National Geographic on the evidence for evolution

Following my recent medical disappointments, I have been pondering, as you do in such circumstances, the big questions. Like: What Do I Really Believe? And it turns out that one of the biggest things I believe in is evolution, as the best explanation for why we humans are the sort of creatures we are, altruistic and selfish, affectionate and murderously aggressive, doomed to die, and so on. I was raised by Church of England atheists, and that is what I still am. The older I get the more this is so.

But what is the evidence for the truth of evolution, as opposed to the rival god-did-it explanations which evolution is slowly but surely replacing?

Was Darwin Wrong? asks a recent National Geographic cover. Inside, in very big capitals, the answer: NO. (Thank you Steve Stewart-Williams.) I opened up the article, to learn what I hoped would be more about all this evidence.

No one observation of the natural world would be enough to convert a convinced god-ist, because after all, god can do anything he pleases. Atheism is hard to prove with one knock-out punch. But evolution wins, for me, overwhelmingly, on points. Point after point after point, each point being made perfect sense of by the idea of natural selection of chance variations, and each point meaning that any god is going to have to have been the kind of god who, for no very obvious reason, wanted all creatures without exception to look exactly as if they had all evolved. Simply, evolution makes sense to me, while god, especially the idea of God that Christians and Muslims proclaim, makes, to me, no sense at all. It’s the range and volume of evidence that is so convincing.

Two of the many points made in the National Geographic article made particular sense to me. It’s not that I’d never thought before about such things, just that this time around, they both hit home with particular force.

Point one:

All vertebrate animals have backbones. Among vertebrates, birds have feathers, whereas reptiles have scales. Mammals have fur and mammary glands, not feathers or scales. Among mammals, some have pouches in which they nurse their tiny young. Among these species, the marsupials, some have huge rear legs and strong tails by which they go hopping across miles of arid outback; we call them kangaroos. Bring in modern microscopic and molecular evidence, and you can trace the similarities still further back. All plants and fungi, as well as animals, have nuclei within their cells. All living organisms contain DNA and RNA (except some viruses with RNA only), two related forms of information-coding molecules.

Such a pattern of tiered resemblances — groups of similar species nested within broader groupings, and all descending from a single source — isn’t naturally present among other collections of items. You won’t find anything equivalent if you try to categorize rocks, or musical instruments, or jewelry. Why not? Because rock types and styles of jewelry don’t reflect unbroken descent from common ancestors. Biological diversity does. …

Point two:

Vestigial characteristics are still another form of morphological evidence, illuminating to contemplate because they show that the living world is full of small, tolerable imperfections. Why do male mammals (including human males) have nipples? Why do some snakes (notably boa constrictors) carry the rudiments of a pelvis and tiny legs buried inside their sleek profiles? Why do certain species of flightless beetle have wings, sealed beneath wing covers that never open? Darwin raised all these questions, and answered them, in The Origin of Species. Vestigial structures stand as remnants of the evolutionary history of a lineage.

As I tried to explain in this conversation with Patrick Crozier, evolution performs, for me, many of the functions of a religion, in that it gives the best answers we humans have to the “big questions”, like: Where did we come from? And: Why does life feel the way it does for us? It even makes sense of things which we personally reproach ourselves for feeling, like an extreme and “irrational” fear of irrationally hostile strangers.

What I do not feel, now or ever, is any need to believe anything to be true that I do not in fact believe to be true. In that sense, evolution is not my “faith”, if that’s what faith is. Doubting Thomas, in the Bible (here comes my Church of England upbringing), says to Jesus: “Lord I believe. Help thou mine unbelief.” I simply believe what I believe, and doubt whatever I doubt. I believe in evolution, not just as true but as very helpfully and very illuminatingly true, and I do not doubt it.

When checking the links in the above, I discovered that National Geographic doesn’t want me to read that article again. It seems I have gone beyond my limit. I hope that if you want to read it, you’ll be luckier.

Colourful turtles and tortoises

Here:

Top row left to right: eastern box turtle, pancake tortoise and Bell’s hingeback tortoise.
Middle row left to right: radiated tortoise, Florida box turtle and Burmese star tortoise.
Bottom row left to right: spotted turtle, Bourret’s box turtle and European pond turtle.

For me, the bottom row is a bit of an anti-climax, but the top two rows are amazing. Blog and learn. Although, what I have not yet learned is why it is useful for turtles and tortoises to look like this. It surely can’t be camouflage, can it? Mimicry of something very scary to predators? But who are the predators of turtles and tortoises? Big bastard birds presumably. But what do I know? In the meantime: Wow.

