Is DNA Alive?

No, it’s not alive…mostly. The only sense in which a DNA molecule is a living thing is that it makes copies of itself, although it can’t even do that on its own. Otherwise, DNA fails all the tests: it doesn’t process anything in order to maintain its state, it doesn’t grow and develop, so it has no energized activity that starts or ends—in other words, it’s not born and it doesn’t die.

Somewhere along the line in reading general science I picked up the impression, even though I think I knew better, that DNA strands are alive. They are such vital keys to living organisms, and I read so many descriptions of what DNA does and of “selfish” genes, that although I knew they were blueprints of a sort, they came to seem like living blueprints.

DNA and seed (kew.org)

DNA and seed
(kew.org)

One image that took shape in the back of my mind was that DNA was a kind of seed, and seeds, I thought, are alive. But no, seeds are not fully alive either. They are not active and, until they germinate, they don’t change or develop. (Another familiar item that may seem alive but that doesn’t meet all the criteria are viruses. Viruses are bundles of DNA that become active only when they are inside a cell, at which point they take over the cell and give us the flu.)

It shouldn’t be surprising that some familiar biological components do not, by themselves, meet all the criteria for the complex condition we call “being alive.” Still, surprised I was about DNA. Perhaps because we humans are so fully aware that we are alive, it is easy to think that there must be a fully living seed or even a soul at the root. It is almost more than we can imagine that the liveliness we feel is the product of a complexity of non-living parts. It’s an astounding thing.

2 thoughts on “Is DNA Alive?

  1. The definition of life has always been a bit tricky, even for biologists. One relatively straightforward definition states: “the condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death.” But there certainly are some gray areas, as you note with viruses. They are essentially intracellular parasites that require the functional infrastructure of a cell to carry out the requirements for being alive. But, what about other parasites such as some worms? Many would say that they are alive, but they too require another species to survive. While it is fairly straightforward to say that DNA is not alive, what about functional RNA that contains both information and enzyme activity? And then there are prions, etc…. Bottom line is I don’t worry too much about it the definition 🙂

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