Each week on the NPR radio show “TED Radio Hour” host Guy Raz loosely assembles a theme from three or four “TED Talks” that he found interesting, and he then interviews the selected TED lecturers to dig a bit deeper into the theme — which typically deserves some deeper digging.
This past week, Mr. Raz’ theme was “What Makes Us… Us?” Some people would argue that “what makes us.. us” is coded into our DNA. Among them is Sam Sternberg, one of the guests on Mr. Raz’ radio show last week.
The conversation began with four letters — C, G, A, and T — signifying the four amino acids that form the apparent informational core of a DNA double helix: “C” (for cytosine,) “G” (for guanine,) “A” (for adenine,) or “T” (for thymine.) Four letters, repeated endlessly, over and over in various combinations.
“The same four letters that every species on the planet has.” So says Mr. Sternberg.
Your might say this put us (as life forms) slightly ahead of computers, which operate with only two possible states: 1 or 0.
If you were to print the four-letter code for one person’s DNA as one long sentence, the sentence would take up about 800 books the size of the English dictionary, says Mr. Sternberg. He apparently believes that everything about you — your physical traits, the color of your eyes, your personality — comes from this string of four basic chemicals. His is not an unusual belief, I think, among the scientists who deal with genetic modification.
This belief got its start in 1953, when a couple of scientists named James Watson and Francis Crick came up with a new theory: that the particular and unique ordering of four chemical components — C,G, A, and T — in a certain double-helix pattern defines the essential characteristics of each particular and unique living organism. And if you swap out pieces of the DNA, you can change the organism.
Sam Sternberg discussed his view of scientific reality on the TED stage:
“We’ve known for over half a century that DNA contains the blueprints to make all living things. The genome can tell is a lot about ourselves: about our ancestry, our traits and our disease susceptibilities. But there are things in the genome that you might not want to find out.”
You might not want to find out, for example, that your DNA predisposes you to suffer from cystic fibrosis, or Huntington’s disease, or Alzheimer’s.
Or maybe you really do want to find it out? If your DNA could be “fixed?”
Mr. Sternberg did his Ph.D. work along side Jennifer Doudna, the University of California researcher who developed the CRISPR/Cas9 system of gene editing. The system, developed in 2012, relies on a particularly talented protein found in the bacteria Streptococcus pyogenes, that can attach itself to a strand of DNA and replace one particular C,G,A,T combination with a new combination. Since 2012, CRISPR/Cas9 has reportedly been used to alter the DNA in zebrafish, fruit flies, mice, monkeys.. and human embryos. As of last week’s NPR radio show, it sounds like CRISPR/Cas9 has not yet been used to change the DNA of a living human being. But how far off can that be?
In 1974, Monsanto introduced a weed killer called glyphosate. Glyphosate kills weeds by blocking proteins essential to plant growth. It’s now used in more than 160 countries, with more than 1.4 billion pounds applied per year — often under the trade name ‘Roundup.’ According to National Geographic, “Nearly all the corn, soy, and cotton now grown in the United States is treated with glyphosate.” Between 1987 and 2012, annual U.S. farm use grew from less than 11 million pounds to nearly 300 million pounds — because Monsanto created genetically-modified seeds that grew into plants resistant to Roundup. Like the GMO corn plants that supplied the corn and corn oil in my bag of Fritos…
The GMO corn in my corn chips was given an artificial resistance to glyphosate by the folks at Monsanto, which means the farmer can spray my food all day long with glyphosate, and the corn crop will continue to grow. The USDA does not require testing of glyphosate content in foods, because the particular protein pathways blocked by the chemical are not present in mammals. Glyphosate is supposed to be harmless, except to plants.
But the EPA recently announced it will analyze new findings by the UN’s International Agency for Research on Cancer, which declared in 2015 that glyphosate probably raises the risk of cancer in people exposed. The UN agency based its decision on human, animal, and cell studies. The studies found glyphosate in farmworkers’ blood and urine, chromosomal damage in cells, increased risks of non-Hodgkin lymphoma, and tumor formation in some animal studies.
As mentioned in Part One, yesterday, there are now more than 26 species of weeds that have developed their own resistance to glyphosate. How amazing is that? None of these weeds had access to the Monsanto laboratories, or to fancy gene-splicing technologies. They were just stupid old weeds, living out in the field.
But somehow, they learned, on their own, how to resist Monsanto chemicals.
We could take a lesson from them.
Bill Hudson began sharing his opinions in the Pagosa Daily Post in 2004 and can’t seem to break the habit. He claims that, in Pagosa Springs, opinions are like pickup trucks: everybody has one.