geologist Richard Fortey, who’s written some of my favourite books (among them Trilobite! and Life: an unauthorised biography). He points out that our concept of deep time owes a great deal to the work of Victorian geologists such as James Hutton & Charles Lyell. What these men had to say about the age of the Earth, and the processes that shaped it (& continue to shape it) effectively revolutionised the way people saw the Earth & its inhabitants. For example, Lyell emphasised that study of the present-day processes such as erosion, sedimentation and glaciation, would permit the accurate interpretation of all those rocks that record the passage of geological time. Many of the rock strata with which Lyell was familiar contained fossils, & scientists such as William Buckland opened peoples’ eyes to the possibility that those fossils gave a window into the rich tapestry of prehistoric life.

And of course, all of this geological upheaval had a considerable effect on the thinking of young Charles Darwin, who made notable contributions to geological science in his own right. Not least because it provided him with time – the time necessary for his proposed model of evolution to have its effect, enabling natural selection to generate the wonderful diversity of living things that populate this ancient planet.

[P.S. Note to purists – yes, I know about the significance of genetic drift as a mechanism for evolutionary change – but Darwin didn’t!]

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