The Red Notebook

The newly relocated Friends of Charles Darwin website is riddled with junk DNA.

During the migration exercise from the old domain, I had to convert an awful lot of program code and data. Much of this I managed to automate, but I still ended up having to make a lot of changes by hand. Entire chunks of code were removed, others were inserted. I tried to rationalise and simplify wherever possible.

The result is, quite frankly, a bit of a mess. Yes, the new site seems to work reasonably OK, but the programs behind it contain literally dozens of snippets of code which I’m pretty sure are redundant. There are conditional statements whose conditions can never be met, declared variables which are never used, functions which are never called, and entire scripts which are never run. Or at least I think there are. It’s sometimes difficult to tell whether it’s safe to remove a piece of code, so I tended to err on the side of caution and leave the stuff in: code which is never run can’t do much harm—inefficient and messy though it is.

To be honest, I take a perverse pleasure in the Friends of Charles Darwin’s website containing so much junk code. It seems rather appropriate.

Not much sign of intelligent design around here!

An Irish letterbox

Man still bears in his bodily frame the indelible stamp of his lowly origin.

Charles Darwin
Descent of Man, 1871

And, in Ireland, some letterboxes still bear the indelible stamp (no pun intended) of their British origin.

I was in Ireland last weekend for a family reunion. My partner Jen‘s family, that is. While I was there, I finally remembered to take a photograph of one of their old letterboxes. This one bore the indelible stamp E VII R (Edward VII Rex): a vestige from the early Twentieth Century, when Britain, in the form of Queen Victoria’s son, still ruled over Ireland.

It must irritate many proud Irish republicans that symbols of British rule remain on such prominent public display. But cast iron letterboxes don’t come cheap, and they’re pretty useful things. It was probably too much trouble to replace them just for the sake of getting rid of a British king’s monogram. Instead, the Irish very sensibly painted their pillarboxes green and got on with far more important matters, such as rebuilding their country.

If the Irish were starting their postal service from scratch, none of their letterboxes would bear any such imperial anomalies. The fact that they do tells us something about the country’s history. They tell us that things were different in the past; things have changed.

Similarly, the fact that organisms bear anomalies, such leg bones in whales, appendices in humans, and junk DNA in just about any living creature you care to mention, tells us something about the species’ histories. It tells us that species weren’t designed from scratch. It provides vital evidence that things were different in the past; things have changed; species have evolved.

Long live long-lived anomalies!

See also: Can Red Lions Evolve?

Woody

I spent some time reading up about woodpeckers yesterday morning. There is a great spotted woodpecker which visits the bird feeder in our garden most days. Never ones to avoid clichés, we have nicknamed him Woody. On Friday, I managed to get this photograph of him.

Woodpeckers’ toes are a familiar example of an evolutionary adaptation. Instead of the usual (in birds, at least) three toes pointing forward and one toe back, most woodpeckers have two toes pointing forward and two back. This adaptation makes it easier for them to cling to tree trunks.

Yesterday, I learnt that the scientific adjective to describe this toes-in-pairs phenomenon is zygodactyl. Apparently, several different lineages of birds (including parrots and treecreepers) have independently evolved zygodactyl toes for clinging to tree trunks—demonstrating that Nature isn’t afraid of reinventing the wheel.

Then I remembered that Darwin had written about woodpeckers in Origin of Species:

As we sometimes see individuals of a species following habits widely different from those both of their own species and of the other species of the same genus, we might expect, on my theory, that such individuals would occasionally have given rise to new species, having anomalous habits, and with their structure either slightly or considerably modified from that of their proper type. And such instances do occur in nature. Can a more striking instance of adaptation be given than that of a woodpecker for climbing trees and for seizing insects in the chinks of the bark? Yet in North America there are woodpeckers which feed largely on fruit, and others with elongated wings which chase insects on the wing; and on the plains of La Plata, where not a tree grows, there is a woodpecker, which in every essential part of its organisation, even in its colouring, in the harsh tone of its voice, and undulatory flight, told me plainly of its close blood-relationship to our common species; yet it is a woodpecker which never climbs a tree!

As usual, Darwin hits the nail on the head: although evolution through Natural Selection provides organisms with adaptations ideal for certain environments, so might a benevolent creator. But to see an animal, such as a woodpecker, with adaptations better suited for one environment, living in a very different environment is the best sort of proof that something has changed (for which, read evolved). A few paragraphs later, Darwin continues:

He who believes that each being has been created as we now see it, must occasionally have felt surprise when he has met with an animal having habits and structure not at all in agreement. What can be plainer than that the webbed feet of ducks and geese are formed for swimming; yet there are upland geese with webbed feet which rarely or never go near the water…

He who believes in separate and innumerable acts of creation will say, that in these cases it has pleased the Creator to cause a being of one type to take the place of one of another type; but this seems to me only restating the fact in dignified language. He who believes in the struggle for existence and in the principle of natural selection, will acknowledge that every organic being is constantly endeavouring to increase in numbers; and that if any one being vary ever so little, either in habits or structure, and thus gain an advantage over some other inhabitant of the country, it will seize on the place of that inhabitant, however different it may be from its own place.

No matter how well Nature might hone certain species to certain environments, it can only work with the material (species) already available to it—so species’ ancestral heritages often show through in their current designs. Stephen Jay Gould referred to this phenomenon as the Panda’s Thumb, but I like to think of it as Nature’s Kludges.

See also: Can Red Lions Evolve?