Found, inevitably, on Twitter, via the Twitter feed, equally inevitably, of Steve Stewart-Williams.

Patrick posted our conversation about Steve Stewart-Williams and evolution ( and I’m glad he did)

I am starting to take exercise by doing exercises, which I have not done since my school days, which put me right off the whole idea. I am being supervised and guided and advised and encouraged by a physiotherapist attached to the Royal Marsden. This morning I attended (virtually) one of his group exercise sessions, and it was a real effort, lasting more than half an hour. Then, after only brief lie-down, I went out on a big shopping expedition, and of course bought too much stuff for me to carry in comfort and am now totally knackered. But, I still owed this blog its daily feed.

Luckily, however, an email from Patrick Crozier has now arrived saying that our latest recorded conversation is now up and listenable to, so here’s my posting here alerting you to that.

Our conversation was based on and revolved around the book by Steve Stewart-Williams entitled The Ape That Understood The Universe, which regular visitors to this blog will know that I like a lot.

Patrick and I have already fixed that the next of our conversations will be about how World War One started, which Patrick knows a lot more about than I do.

Three especially good links to SteveStuWill

As I mentioned earlier in the week, I’ve been catching up with the SteveStuWill Twitter feed. This time, I’ve picked out just three creaturely amusements that particularly entertained me. I could have listed many more, but these are the ones I especially liked. I mean, if I link to lots of them, you might as well just go there and scroll. If I pick only a few, you get only a few, which may be just what you want.

So: Male sea horse giving birth, to a lot of sea foals; a black heron hunts fish by blocking out the sun; and perhaps most remarkable of the lot, the courtship dance of the hooded grebe. Enjoy.

Predator or prey – look at the eyes

I found this here:

Which I guess makes us humans predators. Makes sense. Many surely knew this and predator eyes and prey eyes, but I did not know this.

I further guess that fish are accordingly the ultimate prey.

Otters in Singapore City

The whole world is becoming a giant zoo, curated by humans. Now, for instance, there are otters living in Singapore City:

Singapore’s otter families all have names. Here, the Bishan family crosses a street in the city center.

Start reading this National Geographic article, and you soon encounter a link to another NG piece about how Hundreds of wild parrots are thriving in this Brazilian city.

But back to those otters. As Singaporeans become more affluent and more inclined to welcome the otters into their midst, and less inclined to do things like kill them and eat them, instead treating them as sort of mobile urban sculptures, …:

In 2016, an otter family suddenly ran across the Singapore Marathon route, and Otter Working Group volunteers rushed to warn the runners of the otters’ presence, as well as also position themselves along the route to prevent the animals and runners from colliding.

… the otters themselves are, understandably, becoming less frightened of humans than they used to be. Evolution in action. The adventurous otter families, willing to explore human cities in search of new ecological niches, get selected for, and the more timid ones have a harder time of it.

LATER: It’s happening here also. Otters are making themselves at home in UK cities.

Steve Stewart-Williams on the evolution of the Breton fishing boat

I finished reading The Ape That Understood The Universe about a week ago now, but there is one further bit from this book that I want to scan into this blog, because I think it is my absolute favourite.

At the beginning of the second half of the book devoted to Man, “The Cutural Animal”, SS-W offers six examples of cultural evolution in action. These are: Breton Boats, Conditioned Behavior, Language, Teddy Bears, Businesses, and Science. I have already copied the bits on Teddy Bears, and on Language. Here is the bit about Breton Boats (p. 224):

The first example concerns the fishing boats used by Breton fisherman in the Île de Groix. Where did these boats come from? At first glance, it looks like a no-brainer: If anything’s a product of intelligent design, it’s a boat. On closer inspection, though, it turns out it really is a no-brainer … or at least a partial-brainer, in the sense that human brains played a more modest role in crafting the boats than we normally assume. This possibility was first mooted by the French philosopher Emile-Auguste Chartier (aka Alain), who in 1908, took a Darwinian hatchet to the common sense view. “Every boat,” he observed,

is copied from another boat … Let’s reason as follows in the manner of Darwin. It is clear that a very badly made boat will end up at the bottom after one or two voyages, and thus never be copied … One could then say, with complete rigor, that it is the sea herself who fashions the boats, choosing those which function and destroying the others.

