Almost entirely, in fact. Jeffrey Tomkins writes “Marketing Myostatin Inhibitors with Fake Science,” about nutritional supplements being marketed to reduce the activity of a protein called Myostatin (literally “muscle stop”) with the intent of increasing muscle mass. According to Tomkins, one claim made is that myostatin is somehow “vestigial”:
Because of the benefits of lowering myostatin levels for bodybuilders, one of the sales pitches claims that the myostatin genetic pathway is a vestigial evolutionary remnant—a sort of Darwinian leftover in humans that we need to correct. However, as can be clearly seen from the studies in animals, bodies need myostatin to regulate cell growth. In fact, humans who eat a healthy low-calorie and low-fat diet, along with exercising regularly, already have low myostatin levels compared to those with unhealthy lifestlyes.
Curiously, Tomkins doesn’t actually cite anyone making the claim. I have managed to find one case, however:
Myostatin is a protein produced by a specific gene sequence in the DNA of nearly every vertebrate animal. Controlling myostatin is the holy grail of extreme muscle growth. Why would your body need myostatin? It has been theorized that this vestigial control over muscle gains was needed to prevent an organism from being overly muscled and thus fall more easily to predation either because they would have been too bulky to speed away or because they just looked more delicious. So through Darwinian selection, having little or no myostatin has become exceedingly rare among animals and humans. Nevertheless those rare survivors live normal, happy, albeit well-muscled lives. As examples, the Belgian Blue bull and the Piedmontese breeds are born without the gene to produce myostatin. From a health standpoint, these animals are not at all adversely affected by the absence of myostatin.
We often accuse creationists of not understanding what the word “vestigial” means – it doesn’t necessarily mean that the organ in question has no function at all, being a little more nuanced than that – it’s clear that whoever wrote that paragraph has an even poorer understanding of the relevant concepts. Not only is the classification of myostatin as vestigial here absurd, but they or their source apparently had to speculate that you need myostatin “to prevent an organism from being overly muscled and thus fall more easily to predation either because they would have been too bulky to speed away or because they just looked more delicious.” In fact, myostatin deficient (and therefore overly bulky) cattle breeds like the Piedmontese and Belgian Blue are more likely to need caesarean sections and have other problems reproducing without human help. A gene can make you as muscled and strong as you like, but if it stops you breeding then it’s really not going to catch on.
As for Tomkins own article, while I could quibble on language choice the only major problem I have is with the second sentence of his closing paragraph:
The evolutionary spin written into myostatin inhibitor advertisements ignores good science while appealing to an imaginary evolutionary past [as I said, there’s a lot to quibble about]—all in order to sell product. Myostatin and its complex functional role in the cell is evidence of divine bioengineering, not evolution.
Tomkins explains in his article what these functional roles are, but the concluding claim that it’s all “evidence of [God], not evolution” comes completely out of left field. It could be that as he mentioned earlier in his article that myostatin has a “purpose” he thinks that this is enough for it to have to have been designed – a modification of his usual “if it’s complex it’s designed” line. Alternatively he could have been intending to take a swipe at the whole concept of vestigiality but ran out of time or space, choosing instead to quickly rap up with this stock line. We may never know for sure.