Empirically equivalent

The following is from Alister McGrath's The Dawkins Delusion? Atheist Fundamentalism and the Denial of the Divine (pp 36-37):

[L]et's consider a statement made by Dawkins in his first work, The Selfish Gene.

[Genes] swarm in huge colonies, safe inside gigantic lumbering robots, sealed off from the outside world, communicating with it by tortuous indirect routes, manipulating it by remote control. They are in you and me; they created us, body and mind; and their preservation is the ultimate rationale for our existence.

We see here a powerful and influential interpretation of a basic scientific concept. But are these strongly interpretative statements themselves actually scientific?

To appreciate the issue, consider the following rewriting of this paragraph by the celebrated Oxford physiologist and systems biologist Denis Noble. What is proven empirical fact is retained; what is interpretative has been changed, this time offering a somewhat different reading of things.

[Genes] are trapped in huge colonies, locked inside highly intelligent beings, moulded by the outside world, communicating with it by complex processes, through which, blindly as if by magic, function emerges. They are in you and me; we are the system that allows their code to be read; and their preservation is totally dependent on the joy that we experience in reproducing ourselves. We are the ultimate rationale for their existence.

Dawkins and Noble see things in completely different ways...They simply cannot both be right. Both smuggle in a series of quite different value judgments and metaphysical statements. Yet their statements are "empirically equivalent." In other words, they both have equally good grounding in observation and experimental evidence. So which is right? Which is more scientific? How could we decide which is to be preferred on scientific grounds? As Noble observes — and Dawkins concurs — "no-one seems to be able to think of an experiment that would detect an empirical difference between them."