It's amazing how often I find people using the language of design to describe evolutionary explanations. Consider the following account of how chameleons evolved the ability to change colors [hat tip: Geek Press]:
However, the reason why they first evolved this ability to flash bright colours was previously unclear.
Scientists report in the journal Plos Biology that it was to allow them to signal to other chameleons.
Pay attention to how that's worded. They evolved the ability to allow them to do something rather than to allow them to do something else. It doesn't say that they developed the ability by random chance, and the ones who had it survived or reproduced more because the ability benefited them in survival or reproduction. It says that they evolved it so that they would be able to stand out among other chameleons. This looks like a purpose statement to me.
Consider also this similarly-framed explanation:
Scientists think vertebrae evolved to help our ancient predecessors swim more powerfully by stiffening the body so attached muscles could generate more force.
This is the language of design. It makes sense to speak of something evolving to help the species accomplish something only if there was something that guided the evolutionary process with such a purpose in mind.
Scientists talk like this all the time. So do philosophers. I heard Kwame Anthony Appiah on NPR's Talk of the Nation this afternoon, and he slipped into this kind of design talk when giving an evolutionary example.
We are exquisitely designed by, I believe, evolution, but I don't want to get into that argument, to be very sensitive to other people's responses to our behavior and to other people's interests. Little children, tiny children, will respond to pain in those around them by seeking to comfort them, often before they can barely speak. So we're exquisitely attuned to one another....
People complain that it's not science when theists draw the conclusion that such language actually implies. If design has occurred, then someone has intended some result. Such views won't even get the honor of being recognized as versions of the classic philosophical argument that appears in many introductory philosophy books. If it's a philsophical argument, then it can't be the religious dogma that many so people are so heavily invested in pretending it is, so there's no chance the anti-ID political movement will recognize these arguments for what they are.
But then people who have no interest whatsoever in theistic or design explanations will slip into design talk whenever they're trying to explain how some beneficial characteristic evolved. Despite all the effort trying to resist any true design in nature, design talk keeps appearing in evolutionary explanations. It's as if we're subconsciously inclined to find design in things even if we consciously strive to avoid doing so. Given the premises of naturalism, this kind of talk is hopelessly confused. Since I'm no naturalist, I'm happy to accept that there is indeed something that such design talk refers to -- divine purposes. But I don't think those who accept naturalistic explanations of the universe have the intellectual right to speak this way. You can't just help yourself to design talk in science if design is something fundamentally unscientific and undetectable by science.