Guest Author - MaryEllen Schoeman
Why is it, that when we see a baby mammal, any baby mammal, we all have the urge to cuddle it? No matter how fierce we may know that adult version of the animal to be, babies inevitably make us say "Awww! Cute!" But how does that work?
Baby mammals all have certain characteristics that tend to inspire care-giving. These are the characteristics that we usually call "cute". For example, disproportionately large eyes and/or heads (both of which are seen in baby humans, for example), limbs out of proportion to the body (long and delicate, like foals, or baby deer; or short and stumpy, like puppies and kittens), and blunted/non-threatening snouts and ears in the case of predatory mammals.
Almost all humans respond to any of these characteristics with an urge to protect, and many mammals will respond to these features even in the young of other creatures if that mammal's own young have that feature. (This is responsible for examples of dogs adopting kittens and so forth - both kittens and dogs feature similar infant features - blunted snouts, large eyes). Excessive fuzziness is also characteristic of almost all mammal young, and serves different functions in different animals. Mostly it is a thermo-regulating device, as baby animals are often not able to fully control their body temperature yet, and some are often left alone without mother's warmth for long periods. Sometimes the fuzziness also is used as protective coloration - baby cheetahs, for example, have long fuzzy fur on their backs, because cheetah mothers don't den, and "hide" their babies while they go hunt, and the longer fuzzy fur helps them to blend in with the tall grasses. Deer mothers also hide their young, and fawns have spotted fur to help them blend into dappled shade more effectively. In motion, however, the spots work against the deer and become targets, which is why they lose their spots as they get older.
When these childhood features are carried over into adulthood, it is called "neoteny". Many predators have neotenic features, which help to make them look less threatening. Bears are a good example. Bears have short, stumpy-looking legs, broad faces with blunted snouts, and are very fuzzy. This is what is responsible for our inevitable "ooh, cute" response when we see bears. And that response leaves us at a disadvantage when dealing with bears - We're standing there looking at the bear and saying "Ooh, cute!" while the bear is looking at us and thinking "Ooh, food!" For a predator, this is a big advantage.
The neotenic features of predators may have evolved at least partially to give them an advantage in hunting by looking less threatening, but they also benefit the animals in other, more direct ways. The short powerful legs of the bear, along with the flat feet that give it its cute shuffling walk, also allow it to stand on its hind legs, giving it an advantage in searching for food. The heavy fur keeps it warm in cold weather, and protects its skin from branches and brambles in the woodland habitat in which it lives. So in this case, we have features that provide advantages to the animal in many ways.
A similar mechanism is probably at work with prey animals that have very neotenic features, such as the gerenuk, which looks for all the world like an infant deer without spots. An appearance of youth or innocence is really of no benefit to the gerenuk. Rather, the very long legs have evolved so that the gerenuk can reach higher into trees to browse for food, which gives it an advantage over other, shorter browsing animals. The large ears probably serve a similar function, allowing the animal to hear the approach of potential predators. So in this case, the infant appearance of the animal is a side effect of traits evolved for other purposes.
This all brings us to an interesting and important point. When talking about how evolution has shaped the features of animals, we have a tendency to simplify it to one or two "reasons" - the giraffe has a long neck because it allows it to eat from higher up, for example. But evolution and natural selection are rarely that easy. The interplay of environment, selection, genetics, and pure accident can result in all sorts of adaptations, some of which become incorporated into the species and some of which do not. While the fossil record tells us how different animals evolved, it does not tell us why - we really can only guess at why different features evolved based on what we know about the present-day animal. So we can say that bears have neotenic features, and those features have a particular effect on other mammals, but we can never know if that is truly the reason that bears have evolved with those features. We can say that gerenuks probably did not evolve their neotenic features for the same reason, but really we don't know.
In the meantime, next time you see a bear, please remember that while bears are really cute - it's best not to try to cuddle them.
