When the Whales Walked - Dec 23

It so happened that I came across Dougal Dixon’s book, ‘When the Whales Walked’. It is a book for children, with little text but plenty of illustrations, and it talked about evolution. Again, it is a book for children, with little text, but plenty of illustrations, but as it usually happens with Mr. Dixon, the text there could have used some work.

What are the problems of WWW? Firstly, an overly basic reduction of the terms. What is evolution in child-friendly terms? There is a population of fuzzy (or fluffy) woobies, where all look the same. Eventually, a mountain range rises up and splits the wooby population into two. One population eventually ends up living in a savanna, where it evolves longer legs to further and faster cool down in the warm climate, and also to better attract mates with the coloration of their legs. The second population ends up living in a tundra, where it evolves shorter legs to preserve more of its’ body heat, and also tusks or claws designed to scratch out worms and other invertebrates in the harsh and hard tundra soil, upon which it feeds. As enough time passes the two wooby populations change enough so to become two different species instead of a single one, the end.

Sounds simple, right? Team Dixon tried to go one further, by reducing the population by just one. Namely, there is a single new island in the sea, with a single food source – some sort of shrimp. Some sea birds can survive on it, but only those that can eat shrimp. Those who cannot leave or die, with the remnant eventually forming a new species. Straightforward? Yes, but also unrealistic. In real life, there is never a single food source in a new place, such as a new volcanic island in the sea. (To those people in Indonesia who died in the tsunami – our hearts go out to you). There are always several, (even now, with human overfishing and environment pollution), and there are always several bird species on any island. To reduce them to a single one is too much, too absurdedly much.

Secondly, there is the use of the word ‘mutation’. Broadly speaking, ‘mutation’ means ‘transformation’, ‘change’, but due to various modern mass media influences, (especially Marvel and DC comics, movies and TV/online series), these days it is usually associated with a physical change – say, male birds, such as the fowl, sprouting new features, such as tails and head crests, or male elephants keeping their tusks, while the females – not so much. (Female Asian elephants usually lack them). In reality, however, evolutionary changes can mean not only physical changes, but also behavioral ones – i.e., sea otters learning how to use rocks to smash shellfish and sea urchins, Galapagos woodpecker finch using cactus spines to catch grubs, or Homo Erectus, a human ancestor, learning how to utilize fire.

…Okay, true, at least 90% of the WWW book is dedicated to the various animals evolving into new species by acquiring new physical traits – i.e., whales going from the Indohyus, an animal more similar to the modern mouse deer, to the modern species, such as the blue whale. Fair enough, but even that has went somewhat wonky, at least once: when the book talked about crocodile evolution raising a suggestion that once upon a time, (in the Triassic), crocodiles were very different animals and even warm-blooded – unlike today, when they are cold-blooded. This is an interesting topic, so let us elaborate on it.

Firstly, the crocodiles belong to the archosaur family, which also includes pterosaurs, non-avian dinosaurs, and birds. Kudos to WWW for uniqueness by pointedly not mentioning non-avian dinosaurs, BTW – you do not often find this approach in a paleontology book, especially one for the children.

Secondly, modern crocodiles and their cousins are only distantly related to the Mesozoic species that are featured in WWW and similar books. ‘The Complete Guide to Prehistoric Life’, which featured prehistoric animals that were chosen to appear in the currently defunct ‘Impossible Pictures’, ‘Walking with…’ series. Among them were four extinct cousins of the modern crocodiles: Proterosuchus, Postosuchus, Metriorhynchus and Sarcosuchus. All four of them were different from each other, and while at least one of them – Sarcosuchus, (which also appeared in WWW), was physically similar to the modern crocodiles, ‘Guide’ made it a point to say that the modern crocodiles, caimans and alligators were only distantly related to their extinct cousins, which is true – if you put a modern species, say the saltwater crocodile, next to one of their Triassic cousins, you’ll get two different animals.

But what does their Triassic cousins look like? Postosuchus, Saurosuchus, Carnufex and co. looked like a cross between a modern crocodile and a mammal: they walked on all four legs, and those legs were directly beneath their bodies, as they are in mammals and archosaurs, (including birds), not splayed to their sides, as they are in lizards or tortoises, or even modern crocodiles. That is because they are only distantly related to them, and may be actually more closely related to the ancestors of the dinosaurs proper instead.

…Dinosaur phylogeny is confusing by itself; there are three main groups – theropods, sauropodomorphs and ornitishchia – aka the meat-eaters, the long-necked plant-eaters, and every other species. As a rule, the carnivores and the long-necked herbivores form one main dinosaur group – the lizard-hipped dinosaurs while the other dinosaurs form the second – the bird-hipped. Now, however, there is a suggestion that the carnivorous dinosaurs were more closely related to the bird-hipped herbivores, while the long-necked herbivores more closely related to the initial species, such as staurikosaurus, herrerosaurus, eoraptor and etc. It is a mess, and so far, there is no final verdict on it – and the same goes regarding whether or not dinosaurs were warm-blooded. Birds are, of course, while the crocodiles are not. Yes, the American alligator can handle cold temperatures, including cold snaps, which allows it to move further north in North America than its’ main rival, the American crocodile can. (Yes, there are two different species of the crocodilian reptiles in the modern North America). However, it is still very much cold-blooded, and it is not really related to birds either. (Aka the modern dinosaurs). Even the scientists who use alligators and crocodiles for models for dinosaur behavior do not deny that these reptiles are not real dinosaurs either, not literally.

In other news, as far as scientists are concerned, that when it comes to the archosaur family tree, the crocodiles derived first, followed by the pterosaurs, and finally the avian/non-avian dinosaur split. This means that the whatever evolutionary factors allowed some dinosaurs, (primarily birds), to become warm-blooded as the mammals are, (and mammals are a completely separate branch of the tree of life, BTW), never appeared in crocodiles, especially the modern species, but ditto for the extinct ones. The Triassic was marked, in the end, by a mass extinction, but it was not due to an Ice Age, but to a volcanic eruption instead and a prolonged drought, oxygen level loss, etc. Unlike the birds (and their ancestors) that appeared during the Cretaceous, neither crocodiles nor their ancestors had to deal with cold temperatures when they were evolving per se, and as such, they never did. This is why in the modern times crocodiles are restricted to the tropics, while the birds are not. They are warm-blooded, (as were their ancestors, apparently), while the crocodiles never were. To call the ancestral crocodiles ‘warm-blooded’ is doubly wrong. However…

However, aside from this gaffe, and the previously mentioned two mistakes, WWW is a good book for children. It tries to be both entertaining and educational and it does a good job at succeeding. True, the stories go all over the place, but so did R. Kipling’s ‘Just-So-Stories’, and they work well enough to become a classic in their own right, (cough Mowgli cough). Who knows, maybe one day WWW or one of its book fellows will become a classic in its’ own right. We will just have to wait and see.

This is it for now; see you all soon.

PS: And to all of you, a Happy Christmas for tomorrow