NeoDarwinian Review

Horizontal gene transfer (HGT) is the movement of genetic material between organisms that are not related by descent. This process can occur between different species of bacteria, and even between bacteria and eukaryotes. HGT has been shown to play a significant role in the evolution of bacterial genomes, and it is thought to be responsible for the spread of antibiotic resistance genes and other virulence factors. Ultraconserved elements (UCEs) are stretches of DNA that are highly conserved across different species. These elements are typically found in non-coding regions of the genome, and they are thought to play a role in gene regulation. UCEs have been used to study the evolutionary relationships between different species, and they have also been used to develop molecular markers for phylogenetic studies. Recent research has shown that HGT can play a role in the movement of UCEs between different species. This finding has important implications for our understanding of ...

Ultraconserved elements (UCEs) are stretches of DNA that are highly conserved across species, making them valuable markers for phylogenetic studies. However, despite their high conservation, UCEs can still exhibit gene tree discordance, where the evolutionary history of a particular UCE differs from the overall species tree. Recent research has identified incomplete lineage sorting (ILS) as a major contributor to this discordance. Understanding Incomplete Lineage Sorting ILS occurs when ancestral genetic polymorphisms persist through multiple speciation events. This means that different alleles of a gene may be inherited by different descendant species in a way that does not reflect the true species relationships. Imagine a population with two alleles for a particular gene, 'A' and 'B'. If this population splits into two species, it's possible that one species might inherit only allele 'A' while the other inherits only allele 'B'. This ca...

  The 2024 Nobel Prize in Physiology or Medicine was awarded to Victor Ambros and Gary Ruvkun for their groundbreaking discovery of microRNA and its role in post-transcriptional gene regulation. This award is a testament to the importance of basic research and the profound impact that seemingly small discoveries can have on our understanding of life and disease. What are microRNAs? MicroRNAs are short, non-coding RNA molecules that regulate gene expression. They bind to messenger RNA (mRNA) molecules, preventing them from being translated into proteins. This process can fine-tune the production of proteins in a cell, influencing a wide range of biological processes, including development, differentiation, and cell death. Why is the discovery of microRNAs so significant? The discovery of microRNAs has revolutionized our understanding of gene regulation. Before this discovery, it was thought that gene expression was primarily controlled at the level of transcription (th...

"When thinking about genetics, we often think of lineages and the passing down of genes through generations. We think about (neo darwinian] vertical transmission. However, bacteria also acquire genetic material through horizontal transmission (HGT). The human body is a complex biological network comprising ten microbes for each human cell and 100 microbial genes for each unique human gene". Understanding bacterial networks of gene exchange is thus essential for an understanding of ourselves." Gilbert, Nature When thinking about genetics, we often focus on the concept of lineages and the vertical transmission of genes from one generation to the next. This neo-Darwinian view emphasizes the inheritance of genetic traits from parents to offspring. However, there's another fascinating aspect of genetics that often gets overlooked: horizontal gene transfer (HGT). This process, prevalent in bacteria, involves the acquisition of genetic material from unrelated or...

Redo of a Famous Experiment on the Origins of Life Reveals Critical Detail Missed for Decades: The Effect of Glass and Teflon In the quest to understand the origins of life on Earth, the Miller-Urey experiment holds a legendary status. Conducted in 1952 by Stanley Miller and Harold Urey, this groundbreaking experiment simulated the conditions believed to exist on early Earth, demonstrating that simple organic molecules, the building blocks of life, could be formed from inorganic precursors. However, a recent re-examination of this classic experiment has revealed a critical detail overlooked for decades – the significant influence of the experimental apparatus itself on the results. The original Miller-Urey experiment involved a closed system of glass flasks containing water, methane, ammonia, and hydrogen – gases thought to dominate the early Earth's atmosphere. Electric sparks were passed through the mixture to simulate lightning, a potential energy source for the for...

“The waiting time for a pair of pre-specified mutations was calculated by Durrett and Schmidt, using a Drosophila mutation that inactivates a transcription factor as their model. Their results, which are strongly dependent on assumptions about nucleotide mutation rate, population, and neutrality of mutations, show that the second specific mutation appears after 9 million years .” De novo gene birth is the process where new genes arise from previously non-coding DNA sequences. These "newborn" genes can code for proteins or function as RNA genes. The exact mechanisms are unclear, but they may involve mutations that create open reading frames (ORFs) or transcriptional activation. This process contributes to genetic novelty and can play a role in and adaptation. Here are 10 ways in which de novo gene birth by Neo-Darwinism is improbable: De novo gene birth requires a large number of mutations to occur in a specific order. This is because a new gene must be created f...

The article "Epigenetics and Epidemiology of Lactase Persistence" discusses Lactase persistence, the ability to digest the milk sugar lactose throughout adulthood, is a fascinating example of human adaptation. While most mammals lose the ability to produce lactase, the enzyme responsible for breaking down lactose, after weaning, a significant portion of the human population retains this ability. This trait has a complex interplay of genetic and environmental factors, with epigenetics playing a crucial role in its regulation. The Genetics of Lactase Persistence The ability to digest lactose is primarily determined by the lactase gene (LCT), which codes for the lactase enzyme. Lactase persistence is associated with specific genetic variants, most notably single nucleotide polymorphisms (SNPs) located in a regulatory region upstream of the LCT gene. These SNPs influence the expression of the LCT gene, ensuring continued lactase production into adulthood. Epigenetic...