November 2021

There are just three types of animals on planet Earth if you classify them by eye function. 1. Those that have forward vision only, like us and most spiders, these animals are usually predators; 2. those that have side-of-head eyes, virtual all-round vision such as chickens and butterflies, these tend to be prey animals 3. those that have no eyes, like worms and cave fish, live in dark places and have lost or never found the power of vision.

Eyes may be the single most improbable and miraculous organs of the body, a window on the world. Even the Evolutionary Biologist Charles Darwin exclaimed that it was “absurd” to propose that the human eye evolved through spontaneous mutation and natural selection. Yet evolve they did because evolution itself is an elegant and miraculous process.

Actually, even worms have cells that detect and inform them as to whether they are in darkness or light. From simple light sensors like these, eyes developed and improved gradually over many generations.

Predators and prey alike probably have the best eyes on the planet as their existence depends on them. A golden eagle has phenomenal eyesight and can see tiny prey movements from hundreds of metres away. Similarly, deer and antelope who have all-round vision, and who often live in herds, will spot a predator immediately unless the latter is well camouflaged, hidden and still. Feeding and survival for these 2 groups has been a process of refinement and skill development over many generations. The same can be said of humans as athletes continue to break records every year at sports meetings. We no longer depend on the skills and agility of hunters in order to eat, but we still try to improve the capabilities of our bodies. Animals will be doing likewise. However, some animals, like us, have adopted a cultivation strategy for their food. They still need good eyes, but use them for management rather than hunting or evading being hunted. Among these are ants who ‘farm’ aphids and scale insects. Lions who live with herds of antelope, getting to know them and identifying individuals that would be easiest to catch.

Autumn is the time for spiders, hunters that set gossamer insect traps.