News Response: to “The inner Life of Cells”, Newsweek, Page 8, 9/17/12 by Kent Sepkowitz
This is a “short” commentary:
In “The Inner Life of Cells” (Newsweek, page 8, 9/17/12) author Kent Sepkowitz informs us that “Scientists made a splash this week when they presented a radically new view of DNA…” The old view was that there was “junk” DNA – a large volume of DNA which didn’t seem to do anything. The new belief is that the “junk” DNA regulates middle management of DNA related activity – turning genes or gene activity on or off.
Really, the whole notion of “junk” DNA has been easily questionable from the outset, just as the long touted quip “we only use 10% of our brain” has been easily questionable from the outset. Any broad view of nature and evolution reveals that these are very smart processes, given the parameters of life on the planet. While we see great diversity in life, we don’t see that individuals have lots of wasted structure or functions. Therefore, both the notion of “junk” DNA and wasted brain must be immediately suspect.
Early scientific work on the brain included investigators doing gross electrical stimulation of brain parts and then looking for what happened – something twitched, some function became evident. Investigation also proceeded by looking at brain pathology in injury or disease and seeing how the brain pathology correlated to observed looses of function. By these techniques a great deal of brain didn’t seem to do anything. However, a great deal of brain power (arguably its greatest portion) is devoted to highly complex tasks like making extrapolations, synthesizing bits of data into “the big picture”, weighing choices, arriving at judgments, and such. These tasks are much more complex and resource consuming than simply making a leg twitch, which is why a frog can twitch a leg but can’t ponder the nature of the universe. And, these complex tasks don’t show up when a brain is electrically stimulated, or show up as losses in simply studies of pathology.
The real story is that we use all of our brain – maybe not all the time, and maybe not when effort is lacking – but we do use all of our brains. There is no evidence that nature makes structures that are never used by anyone, as the “we only use 10% of our brain” concept would imply. What is routinely far more evident is that we do not understand why something is as it is, that we do not understand the sense it actually makes.
By the same concept, it is arguably unreasonable to presume that nature makes us carry around “junk” DNA. The wonder of evolution and diversity clearly reveal that nature is smart and basically efficient. The idea that we would have lots of “junk” DNA just doesn’t fit with the big picture. For example, how many body parts do we have that we don’t use? Yes, during development there are some structures, like branchial clefts, which pass through a stage of manifestation that changes later in development – testimony to the dictum “ontogeny recapitulates phylogeny”. However, in the normal state all structure does change into something useful.
Therefore, the more pertinent question should be: What actually is the function of the “junk” DNA? The “splash” discovery announced last week is that much of this DNA works in middle management of genetic activity. However, this is certainly not all of the story. A great deal of genetic material must serve behavior.
We typically think of genes as building what we ARE – our form and basic functions. But it must certainly be true that many genes build what we DO. Dogs act like dogs. Cats act like cats. Retriever dogs have specific behaviors that “come with the breed”. In many, many forms we must easily observe that behavior is often genetic. All manner of biological organisms show behaviors that are typical of the organism – even in those cases where the parent departs the offspring at birth, such as in the case of migrating turtles. We accept this easily in animals. We don’t like to apply the concept to ourselves. But this is a social rather than biological commentary. Patterns of behavioral response are frequently transmitted by genes and those genes would appear to be “junk” if we sought to correlate them to body structure.
Consider, for example, the monarch butterfly. This amazing creature is known for its yearly migration from Mexico to Canada, and back. But, the same individual does not make the whole trip. In fact, it takes four generations of butterfly to make the whole trip. Since no one individual makes the entire journey, how does any individual know how to make the journey? The answer is genetic behaviors – genetically passed information which transmits not only what to expect in the journey of life but also how to respond to it.
So, without carrying on too long here, the ideas of “junk” DNA and “unused” brain are testimony to our lack of insight rather than wasted efforts by nature. Nature simply doesn’t work with such inefficiency. Both of these perspectives are succumbing to “new” information that is actually obvious when one looks at what nature makes evident.
Antoine de St. Exupery commented on this when he said, “More wisdom is latent in things as they are than in all the words men use.”