Humans often wonder why we are here. It’s a fascinating question that becomes even more fascinating when we realize what we, and our cells, are really made of.
Trying to comprehend how life began is a bit like trying to imagine what’s on the other side of the edge of the universe. How can there be an edge? It’s hard to grasp that living things are a complex and marvelous product of chemical reactions. How can it be just chemistry?
Two personal revelations stand out for me. One was aided by a microscope, the other, a book. Through the microscope, I saw a ciliated respiratory epithelial cell—one of the cells that line our respiratory system like a field of little automatic brooms, sweeping debris and mucus up and out of the lungs—still busily sweeping in salty solution hours after leaving the body of the person who built it. In the book, I read that scientists believe that mitochondria—the tiny energy producing organelles inside cells—were once organisms themselves that got taken in by larger cells and didn’t die.
Astonishing! Our cells are individual life forms that can live without us as long as their needs are met, and even they have other life forms—or the descendants of other life forms—inside them, allowing them to function. We are built of innumerable individuals that function together to make an organism. It gets even stranger: DNA, the molecule directing all the functions of a cell is made up of elements that have come together through chemical reactions that have little to do with life—but resulted in life. It is, indeed, stranger and more marvelous than fiction.
See Theories of How Life Began for current scientific thought on how those chemical reactions first happened.
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