Genetics

Here’s todays headscratcher from Phys.Org. It appears that to contrive a “mature” micro-RNA (mi-RNA), involved in gene regulation, the cell requires hundreds of kilobases of sequence. How odd. “Mature” mi-RNA’s are ~22 bases in length, and hundreds of thousand of nucleotide bases are needed (of primary-mi-RNA) to effect this ~22-nucleotide regulatory element? Here’s what they say: MicroRNAs are short noncoding RNAs that play critical roles in regulating gene expression in normal physiology and disease. . . . Although mature miRNAs are only ~22 nucleotides, their transcripts are up to hundreds of kilobases long. Primary miRNA transcripts, or pri-miRNAs, are quickly processed into mature miRNAs from hairpin structures located in the exons or introns of pri-miRNA transcripts. One remarkable feature of Read More ›

Here’s this snippet from a Phys.Org entry. The most remarkable part of it is that they link “cell-type” evolution to the repression of genes, making one wonder if all the necessary genes needed for all of life was somehow present in an original genome. Obviously there are problems with this thesis in terms of genome length and type, bacterial genomes being ciruclar, while animals generally have discrete chromosomes, but, it’s entirely possible that multi-cellular life represents a complete break with bacteria, and that what we’re seeing here is the ultimate in “front-loading,” where everything is in place, yet, per Behe’s first law of adaptation, we see “loss of function” leading to novelties. And, it should be a little troubling, if Read More ›

Further to Philosopher of science: Schoolbook Darwinism needs replacement (Witzany: All these concepts that dominated science for half a century are falsified now), we read: Debunking the biggest genetic myth of the human tongue In 1940, the prominent geneticist Alfred Sturtevant published a paper saying the ability to roll one’s tongue is based on a dominant gene. In 1952, Philip Matlock disproved Sturtevant’s findings, demonstrating that seven out of 33 identical twins didn’t share their sibling’s gift. If rolling the tongue was genetic, then identical twins would share the trait. Sturtevant later acknowledged his mistake. But, of course, it stayed in the textbooks. Apparently, the skill can be taught to some people, but … This doesn’t mean tongue rolling has no Read More ›

… must’ve told a bud who seems to have put it up here: One thing the ENCODE consortium drove home is that DNA acts like a Dynamic Random Access memory for methylation marks. That is to say, even though the DNA sequence isn’t changed, like computer RAM which isn’t physically removed, it’s electronic state can be modified. The repetitive DNA acts like physical hardware so even if the repetitive sequences aren’t changed, they can still act as memory storage devices for regulatory information. ENCODE collects huge amounts of data on methylation marks during various stages of the cell. This is like trying to take a few snapshots of a computer memory to figure out how Windows 8 works. The complexity Read More ›

From: Evolution: The Fossils Speak, but Hardly with One Voice 5. Far too much attention may be given to genes and DNA. So much current evolution thinking, including questionable fields like evolutionary psychology, depends on the alleged power of the gene. Does anyone remember that fellow who said in the early 90s that a CD of your genome is “you”? Not even close. From the New Statesman: “According to a growing number of researchers, the standard story of the influence of genes is overblown. So many other factors influence how we turn out as individuals and how we evolve as a species that the fundamentals of biology need a rewrite.” “This is no storm in an academic tearoom,” a group Read More ›

Friends write to say that Darwinian evolutionary biologist (retired) William B. Provine has written a book , The “Random Genetic Drift” Fallacy (2014): Much of my life has been devoted to the history of population genetics. My early book was my Ph.D. thesis still in print: The Origins of Theoretical Populations Genetics (1971, 2nd edition, 1991). I stated in the 2nd edition in the Afterword that “random genetic drift” was giving me pause, as does the evolutionary synthesis. My later book was Sewall Wright and Evolutionary Biology (1986) and is also still in print. Now I am writing this book against “random genetic drift,” invented by R. A. Fisher and followed by Sewall Wright and J. B. S. Haldane. “Random Read More ›

And too few corresponding insights? Asks an op-ed in The Scientist : I just finished reviewing another mitochondrial genome paper. These days, the mitochondrial genome review requests are arriving faster than I can turn them out. Indeed, in 2014 alone, more than a thousand new mitochondrial genome sequences were deposited in GenBank—an almost 15 percent increase from the previous year. Few would question the utility of mitochondrial DNA (mtDNA) as a genetic marker. But it is increasingly clear that sequencing mtDNA has become an easy route to peer-reviewed publications; at times, the pursuit of these publications is encumbering journal editors, referees, and the research infrastructure as a whole. Is publishing papers on mitochondrial genomes a relic of the “publish or Read More ›

