Talk to the Hand

 

 

(Picture from here.) 

I hurt my hand this week.

It’s a long and sordid story involving using a winch to raise a 200+ pound wood lathe and then letting go at an inopportune moment. The crank whizzed around and caught me at the base of the thumb.

 

That’s the short version. The long version resembles the song Sick Note.

 

The result caused me a day or so where my right hand was essentially useless. Nothing makes a limb more important than the inability to use it and it got me to thinking: where did that hand come from?

 

Never one to miss an opportunity, I started trying to figure this out.

 

We are mammals.

 

Mammals got their start three hundred million years ago. But that’s not so critical to this discussion. What I’m interested in is what mammals were like back towards the end of the Cretaceous, the stem creatures that radiated out when the dinosaurs died out: the Cenozoic Era.

 

The first part of the Cenozoic is the Paleogene. During this period the primates and rodents first evolved. Anyone who’s ever seen a mouse must have noticed their tiny hands. Since primates also have hands, hands must have predated them both. Natural selection works on what it has. A trait that is common between two related groups is likely to have originated before they split. We have a primate hand with an opposable thumb. Rodents do not. But we are not the only mammal with such a thumb. So do opossums and koalas. Likely, they originated their own plan.

 

Regardless, prior to primates, there were tree shrew like creatures that had four fingers and a thumb. They inherited that from much more primitive ancestors. If you look at lizards or even amphibians, you see that same single upper arm, proceeding to two forearm bones, a cluster of wrist bones, followed by the finger bone pattern. The muscles of the forearm power those fingers. This is the pattern land dwelling tetrapods started with.

 

Primates inherited that and took to the trees.

 

Size matters. A mouse climbing up a tree doesn’t need a strong grasp. But a much heavier monkey does. Monkey hands are strong. Strong enough to swing from branch to branch. Strong enough to drop a story or two and catch themselves on a branch and keep swinging. I mean we’re not talking twisting phone books apart (heh. As if there were still phone books.) strong, but much, much stronger than a mouse. Here is a video of a gibbon swinging through the trees. Check it out starting about 1:11.

 

As I stated before, hands are powered by muscles in the forearm that reach tendons down into the fingers. There are some muscles in the palm of the hand surrounding the thumb but most finger strength resides uphill.

 

The Old World Monkeys and the New World Monkeys split when the new world was colonized by old world relatives., about forty million years ago. There’s a lot of discussion how this happened since the continents were already separated. A land bridge might have been involved. Or rafts. Regardless, the OWM were the ones that were left behind. The tailless apes, the Hominoidea separated out about 25 million years ago and the Hominidae, the Great Apes, split off from the Hominoidea about 14 million years ago.

 

By this time were talking some quite large apes, multiple tens of kilograms. Gorillas are commonly over a hundred kilograms.

 

The orangutans split off from the Hominidae leaving the Homininae: what would become gorillas, chimps, and humans. The gorillas split off, leaving the Hominini. The chimps split off and left is as the Hominina.

 

If anybody was concerned we weren’t self-involved enough, I submit the above Hom* sequence, all of which are human centric. When I was in graduate school, we had a continuous gripe about how human anatomy and non-human anatomy. Consider the anterior vena cava and the superior vena cava. Both drain the head end of the body. They are exactly the same structure but in one case the animal is standing up and in the other the animal is on all fours. My old anatomy professor said we should just visualize the human on its hands and knees. All animals can fit in that same box and we can use the same terms.

 

Anyway. By the time genus Homo comes around, the human hand is pretty much conserved. In fact, one of the interesting things about Lucy’s clan was not only that she was standing erect, her hands were pretty human, too.

 

So, now we know the heritage of the human hand, what changed for us?

 

There’s some evidence that human hands are more primitive than chimp hands and my have more in common with gorillas. Both gorillas and humans have pursued a terrestrial lifestyle while chimps are more arboreal. This means that our hands conserve more traits of the last common ancestor between humans and chimps. That said, observing the comparative photographs above, show significant differences between gorillas, chimps and humans. Human thumbs have more mobility than either gorillas or chimps. It’s easy for a human to touch the thumb to each finger easily and with some strength.

 

My suspicion, however, is the anatomical differences are deeper than the apparent musculature and bone. For one thing, our hands have been used alongside tools for nearly three million years. The use of tools has had an influence on the physical structure of our hands in some ways. More importantly, it has changed the way our brains use our hands. No other animal on earth uses tools as extensively as we do. This is a case of synergistic selection. We have a selection for better use of tools which requires a better brain. That better brain sees new uses for such tools, which then, selects for better brains to use those new tools. A virtuous positive feedback loop.

Which brings me back to my injury. Look at the human hand on the left. The winch crank struck the bone at the base of the thumb. Yet, the pain that made me think I’d broken something happened on the opposite side of the hand. Right where the carpals connect to the ulna.

 

It turns out there’s a cartilaginous pad in that little corner between the carpals and the ulna. It serves as a cushion when the hand is moved coplanar with the arm as opposed to when the hand rotates. The doc said this little pad is what was injured. That usually occurs when there is an abrupt and violent movement of the hand to compress that pad. Which must have happened when the winch crank struck the other side.

 

I’ve been unable to find the evolutionary history of that little pad but I suspect it goes back a long, long way.

 

Consideration of Works Past: Room for One More

 

(Picture from here.)

