This blog is currently on hiatus owing to work commitments. Whilst I still keep an eye on the goings on at RiAus, and contribute to the work of the good folks at eLife, little will be added to this blog for the foreseeable future. Simon Says remains open for business, albeit at a reduced capacity. Thanks for stopping by, and I hope the archive of content found here will prove to be of interest.

Saturday, 17 November 2012

But How Do They Know? | The Evolution Enigma

Badongo, Durrell Wildlife Conservation Trust,
September 2011
Source: me
Earlier this year the genetic sequence of the gorilla was revealed for the first time. It led to a flurry of news articles, flagging new findings that parts of the gorilla genetic sequence are more similar to humans or chimpanzees than those species are to each other — which defies the traditionally accepted order of species evolution — and other tantalizing titbits of information on our handsome cousins. But punctuating these articles was a statement that slipped by without explanation, to be accepted as written and memorized by fact fans everywhere. Thus: the last common ancestor of gorillas and humans lived 10 million years ago.

But this is a big statement.

We frequently read and hear phrases such as “scientists tell us”, followed often by superfluous details of a larger tale. But rarely is an attempt made to explain how such knowledge is acquired. You know the type: “humans and fruit flies are 60% genetically identical” or “sea levels will rise X metres by the year Y.” But how do we know these statements are true? Do we know they are true? If no explanation is given, should we be surprised if many refuse to accept scientific consensus?

This, then, is for everyone who has heard something and sought to know more, who has shouted in frustration: “BUT HOW DO THEY KNOW THAT?”

So: 10 million years?