Tag: Junk DNA
Discovering Signs in the Genome by Thinking Outside the BioLogos Box
Yesterday I promised that I would show you a mysterious genomic signal, and today I shall fulfill that promise. The previous blog was devoted to describing the linear distribution of LINEs and SINEs along mammalian chromosomal DNA. We saw that L1 retrotransposons tend to be densest in the regions where Alus and Alu-like elements are the least common and vice versa. I included the following figure from an article co-authored by Francis Collins1 that showed this compartmentalization of LINEs and SINEs along over a hundred million genetic letters of rat chromosome 10: The blue line indicates the distribution of SINEs along a 110-million base pair interval of rat chromosome 10. (From Fig. 9d of Ref. 1.) Taxon-Specific Elements: The SINEs Read More ›
Ayala and Falk Miss the Signs in the Genome
In his recent response to Stephen Meyer’s Signature in the Cell, Francisco Ayala claimed that repetitive portions of our DNA called “Alu” sequences are “nonsensical.” Ayala wrote: “Would a function ever be found for these one million nearly identical Alu sequences? It seems most unlikely.” In his response to Ayala, Meyer showed that Ayala is factually wrong about this. According to recent technical papers in genomics, Alu sequences perform multiple functions. In a rejoinder to Meyer, Darrel Falk defended Ayala and claimed although “a number of functional regions have been discovered within Alu sequences,” there “is no question that many Alu sequences really have no function.” In my last blog, I showed that the vast majority of the genome is Read More ›
A Response to Questions from a Biology Teacher: How Do We Test Intelligent Design?
A biology educator recently wrote me asking how we test intelligent design using the scientific method, how ID is falsifiable, and how ID explains patterns we observe in nature. These are very common questions that we receive all the time from teachers, students, and interested members of the public, and they’re usually legitimate, sincere, and thoughtful questions. In this case, they certainly appeared to be such, and below I post a slightly modified version of my response to the teacher, withholding any information about the teacher to protect his/her identity: Dear [Snip], Greetings and thanks for your e-mail. ID is most definitely testable and falsifiable. It uses the scientific method and explains many patterns we observe in nature. Let’s start Read More ›
Asking Darrel Falk to Pick a Number, Any Number
I have long questioned the assumption that most genomic DNA sequences are “nonsensical” or “junk.” And given the data that have emerged over the past seven or so years, a functionalist view of genome has robust empirical support. It is for this reason that I think many of the arguments presented by the Biologos Foundation are “wrong on many counts,” to borrow a phrase from Darrel Falk. Here is an example. While reading the “critique” of Steve Meyer’s book, Signature in the Cell, by Francisco Ayala, a number struck me that I know to be incorrect. The integer that I am referring to is “25,000” and it is claimed to be the known tally of genes in our chromosomes: The Read More ›
Convergent Evolution of Introns Challenges Common Descent and Random Mutation
A recent article in ScienceDaily titled “ Introns Nonsense DNA May Be More Important to Evolution of Genomes Than Thought,” actually demonstrates nothing like Darwinian evolution. Introns are stretches of DNA within genes in Eukaryotes that do not code for proteins. But they aren’t functionless and can play important roles in splicing together proteins. According to the ScienceDaily article: “The scientists also found what appear to be “hot spots” for intron insertion — areas of the genome where repeated insertions are more likely to occur. This implies the occurrence of convergent genetic evolution of introns at specific locations, or as the article repeatedly puts it, “parallel intron gains.” The study’s principal investigator, Michael Lynch, was clear about the implications: Michael Read More ›