 

I will pretty much watch anything with Cary Grant in it.

 

There are a lot of reasons for this. He has a charm and grace that is always worth watching. He speaks well. Moves beautifully. Most of all, he has a grace in front of the camera that is often lacking.

 

By this, I mean he knows when to take the light of the camera and when to lend it away.

 

The camera loves Grant. He is perfectly capable of pulling in all the light to himself. Yet, he gives that away to his co-actors when required. No one working with Grant gives the least impression they are fighting for the spotlight. He shares it.

 

This makes him as good a co-star as star. You can see that in such films as in Charade or Notorious.

 

Or Room for One More.

 

I saw this film when I was quite young—I couldn’t have been more than ten or eleven. It came out in 1952. Like a lot of films from that period, events outside the frame of the film are not acknowledged but still have a lot of influence. Things like World War II, for example. That is not alluded to in the film but that post-war affluence and giddiness are on display.

 

The film is not perfect in any way. It’s a simple film. George “Poppy” Rose (Grant) and Anna Rose (Betsy Drake) have three children. They had four but lost one—this is referenced a couple of times in the film but the circumstances are never discussed. Anna is part of a church group touring a home for children. The woman running the home states she has no issue finding adoptees for the infants but a terrible time finding homes for the older children. Anna is the kind of person that takes in any stray in the neighborhood and is prevailed upon to take in a troubled teen girl named Jane.

 

Poppy is against it but eventually accepts her in the house. Later, a second child, a polio victim named Jimmy-John. Both children are difficult at first but are won over fairly predictably by Anna, Poppy, and their original children.

 

The film goes forward showing how the foster children become part of the family and how the family is stronger for it. The film is Betsy Drake’s much more than Grant’s and Grant happily moves out of the light and lets her have it. Grant is clearly the stronger presence but he makes sure Drake gets every inch of camera space she needs.

 

One quick aside: from 1916 onward, there was at least one polio epidemic somewhere in the US every summer. In the epidemic of 1949 over 42,000 cases were reported. Polio was a big deal all through the forties, fifties, and sixties. I recall standing in a long line that stretched around the block to get stuck. Every one of the kids was there with at least one parent or parent-equivalent. It was a big, big deal. Every one of us was no more than two degrees of separation from a kid that had had polio. Often, that kid had been crippled by it. When the vaccine came, the country scrambled for it.

 

Watching this, watching Jimmy-John walk with leg braces, I couldn’t help but contrast that with today.

 

*sigh*

 

Anyway, the film is not great. It presents lost kids as a problem and presents a fairly Pollyanna solution. It suggests that this problem, and by extension many problems, can be solved by just stepping up. Christian virtues aren’t mentioned directly but there are oblique inferences that this would be the Christian thing to do.  Harder problems are either not mentioned or papered over.

 

Yet, it works.

 

I’ve been re-reading Parzival lately—which I do on occasion. I’m going to paraphraser Joseph Campbell here. Paraphrasing Wolfram von Eschenbach is a lost causer. (See The Western Quest lectures. Specifically, The Forest Adventure.)

 

In that story, Parzival fails the adventure of healing the Grail King with a compassionate question. He vows to attempt the adventure again even though he is told that this is impossible: the opportunity only comes but once. He is castigated for his failure, told that he is a curse upon the land and is cursed. He decides he hates God: he has served God and God has not been loyal. He goes into the wilderness and is five years in deprivation and loneliness, failing over and over again. He is bitter towards God.

 

At one point, it is Good Friday and he comes upon a little charade of penance by a noble family. The family has left their nice castle and taken a day of penance, walking in the snow and such, with their little dogs and with servants accompanying them with food. The lord berates Parzival for being in armor on this day.  Parzival doesn’t know what day it is. He doesn’t know what year it is. He thinks, they love whom I hate and takes his leave. But, he thinks about this little family acting out this shallow penance and it works on him. It softens him. It makes him ready to confess his sins and at least discuss the idea.

 

I read this section and I didn’t understand it. Why would this purely symbolic, substanceless act move him?

 

As I was watching Room for One More, I started to get it. RFOM is a purely symbolic, substanceless film—it represents the issue but never actually grapples directly with it. But, by acting in the purely symbolic realm, it allows us to infer and grapple with those hard truths on our own. It leaves us that choice.

 

This in no way diminishes the need for the hard look at difficult problems with barely tractable solutions. Too often we have decided the world is good and neglected the hard truth that often that good world is not good for everyone.

 

That said, I wonder if that modern turn towards hardness, pulling that difficult material up close and personal, has cost us something. When you have something shoved in your face, you must react. There is no distance to look at the idea critically. No time to reflect. A person might accept or reject it but that acceptance or rejection might be reflexive. If you call someone an idiot for not wearing a mask, they might reflexively spit on you.

 

A gentle reminder, such as RFOM, allows this reflection. It gives one the opportunity to engage something other than that reflexive, limbic response.

 

Of course, it also allows the opportunity to discard the message of the work with a smug feeling of satisfaction: I watched this movie and agreed and therefore I need not consider it further.

 

Still, I think there’s a place for this approach. One of my heroes in SF is Clifford D. Simak. He excelled at this gentle reproach or encouragement. He didn’t say, you must be your better self or else! More, he said, wouldn’t it be nice to be your better self?

 

And you find yourself agreeing: yes. It would.