The misinformation covers all aspects of science but my particular bugaboos are evolution, genomes, and junk DNA.
I'm going to quote the first few paragraphs from an article on the Knowable Magazine website. It seems to be associated with Annual Reviews and it certainly looks like it should be a credible source of science information.
The article is The silent majority: RNAs that don’t make proteins. The author is Christina Szalinski and here's how she describes herself on her website.
I know science.
I became a science writer in 2013 after finishing my PhD in cell biology at the University of Pittsburgh. So when it comes to writing, I can shake out the molecular tangles, unravel the cellular threads, and wade through the formidable details of scientific studies.
Is it wrong to specifically identify science writers who are spreading misinformation? Is it cruel or mean to imply that they don't understand their subject?
Do other science writers and their organizations have any obligation to police their own discipline to ensure scientific accuracy?
Does anybody have any good ideas on how to clean up this mess?
Here's an excerpt from the article. I don't think I need to explain what's wrong.
When scientists first cracked the genetic code, they expected a simple story: DNA makes RNA, and that RNA, known as messenger RNA, makes proteins. Proteins would do all the important work — building tissues, fighting infections, digesting food.
But when the DNA of our genome was finally sequenced, researchers encountered a head-scratcher: The 20,000-plus genes that carry instructions for making our proteins account for less than 2 percent of our DNA. What was the rest of it good for?
For years, the remaining 98 percent was dismissed as “junk DNA” — evolutionary debris, filler. But as sequencing technology improved, a startling picture emerged. Our cells were busy making RNA copies of all those expanses, not just making messenger RNA — or mRNA — from the protein-coding genes. They were churning out vast quantities of RNA molecules with no known purpose.
The question became: Why would cells waste so much energy on copying that junk?
Today, however, the importance of this non-coding RNA — the catchall term for RNA molecules that don’t carry instructions for proteins — is undeniable. Non-coding RNAs turn out to regulate everything from embryonic development to immune responses to brain function. They help determine which genes get turned on and off, and when. They can promote cancer or suppress it.
I contacted the author last week to warn her that I was about to publish this post. I asked if she wished to comment or to provide the source of her information on the history of the field. I did not get a reply.
The problem with this kind of description is that it misrepresents the way science is done. Most scientific models are due to slow and steady, incremental advances building on previous studies. That kind of science is (usually) self-correcting—when new information becomes available, the old models are revised.
The picture that is being presented to the general public is that old scientists were pretty stupid because they thought there was only one kind of gene (protein coding) and that everything else in the genome (98%) had to be junk. According to that false history, the old fuddy-duddies were shown to be totally wrong when the human genome was sequenced and thousands of non-coding genes were discovered for the first time. That disproves junk DNA according to the false history.
Is there a way of writing the true history in a way that's accessible to the general public? I don't know but I thought I would give it a try in order to try and show modern science writers how it coould be done.
It's not easy. Read my attempt below and let me know if it works.
Scientists were actively working out the functions of DNA back in the 1950s and 1960s. By the mid-1960s they had discovered two kinds of genes. The majority encoded proteins but there were also non-coding genes that specified important RNAs such as ribosomal RNA (rRNA) and transfer RNA (tRNA) that were used in protein synthesis.
Scientists also established that DNA contained regulatory elements that controlled the expression of those two types of genes. Other functional DNA elements were also identified at this time.
Most of this work was done in bacteria and their viruses where genes took up a very large percentage of the DNA in their chromosomes. However, it soon became apparent that this was not the case in humans where the coding regions of the protein-coding genes seemed to account for only 2% of the genome. (The genome is the total amount of DNA in all chromosomes.) Other functional elements, such as non-coding genes and regulatory sequences only accounted for a bit more of the genome.
This gave rise to a model developed by the leading experts of the time, including several Nobel Laureates. They proposed that only 10% of the human genome is functional and 90% is junk DNA. Based on a lot of experimental data, they estimated that there were about 30,000 genes in the human genome.
Additional non-coding genes specifying regulatory RNAs were identified at this time (early 1970s) but the biggest advance in this area ocurred in the 1980s with the discovery of a host of genes specifying various new RNAs. Some of these new non-coding genes specified RNAs that acted like protein enzymes to catalyze biochemical reactions. Others were involved in regulating gene expression and still others were structural components of large cellular complexes.
These results, and others from the 1990s, raised the number of non-coding genes in humans to as many as several thousand but they still only accounted for a fraction of the total number of protein-coding genes.
The first draft of the human genome was published 25 years ago and it confirmed the model developed more than 50 years ago. There were about 30,000 genes, just as the experts had predicted, and most of the human genome was junk.
Subsequent work on identifying features of the human genome have, by and large, confirmed this model but there are scientists who are skeptical.
Most of the human genome is transcribed into RNAs—a fact that was known 50 years ago—but many of the leading experts concluded that most of those RNAs were probably junk RNA of various sorts. The idea here is that the human genome is very messy and it gives rise to lots of spurious, accidental RNAs that are not biologically relevant. Most of those RNAs are present in small amounts and they are rapidly degraded. They are not conserved in our closest relatives. (Sequence conservation is a good indication of function and lack of sequence conservation is a good indication of junk.)
The skeptics, on the other hand, argue that most of those RNAs have a function and there are far more non-coding genes than protein-coding genes. The debate continues to this day.
1. And, unfortutnately, in the legitimate scientific literature.
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