From ScienceDaily: A gene previously suspected of wielding the single greatest genetic influence on human obesity actually has nothing to do with body weight, according to a new study led by researchers at Harvard Medical School and Boston Children’s Hospital. The work not only overturns a major finding about the genetics of obesity but also provides the first effective ways to analyze “particularly ornery and confusing” parts of the genome, such as the locus of this gene, said the study’s co-senior author, Steven McCarroll, assistant professor of genetics at HMS. He analyzed genome-wide association data collected by the GIANT Consortium and found no association between AMY1 and body mass index, a measure of a person’s weight relative to their height. Read More ›

And textbook claims are incorrect, researcher says. From The Scientist : Mosaicism can result when a de novo mutation arises after an embryo is formed. Using newer, more sensitive sequencing technologies, researchers have recently begun to identify mosaic mutations. … Of these 107 mutations analyzed, seven (6.5 percent) were not detected in the parents’ germlines. … “Given the limitations of current sequencing technologies, this [frequency of mosaic mutations] may be just touching the tip of the iceberg,” said Philip Awadalla of the Ontario Institute for Cancer Research and the University of Toronto, who works on human population and medical genomics but was not involved in the current study. … “The textbook knowledge that our genome is identical in all the Read More ›

From Quanta Magazine: Genetically identical fruit flies raised under the same conditions are creating a biological map of what makes individuals unique. For scientists studying individual variation, one of the biggest open questions is why it exists. Is it helpful or harmful to the individual and the population? “We still know very little about the fitness consequences,” said Julia Saltz, a biologist at Rice University in Houston. Some versions of a gene might simply have bad quality control, pumping out a shoddy and inconsistent product. (Scientists refer to this as developmental instability and generally consider it harmful.) Alternatively, perhaps some variability makes for a stronger strain. “If you are more variable, a predator can’t guess what you are going to Read More ›

Should know better. In an article defending consensus science, physicist Ethan Siegel opines, Think about evolution, for example. Many people still rally against it, claiming that it’s impossible. Yet evolution was the consensus position that led to the discovery of genetics, and genetics itself was the consensus that allowed us to discover DNA, the “code” behind genetics, inherited traits and evolution. Actually, modern genetics started with Gregor Mendel who was as oblivious to Darwin’s work as Darwin was to his. The triumph of Darwinism has distorted genetics, such that horizontal gene transfer, epigenetics, and convergence were for many decades routinely underresearched. Scientists scrambled for evidence of the great wonders of accumulated information supposedly performed by Darwin’s natural selection acting on Read More ›

From ScienceDaily: When children are unmotivated at school, new research suggests their genes may be part of the equation. A study of more than 13,000 twins from six countries found that 40 to 50 percent of the differences in children’s motivation to learn could be explained by their genetic inheritance from their parents. The results surprised study co-author Stephen Petrill, who thought before the study that the twins’ shared environment — such as the family and teachers that they had in common — would be a larger factor than genetics. Instead, genetics and nonshared environment factors had the largest effect on learning motivation, whereas the shared environment had negligible impact. Talk about unbelievable burble. It must have been a happy Read More ›

Blow us away. No, really, from ScienceDaily: Scientists studied proteins found in cells, known as histones, which are not part of the genetic code, but act as spools around which DNA is wound. Histones are known to control whether or not genes are switched on. Researchers found that naturally occurring changes to these proteins, which affect how they control genes, can be sustained from one generation to the next and so influence which traits are passed on. The finding demonstrates for the first time that DNA is not solely responsible for how characteristics are inherited. It paves the way for research into how and when this method of inheritance occurs in nature, and if it is linked to particular traits Read More ›

They modulate gene expressions over cells’ lifetimes. From The Scientist : Not only do telomeres protect the ends of chromosomes, they also modulate gene expression over cells’ lifetimes. … New work led by Jerry W. Shay and Woodring Wright of the University of Texas Southwestern Medical Center in Dallas demonstrates that telomeres are more than just buffer zones. The team found that as chromosomes fold within the nucleus, telomeres come into contact with faraway genes and alter their expression. As telomeres shorten, which happens with aging, chromosome looping and gene-expression patterns change. “I’m delighted with this evidence that the [telomere] sequence may actually be doing some regulation and that the decrease of the sequence in some cells may drastically affect Read More ›

As in But what IS a gene? (At one time we knew. We were wrong. Honestly and stubbornly so). Philosopher (and photographer) Laszlo Bencze here: The notion of a gene seems to be becoming less and less useful with every discovery in genetics. Of course all (or practically all) of these discoveries are being made by strict evolutionists. They still palm off the increasing complexity of reproduction as the result of a long evolutionary process no matter how much their own work does not support that notion. The way I see it, the main purpose of the gene concept is to support a comprehensible evolutionary scenario. If one gene equals one protein and one protein equals one trait, it is Read More ›