John Nord, age 10, of Spokane, Wash., for his question:

What were the first animals like?

The first living things were tiny, tiny creatures, too small for human eyes to see. They lived in the ancient seas, perhaps 2,000 million years ago. We have no first‑hand proof that these tiny creatures existed so long ago. Their bodies were just blobs of jelly, too soft to be preserved in the hard rocks. Though we have no perfectly preserved fossils of these little creatures, we do have some good second‑hand proof that they existed. Certain rocks can be made only with the help of living plants and animals, arid some of these rocks date back 2,000 million years or more.

One such rock is graphite, the so‑called lead in a pencil. Graphite is a soft, greasy black mineral, made mostly from carbon. It began as masses of plant life, beds of vegetation perhaps clogged in a swamp or shallow sea. After millions of years, this vegetation became coal. After more millions of years, the coal became graphite. Certain beds of graphite date back some 2000 million years. There are no pressed fern leaves or other evidence of plant life in this ancient graphite. We can only guess that the plants which made it were tiny one‑celled, algae perhaps like the fuzzy green algae which collected in our ponds and fish bowls.

Limestones and marbles are almost always made from the remains of tiny sea dwelling animals. Some of these rocks date back 2,000 million years or more, so we can be fairly sure that there were tiny forms of life on earth at this remote time. Through the long ages, the shell structures have been crushed and pressed out of shape by the movement of rocks in the earth's crust, We cannot prove what they were like, but we can make a very good guess. There are still countless little sea dwellers busy making limestone, chalk and marble. We can look at them and study them, for they are very like their remote ancestors who were the first living creatures upon the earth.

We call these one‑celled animals protozoa, meaning the first animals. They are in the first class of the animal kingdom and they are almost certainly similar to the first animals that ever lived. The members of one group are called foraminifers, meaning the window makers. They take chalky minerals from sea water and use them to build delicate shells. There are tiny windows in the shells through which the little creatures put out feelers to catch food, The members of another group are palled radiolarians. They take silica from the sea and build themselves hard, spikey shells..

Many of these protozoa multiply by dividing into two. There are no parents and children. When times are good, each little animal simply becomes twins. In time, each twin becomes twins. There is never any older generation to die out. These protozoa perish, only when they starve or meet with an accident. It is just possibly that some of them have been on earth since the very beginning, which was two or perhaps, three billion years ago.