Genetics

I’ve been saying the OP’s title for years now. And, every day, I read review articles in the like of Phys.Org (they usually get out the articles first!) and, sure enough, there’s an article undermining Darwinian orthodoxy and the neo-Darwinian mechanisms that underpin it. Here’s today’s latest. It involves the insect genome and proteins once considered indispensible, hence ‘conserved’, throughout all eukaryotic lineages: Cell division, the process that ensures equal transmission of genetic information to daughter cells, has been fundamentally conserved for over a billion years of evolution. Considering its ubiquity and essentiality, it is expected that proteins that carry out cell division would also be highly conserved. Challenging this assumption, scientists from Fred Hutchinson Cancer Research Center have found Read More ›

Here’s a news article from Phys.Org on a lamprey study. Actually it’s a study concerning phylogenetics and using gene regulatory mechanisms to figure out the relationships that exist. It turns out that in the lamprey, which is part of the Cambrian explosion, the same kind of hind brain gene regulatory mechanisms are in place as in “jawed” vertebrates, including mammals. From the article: The team at Stowers, collaborating with Marianne Bronner, Ph.D., professor of biology at Caltech, focused on the sea lamprey because the fossil record shows that its ancestors emerged from Cambrian silt approximately 500 million years ago, 100 million years before jawed fish ever swam onto the scene. The question was, could the hindbrain gene regulatory network that Read More ›

Mutations are used to explain evolution but also cause cancer. Biologists have discovered conditions for multiple mutations. Can we therefore infer that evolution via mutations is more likely? or that enhanced mutations will cause faster species degradation and extinction?

Biologists describe mechanism promoting multiple DNA mutations

DNA mutations—long known to fuel cancer as well as evolutionary changes in a living organism—had been thought to be rare events that occur randomly throughout the genome.

However, recent studies have shown that cancer development frequently involves the formation of multiple mutations that arise simultaneously and in close proximity to each other. . . .Anna Malkova, associate professor of biology in the UI College of Liberal Arts and Sciences, notes that the DNA repair pathway, known as break-induced replication (BIR), can promote clusters of DNA mutations.

“Previously, we have shown that double-strand DNA breaks, which can result from oxidation, ionizing radiation and replication errors, can be repaired by BIR,” says Malkova.

“During BIR, one broken DNA end is paired with an identical DNA sequence on another chromosome and initiates an unusual type of replication, which proceeds as a migrating bubble and is associated with the accumulation of large amounts of single-strand DNA,” she says.

In the Cell Reports study, researchers subjected yeast cells undergoing BIR to alkylating (cancer cell-killing agents) damage. “We found that the single-stranded DNA regions that accumulate during BIR are susceptible to damage that leads to the formation of mutation clusters,” explains Cynthia Sakofsky, postdoctoral fellow at the UI and one of two co-first authors on the paper. “These clusters are similar to those found in human cancer,” she says.

Importantly, say the researchers, the paper provides a mechanism to potentially explain how genetic changes form in human cancers. Thus, it will be critical for future research to determine whether BIR can form clustered mutations that lead to cancer in humans.

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