Friday Pearl

Bias and Science

Wednesday, May 15, 2019


I admit it. I’m biased. When I read controversial articles my biases influence my reaction to the claims of the author. I’ve been a Life Member of the National Geographic Society for many years and tend to accept the conclusions of NGS writers as valid. But when I read in the March 2015 issue that some of my beliefs had been challenged by recent science, my biases kicked in.

I had long felt that genetically modified organisms (GMOs) were bad, because some experts had said they were bad. But more experts have publicly stated that genetically modified foods are safe and beneficial, pointing out that the scientific evidence to the contrary is still controversial. The NGS authors point out that there is no reason to believe that altering genes precisely in the laboratory is more dangerous than altering them through traditional cross breeding.

To some people the idea of transferring genes between species is abhorrent, conjuring up images of mad scientists in secret laboratories.  As I continued to study and review the literature I realized that there were good (and natural) GMOs and there were potentially bad (synthetic) GMOs.

Humans have domesticated plants and animals since around 12,000 BC using selective breeding or artificial selection (as contrasted with natural selection).  The process of selective breeding, in which organisms with desired traits (and thus with the desired genes) are used to breed the next generation, and organisms lacking the trait are not bred is the oldest form of genetic modification by humans. When DNA and nuleic acid sequences are combined in the laboratory, the resulting DNA is called recombined or recombinant DNA. Recombinant DNA may contain bits of DNA bits from the same or similar species, or may contain bits from different organisms that could not naturally interbreed (transgenic).  Recombinant DNA may also contain synthetic or chemically altered sequences.

The first recombinant DNA molecules were produced in the 1970s by direct manipulation (genetic engineering) of genes. Whereas selective breeding depends on naturally occurring genetic variation within a population or species, genetic engineering can involve the intentional introduction of genes from different species. Advances have allowed scientists to manipulate, remove, and add genes to a variety of different organisms to induce a range of different beneficial traits. From 1976 the technology became commercialized, with companies producing and selling genetically modified foods and medicines.

I don't have a problem with genetic engineering or GMOs produced by gene manipulation, but I do have problems with synthetic or chemically altered GMOs. I support the work and objectives of the Union of Concerned Scientists in this regard. I realize the jury is still out on this, but just as I try to avoid pesticides in my foods, I buy organic as much as I can.

Spencer Thornton, MD