And Other Life Forms?

Many life forms have no distance senses, relying on contact and internal senses. Plants, for example, cannot see, hear, or smell, although some plants can sense pressure or vibration. Even some simple members of the animal kingdom, such as the amoeba, have no distance senses, relying on physical contact for information about food and predators. The psychological world of these creatures is limited and immediate.

Our distance senses provide a more comprehensive picture of the world around us. We can detect predators, and escape or avoid them; we can locate prey, and try to capture it; we can find resources like water, shelter, and tools, and take advantage of them—all by using our distance senses.

Distance senses work in harmony to achieve these ends. We may hear a babbling brook long before we see it, but we realize that water is nearby and know which direction to take. Once we get in the general vicinity of the brook, we see it and walk confidently to the water's edge for a welcome drink. We may smell a predator but not know precisely where it is lurking, then listen and watch for more signs of the stalker. All this knowledge comes to us without direct physical contact, the hallmark of distance senses.

Creatures that enploy distance senses have a tremendous advantage over animals that cannot sense at a distance. If we had to rely on physical contact to alert us to a predator, it would probably be too late!