Lori Treiber, age 11, of Sioux City, Iowa, for her question:

Do twins have identical fingerprints?

This week's mailbag brought more than 20 identical questions on this topic. But, as usual, only one person could be selected for the day's award. Let's hope that the others do not feel sad or mad. They can read today's answer and try again with a million more questions tomorrow.

A recent news item stated that identical twins could have identical fingerprints. This set off a surge of interested queries and Andy was as curious as everyone else. We have been told and told that no two persons have identical fingerprints. Reliable scientists have insisted that fingerprinting is a positive method of identification. That breezy news item shook our faith in scientific statements to the very core. But let's hold our horses until we read the results of Andy's up to the minute rechecking on the subject.

Let's begin with a practical look at the problem. In Washington D.C., the Identifi¬cation Division of the FBI has records of nearly 200 million fingerprints. Some are prints taken from identical twins. But scientific surveys scanned by reliable machines have found no two persons with identical fingerprints. In fact, no duplicate prints have been found in the whole world. Computers have estimated the chance of duplication is so slim that it is downright impossible.

Suppose we could collect the fingerprints of a billion trillion persons. Perhaps one of them might match your own prints or the prints of someone you know. But the test calls' for the cooperation of all the people now living plus all those who have ever lived on the earth and several generations yet unborn. It is not likely that your prints can be matched by anyone else's, even those of your identical twin. So let's relax and return to our former faith in fingerprinting as a positive method of human identification.

No two persons, even identical twins, are exactly alike. What's more, though our bodies have two sides, they are not exactly identical. There are slight variations in the two eyes, the profiles and other left and right features. There are wide variations in tie finely detailed patterns of fingerprints on the two hands. These distinguishing patterns are formed by ridges of microscopic bumps embedded in the derma layer of the skin. When damaged, this living derma re-grows its ridges in the identical pattern of grooves. Our fingerprints remain unchanged throughout life. Similar ridges of identification occur on the soles of our feet.

Many people assume that hospitals take the finger or footprints of every newborn baby. Andy's rechecking on today's topic revealed that this is not necessarily so. This is a pity. A simple card with the prints of a mother and her infant would be a foolproof record of life¬long identification. Babies, sad to say, sometimes get misplaced and toddlers tend to get lost. If their prints were on record, the strays could be returned to their rightful famil¬ies without doubt and without a lot of bothersome biological tests to prove who belongs to whom.