Turn on the television on any day at any time, and you will be sure to find at least one show featuring animals; open any book, and there will almost surely be at least one reference to animals.
While it may seem that we live in an entirely human-dominated world, animals are in fact all around us: in reality, in myth, and in symbolism. Animals have continued to fascinate, to entertain, to command people’s attention throughout time, and while the relationship between humans and non-human animals has not always been one of respect, it has throughout time remained one of awe.
What is it about the animal world that so fascinates us? Is it the seemingly endless diversity of species, the similarities in form or behaviour between so many animals and ourselves, or the marvelous ingenuity of design that pervades the animal kingdom? Undoubtedly, each of these factors plays a role in our unending interest in the world of animals.
The Kingdom Animalia is broken down into the categories of Phylum, Class, Order, Family and, most familiar to the layperson, Genus and Species. This kingdom, to which we humans also belong, is filled with creatures so strikingly different from each other that within such a grouping can be found everything from the delicate, sessile sponges of the sea floor to the mighty elephants of Asia and Africa. While sponges and elephants, Amoebas and humans are linked in this classification system at only the most general level, such linkage indicates a common ancestor, one organism from which we, through a process of evolution, all emerged. Yes, it is true that we split off from this shared ancestry many, many aeons ago. But how, and why?
Evolution, the process in which organisms undergo alterations in behaviour and form, is understood as being intricately linked with something called natural selection – better known to many as the scenario of survival of the fittest. As a result of natural selection, any given organism is considered to be that which is best adapted to the environment as it is in that place, at that time. As the environment changes, so must the organisms dependent on it if they are to persist.
One of the most intriguing aspects of zoology, or the study of animals, is investigating exactly that: the adaptive features of animals in relation to their environment. Some adaptations seem so logical, so ingenious, that one can hardly believe evolution is thought of as a random process.
Take the English moth species that, during the industrial revolution, transformed from a light beige colouration to a dark charcoal colour. Why such a change? As the trees on which this moth rested became increasingly covered in airborne soot, and thus changed from a light bark colour to black, beige moths were suddenly maladapted to their now-changed environment. These light-coloured moths were no longer well-camouflaged, and became easy prey for a predator on the lookout for a tasty snack on a sooty tree.
The story goes that over time, those moths which by random mutations of the genes emerged from the pupa darkly coloured, and thus well-camouflaged on the soot-covered trees, were best able to survive in the changed environment in which they found themselves. As survivors, it was these dark moths that were able to reproduce, thus creating more moths just like themselves, and eventually creating a strain different from that common in pre-industrial times. This moth can be seen to have gone through a rapid evolutionary process in which, through natural selection, a randomly-generated dark coloured moth became that best able to survive and reproduce. An evolutionary event witnessed in our own time: Fascinating without a doubt.
What about those creatures that sport what can only be thought of as some kind of maladaptation? What can be said about those species with features that just don’t seem to fit their environment; how can the presence of their particular way of coping with their surroundings be explained in the evolutionary terms discussed above? One of the most common situations in which are witnessed what appear to be maladaptations is where a species utilises more than one habitat type. Picture the seal, sea lion, or walrus: exceedingly clumsy on land or ice, but magical swimmers in their primary habitat: the sea.
Another of my personal favourites is the Red-necked Grebe. A phenomenal swimmer and quite a flyer, this diving bird seems equally at home in the water as in the air. But goodness gracious, whatever you do, Grebey, do not make a touch-down on land. This bird, which occasionally ends up on terra firma as a result of accident or miscalculation, will find itself land-bound, unable due to its specialized, lobed toes, to move about on the ground. Wildlife rescuers are, from time-to-time, called upon to relieve these poor birds of their land-locked state, and to replace them to their primary habitat: the water. Without such assistance, the unfortunate Grebes would have perished, stranded and alone on foreign soil.
From an evolutionary perspective, is the lobed toe then a maladaptation, something which makes the bird rather ill-suited for its environment? The Grebe, which frequently must fly above land in its travels from one water body to another, is literally stranded if it miscalculates and ends up on the ground. How, then, could one say that the Grebe is best suited to its environment?
The answer lies in looking at what, in fact, comprises the main environment of the Grebe as a species. The lobed toe is the feature that makes Grebes such strong swimmers, such strong divers, and such successful under-water hunters. Thus while the lobed toe acts in a maladaptive capacity while the bird is on land, any negative impacts it may have in the occasional Grebe’s life is more than made up in the population by being a decidedly positive adaptation to life in the water. Thus, when trying to understand an animal’s adaptations, we must always ask, ‘adaptation to what’? The Grebe is perfectly adapted to life in the water. The presence of land between the water bodies to which it is so well-adapted is simply a royal pain in the occasional individual Red-necked Grebe’s life:
Ah evolution, something to ponder on these long winter evenings, something to remind us of the never-ending wonders of the outside world as we remain huddled inside in a state of quasi-hibernation. Constant, ever-changing, and resulting in endlessly novel forms of life, evolution in the animal kingdom is something to behold. Sometimes amusing, occasionally baffling, the adaptation of animals to their environment is always awesome. Here’s to a continuing fascination with the animal world, and a growing recognition of the wonders our kingdom has to offer.
Zoe Dalton is a graduate of York University’s environmental science program, and is currently enjoying working towards a Master of Arts in Integrated Studies with Athabasca U. She can be reached for comments or questions at firstname.lastname@example.org.