Scientists can be a stodgy lot. Although they often deal with the fantastic, the bazaar, and the wonderful, these creatures are obliged to maintain a reserved attitude, as though stoicism was a necessary accessory to wear with a lab coat. Occasionally, however, one may find a tell-tale stirring within those reserved exteriors, a perceptible blip on the pulse meter during unguarded moments when certain phenomena are being discussed. Such is the case with the description of an event that, curiously enough, none of us has ever witnessed. Charles Darwin, a man himself no traitor to the cause of scientific stoicism, referred to it as "the abominable mystery." Strong words from a man who rarely strayed from understatements.
To understand this event imagine for a moment a world somewhat like ours but devoid of some of the details that lend our world interest. For instance, this world has little innovation in the way of plants. Forests can be found but these are forests lacking diversity -- mostly pines and firs, some tall fern-like organisms and ferns themselves, but little else. Mosses and algae are common in swampy niches, but for the most part there is much bare ground, partly because there are no grasses. Nor are there fruit trees, palm trees, herbs or cactus. This is an exclusive but unimaginative club of food producers.
Without grass there are no grazers -- no buffalo, zebras, wildebeests, stretched-necked giraffes or long-eared rabbits. In fact, without seeds, such as those found in the grasses like rice, wheat and corn, and without the tubers of plants like those found on the biannual carrot and parsnip, there's no point in expecting a world to be inhabited by very many of the type of organisms that we call warm-blooded, because those animals require a great deal of energy to maintain their active metabolisms. In the world I am describing there are a few such animals, but by and large the animals that do exist are limited by their own energy requirements.
The world I am describing existed here on our own planet about 150,000,000 years ago. This also happened to be the period of the dinosaurs. It is suspected many of these huge creatures were warm-blooded, but they were limited to a tenable existence because the herbivores among them (which comprised about 90% of all species) had to grind down an enormous amount of energy-deficient greenery just to stay alive, and this dictated what they did most of the time. It also limited the prospects for possible new models to be introduced by the evolutionary process.
Up until this moment the earth from space must have looked unremarkable at a distance to any jaded interstellar tourist, with its broad expanses of blue water broken up here and there by large fragments of brown earth interspersed with splotches of green where the cone-bearing forests grew. But if our imaginary visitor had the ability to follow a short period of geological history, than he (or she, or it) would have been rewarded with something quite phenomenal. Somewhere a great experiment had been performed, and it was so successful that it totally changed our planet with unprecedented speed. It was a biological revolution, a silent explosion, and its effect was so pronounced that it is hard to be believe that an entire planet could be so irreversibly affected by something as fragile and delicate as -- a flower. This was an invention that followed soon after the advent of the seed, and, as I have mentioned, that was a remarkable event in its own right. This is because the flower allowed the plant a capability it never had before -- advertisement. Now the plant could carry on sexual reproduction with distant members of its species without having to move. It could do this because it could offer high grade energy in the form of sugars, and this allowed the introduction of many organisms that were more than happy to cooperate. A partnership was born.
Within a short period of time flowers of all sorts were taking over every corner of the world and with them arrived bees, wasps, butterflies, nectar- loving beetles, birds, and even mosquitoes and flies. The world exploded into colors never before seen on the planet. And among the flowering plants were the family of grasses and grains which, with their high energy seed, made possible the evolution of an animal never before seen on this planet, the grazing mammal. Some flowering plants went one step further and surrounded their seeds with the energy rich flesh of fruits so that the seeds could be carried elsewhere and deposited with the droppings unharmed. This encouraged the evolution of animals that subsisted primarily on fruits and nuts alone, and then, of course, there was the arrival of the flowering ancestors of our modern day carrot, potato, radish and mustard. The arrival of all these new forms of living things reverberated throughout the planetary ecosystem. Nothing would ever be the same again.
All this transpired within an eyeblink in geologic time. No other event in the history of the planet occurred with such quickness or affected so many other living things. This truly was a magical event, an episode that can easily stir anyone's imagination, and even a sedate biologist or two has been known to pause in wonderment when contemplating its significance.
S. Brown