dude, pull my finger

Here's a perfect illustration of the abysmal quality of science journalism, as well as the more general tendency of journalists to cannibalise each others' work to occasionally ridiculous effect: the story that's been all over various news sources this week about the bloke who miraculously grew back a finger after having it sprinkled with some magic dust (aka "extra-cellular matrix").

Those of a naturally healthy sceptical bent would have reacted first with fascination and secondly with various questions, such as: a) how much finger did he lose in the first place? b) is this sort of recovery unprecedented? c) how do we know it was the "magic dust" that did the trick? The answers given in the articles vary a bit but can be summarised as being, respectively: a) ooh, lots b) ooh, yes, I expect so c) well, it's magic, isn't it? The lack of anything resembling detail in any of the stories, and the fact that the original incident seems to have happened way back in 2005, would lead you to smell a big fat sweaty nicotine-stained journalistic rat at that point.

Needless to say it turns out that the truth is somewhat more mundane, in that the actual answers are: a) the whole finger-tip, essentially, but not all of the nail and little or no bone b) not at all c) we don't, in fact it seems highly unlikely that it was.

Bad Science has some more detail, including some amusing backtracking by the news sources when it became clear we weren't about to be able to lop the odd limb off during a bit of careless gardening, sprinkle some magic pixie dust on the gushing stump and have it spontaneously regenerate chameleon stylee. Here's the BBC's effort.

The only morsel of actual interest in all of this is the revelation that doctors have discovered that it's better, in situations like this, to leave the stump alone as much as possible for it to heal, rather than do what they used to do, which was to apply a skin graft over the exposed stump. It turns out that this inhibits the regrowth of the dermal and epidermal layers (presumably by "confusing" them in some way) and results in the wound healing less well and invisibly than just leaving it to sort itself out. That's an actual science story, right there.