Question

If the sequence of one strand of DNA is written as follows.
ATG CAT GCA TGC ATG. Write down the sequence of its complementary strand.

Answer 1

The short answer to your first question is “yes, absolutely:” An adopted person can — sometimes — be fortunate enough to find the identity of their biological mother and father through one of the major commercial DNA tests available today. And the answer to your second question is “quite a lot.”

Let us explain what we mean by sometimes: if your biological parents or grandparents, brothers, sisters, or close cousins have already had their DNA tested, you will always be connected to them, and your relationship identified, by logging into your own privacy-protected account from the DNA company that tested you. We have to say sometimes because not everyone has had their DNA tested. But if every parent who put a child up for adoption had their DNA analyzed, that child would always show a connection to their biological parents in that same DNA database. We are a long way from reaching that goal but it is a noble one to which to aspire.

And the best part of this process is that it is affordable: Generally these tests, which analyze your autosomal DNA and automatically connect your results with people in the database with whom you share long stretches of identical DNA, cost less than $100. Before we explain how this miraculous process works, and give you an example of one person who found their parents in this way, we want to pause for a moment to discuss this very normal human impulse to find one’s birthparents. This quest for clarity about the biological basis of our family’s lineage has been encoded in the myths and sacred scripts of human beings for thousands of years.

Establishing the names of our fathers has a long history in many cultures, notably in the West but also in civilizations like the Chinese, among many others. For members of the Navajo nation, an introduction begins with one’s first name, followed by one’s mother’s and father’s first clans, then one’s maternal and paternal grandfather’s first clans. An example quite familiar to Christians, Jews, and Muslims is the Book of Genesis, which scholars believe was composed about 2,500 years or so ago. Chapter 5 of Genesis, which lists the male generations who connect Adam with Noah, surely must be the oldest family tree in Western civilization. We are all familiar with how this first human family tree begins: “And Adam ... begat a son in his own likeness, after his own image.”

These key words — “in his own likeness, after his own image” — were the ancient world’s way of describing the fascinating process by which parents share their DNA with their biological children. Though texts like Genesis were explicitly concerned to name paternal lineages, the Bible is also careful to name the “foremothers,” great female figures in history. These are lines of descent, based on a biological connection, and they were quite important in establishing property rights and shares of inheritance when a patriarch died. Many scholars