A Hands On History of Hands at the Grant Museum
By James M Heather, on 9 February 2012
Last week (2 February), I went along for A Hands On History of Hands; a whistlestop tour of the evolution of hands and forelimbs through the ages, stopping to look at some of the interesting examples along the way.
The guides on our tour were zoologist Jack Ashby and palaeontologist Mark Carnall, with a little help from Stan, the resident (replica) skeleton.
The Grant Museum was founded as a teaching collection, and it seems that the current crop of curators are keen to continue this legacy. This is the second night like this that they have run, and for a modern museum it seems to a pretty radical idea; not only can enthusiasts visit and explore the museum after hours, but we are actually given the chance to interact with some of the exhibits.
The evening consisted of several tables of guests listening to the hosts talk us through various elements of hand history, giving each table actual specimens as examples to illustrate their points. This was a thorough talk; there were hand outs and everything.
We spent the first half of the event guessing the species from which different forelimb skeletons may have come, or guessing the purpose of obscurely adapted bones, while being briefed on the theories of limb evolution.
After a short hiatus, during which we roamed the cabinets, we returned to our tables to pass around examples of more esoteric adaptations, and speculated on convergent evolution for similar forelimb functions.
As you might imagine (or perhaps not), the chronological development of forelimbs – from fins to flippers and forelegs to fingers – is an interesting one, with a great deal of variation across both extant species and throughout the fossil record, and this night really highlighted a lot of interesting points for me.
For instance, one such fact is that all tetrapods (vertebrates that either have four limbs, or whose ancestors once did) have derived their forelimb structure from the same basic blueprint.
Furthermore, it is interesting to note that the pentadactyl (five-fingered) forelimb configuration has ended up as the only one seen today (despite there being times in the past when there were competitors), and that any species with fewer has simply lost fingers, while any with more have co-opted bones from elsewhere.
The evening wasn’t just educational from a hands-eye view, but spanned all aspects of evolution; I was particular surprised to find out that, taxonomically speaking, humans count as fish, amphibians and reptiles (as every branch on the tree of life is considered a member of all its parent branches).
This was, by design, a night for education, but more importantly it made sure people had fun. It’s an engaging format, in a wonderful setting, and getting hands-on like this really brings the subject to life.
It takes a special scenario for someone to be able to get away with shouting out, “remember, every table has a bit of platypus on it”, but there in the Grant Museum, it seems right.