The case of the shrinking elephant tusks

elephantLast year I spent some time reading through Richard Dawkins’ The Greatest Show on Earth: The Evidence for Evolution with a friend. As Dawkins explains in his preface, while he has written a number of books about evolution, “I realized that the evidence for evolution itself was nowhere explicitly set out, and this is a serious gap that I needed to close.” So in this book he sets forth his best case for evolution, making it an intriguing book to contend with.

Some of his arguments have ready answers, and some do not, and my hope in sharing both the answered and the unanswered is that readers may be better prepared to contend with evolution, neither overestimating nor underestimating the challenge it presents.

At some point I hope to include a chapter by chapter response, but I’m going to begin with Chapter 5, because it is one of the most interesting. Dawkins titled this chapter “Before our very eyes,” and it is here that he shares what he sees as examples of evolution that occurred “so fast…we can see evolution happening with our own eyes during one human lifetime.”

Today we’ll take a look at the first example he gives, about elephant’s tusks.


Dawkins believes the African elephant may have “evolved” a smaller tusk size in the space of 33 years. From 1925-1958 the Uganda Games Department monitored tusk size and noticed a decrease in size that was “highly statistically significant, which means that it is almost certainly a real trend, not a random chance effect.”

Why are elephant tusks shrinking? Dawkins proposes that, because “hunters tend to pick on the individuals with the largest tusks” this “means that, at least in theory, smaller-tusked individuals will be at a selective advantage.”

While acknowledging this is merely a plausible explanation, and there may be others unrelated to natural selection he concludes “I am inclined to take seriously the possibility that this is a true evolutionary trend.”


Dawkins repeatedly speaks of creationists in his book – Greatest Show on Earth is supposed to be an answer to them – but this example left me wondering just how familiar he was with creationists and their arguments.


Because this example of “evolution in action” is one creationists could use to support our position. Creationists don’t find natural selection controversial. We believe change does happen, and quickly – after all, we’re the folks who believe that the vast variety of dogs we see today came from just a few kinds present on the ark!

So if elephant tusks are trending smaller over the course of a generation or two, that fits in well with the creationist model.

What it doesn’t do is offer any sort of evidence for the molecule-to-man form of evolution Dawkins supports. A smaller average for tusk-size is a horizontal change – no new information is needed, just selection from what’s already present. But for evolution of the sort Dawkins defends we need an explanation for a vertical change – how beings can grow in complexity, evolving from that single-celled creature to something elephant-size.

Either Dawkins is unaware of that fact creationists also believe in natural selection – which would mean he really needs to do his homework! – or he is knowingly and deliberately pulling a bait and switch here, presenting one form “evolution” in which the word means little more than “change” and offering that up as if it were proof for the very different sort of “molecule-to-man” evolution.

For more on this point see: