Well there's a new article "May Atheism Succeed Demographically" that has invoked another variant of social Darwinism, yet again.

Certainly there are many situations in which one might utilize the concept of evolution, in describing a variety of scenarios.  In general, the point may be to demonstrate that something changes over time, usually with the perspective that it may be improving or adapting to some situation, although such a directionality is not a requirement. 

Specifically with biology, the concept relates to natural selection where particular traits are "filtered" by the environment, resulting in more adaptive populations having a greater likelihood of continuing.  Natural selection has no directionality or purpose.  It is simply a description of what results when subjected to the "filter" of the environment.

Yet, in this article we are treated to all manner of non-scientific mumbo-jumbo under the auspices that it is somehow representative of anything to do with biology.

It's not only that religious people tend (on average) to have far "more" children than their non-religious peers
- it's also about that ominous fact that we do not know about a single
non-religious group or population that managed to retain at least the
reproductive replacement level for just a century.

Note, the quantum leap into natural selection, without the slightest inclination to provide evidence as to why a religious belief should be heritable.  In fact, it should be clear that since there is no genetic component to such a religious belief and can be readily acquired or discarded at any point in an individual's life, this is simply an assertion that is [in its kindest interpretation];  rubbish.

In addition, it is also clear that there is an agenda being advanced.

Charles Darwin was a learned theologian and rightfully concluded in his
"Descent of Man" that to be true, evolutionary theory must be able to
explain the emergence of religious beliefs and cultures, too.
http://www.scilogs.com/nature-of-faith/about-the-blog/

Yet, despite this claim, it isn't actually true.  What Darwin actually said was:

For the moral
qualities are advanced, either directly or indirectly, much more through
the effects of habit, the reasoning powers, instruction, religion, etc.,
than through natural selection; though to this latter agency may be safely
attributed the social instincts, which afforded the basis for the
development of the moral sense.
http://www.gutenberg.org/cache/epub/2300/pg2300.html

Welcome to more pseudoscientific nonsense.