“Extraordinary claims require extraordinary evidence” was a phrase made popular by Carl Sagan who reworded Laplace's principle, which says that “the weight of evidence for an extraordinary claim must be proportioned to its strangeness” (Gillispie et al., 1999). [refer to this article]
Now, here's an extraordinary claim: all life as we know it has descended from an initial microscopic organism (just comprised of one cell) through random variation and environmental selection (I prefer 'environmental' selection as a term to 'natural selection'. The word 'natural' smuggles in a higher level belief that is not warranted).
This is an extraordinary claim, and it becomes more extraordinary the more we learn about the cell, microbiological processes, protein 'machines' and the information that runs the cell. It is a claim beyond extraordinary and flies against all we know about formal systems.
The basic extraordinary claim
The basic extraordinary claim is that more specialised organisms arise from random errors in complex, finely tuned living close coupled interlocking systems of systems that are preserved, propagated and accumulated against environmental pressure to result in completely novel systems, body forms and functions.
This is first asserted, then assumed. It is never demonstrated, let alone 'proven'.
Typically it is merely propagandised by illustrations of creatures reconstructed from fossils tendentiously arranged in a series.
At a more sophisticated level it is 'proven' by gene sequencing and other microbiological comparisons. But this is vulnerable to the fallacy of affirming the consequent. A first-year science undergrad error. Much more needs to be proved than taking the observations of organisms and reversing them up a steep slope into a stupendously extraordinary hypothesis.
So, Mr evolutionist. Present your extraordinary evidence.
....long period of silence follows.