If a boat returns, the boat makers may copy it. If it doesn’t, they definitely won’t. The boats that are most likely to be copied are therefore those that survive the longest. As Daniel Dennett points out, no one needs to know why these particular boats survive. To make a good boat, you don’t need to understand what makes a boat good; you only need to be able to copy another boat. How do you know you’re copying a good boat? Well, you don’t need to know, because the sea automatically culls the not-good ones from the boat population. Meanwhile, any especially good boats get copied at a faster rate. Over time, this process of culling and copying fashions more and more seaworthy boats.

Now maybe each and every step in the gradual evolution of the boat was a product of intelligent design: of a thousand forgotten boat makers figuring out a thousand different ways to make their boats more sea-worthy. But maybe not. Maybe many steps along the path were simply fortuitous accidents, which were automatically preserved and propagated. To the extent that this is so, the design evident in Breton boats comes from blind, mindless selection, rather than the machinations of intelligent minds.

Language and Teddy Bears are a bit off the beaten tracks I like to beat. But with this discussion of the design of a quite big physical object, in this case a boat, SS-W’s core agenda, and one of my obsessions over the years and decades ever since I was a failed architecture student, overlap in a very big way. As I said at the end of the language posting linked to above, I have long been thinking along the same lines as SS-W, about “mindless” design. And as I said at the end of another recent posting here, about Facadism, Keeping Up Appearances and so on, it is my earnest hope that I will, by and by, be able to pull such thoughts together in a bigger piece for Samizdata.

The Modern Movement in Architecture was, when it started out, shot through with the idea that you should not “mindlessly” copy an established design, even if it worked well, unless you knew why it worked well. Wrong.

Equally and oppositely, the first lot of Architectural Modernists said that you should turn your back on “mindless tradition” and design anew, from “first principles”. Very dangerous, as a design technique. Something like this is sometimes necessary, provided you choose good “first principles”, but it is never without extreme hazard. Architectural Modernism only worked well, and in a country like Britain has only started to work well, when Modernism itself became a tradition, embodying the experience of what worked and what works, and what did not work and what does not work.

Steve Stewart-Williams on the evolution of language

Today, right near the end of The Ape That Understood The Universe (pp. 275-276), I had another What He Said moment:

… Earlier I mentioned that humans have an innate capacity to learn language, but that the specific languages we learn evolve culturally to mesh with our language-hungry brains. There may be a twist in the plot, however. It’s possible that our languages themselves helped to wire a language-learning instinct into the human genome. Here’s what might have happened. It all began with the cultural evolution of a rudimentary proto-language: a system of grunts and gestures not too far removed from what we see today in wild chimps. We didn’t have a dedicated language faculty at that time, so we acquired this proto-language via general learning mechanisms. (This is presumably what captive apes do when they learn to communicate with signs.) The proto-language wasn’t nearly as useful as our modern ones. But as anyone who’s visited a foreign-speaking country knows, even a little language is better than none. As such, any ancient human who acquired the proto-language more easily, mastered it at a younger age, or used it more adroitly, would have had an advantage over her more linguistically ham-fisted contemporaries. And what an advantage! Language is useful in virtually every sphere of human life: communicating needs and wants, organizing hunts and other cooperative ventures, entertaining mates, conveying useful information to offspring, finding out who to trust and who not to. In these areas and others, better language-users would have had a definite edge. Given the evolutionary importance of these activities, such individuals would plausibly have had more offspring, and their linguistic advantage would have spread through the population. As humans became more verbally adept, this would have triggered the cultural evolution of a more complex proto-language. That in turn would have created a selection pressure for even greater linguistic giftedness, which would have spurred the cultural evolution of an even more complex language – the usual story. In short, the cultural evolution of language resulted in the biological evolution of a language-learning instinct, and vice versa.

If so, this has an interesting implication. We saw earlier that genes for lactose tolerance were a consequence of milk drinking, rather than a cause. The same may be true of language. We tend to assume that genes for language came first, thereby making language possible. It’s equally likely, however, that it’s the other way around: that language came first and then created a selection pressure for genes promoting the rapid acquisition of language. In other words, our gift of the gab may have started with a cultural mutation, rather than a genetic one.

I worked out this notion, that culture creates new evolutionary spaces for genetic evolution to move into, several years ago, but it is good to have it confirmed by SS-W. I presume that this means that, what with culture hurtling towards new evolutionary spaces all the time, that means that genetic evolution is hurtling onwards, faster than ever before.