Epigenetic Lamarck

The “histone code” is a hypothesis which states that DNA transcription is largely regulated by post-translational modifications to these histone proteins . Through these mechanisms, a person's phenotype can change without changing their underlying genetic makeup, controlling gene expression. The histone code hypothesis represents a significant layer of complexity in our understanding of gene regulation, moving beyond the traditional gene-centric view of neo-Darwinism. While neo-Darwinism primarily focuses on changes in DNA sequence as the driving force behind evolution, the histone code highlights the crucial role of epigenetic modifications in shaping gene expression and, potentially, influencing phenotypic outcomes. Histones are proteins that package and organize DNA into structures called nucleosomes , the fundamental units of chromatin.  These nucleosomes, and the histone proteins within them, are subject to a variety of chemical modifications, inclu...

The journal article "Can epigenetics translate environmental cues into phenotypes?" by Norouzitallab et al. (2019) delves into the fascinating interplay between environmental stimuli and phenotypic expression, mediated by epigenetic mechanisms. This comprehensive review explores how epigenetic modifications, such as DNA methylation and histone modifications, act as a bridge between the environment and an organism's traits, shaping its development, physiology, and even evolutionary trajectory. Key Concepts Explored in the Article Environmental Sensitivity of the Epigenome: The article emphasizes the dynamic nature of the epigenome, highlighting its susceptibility to a wide array of environmental cues, including nutrition, stress, toxins, and social interactions.  These environmental factors can induce epigenetic modifications that alter gene expression patterns, leading to phenotypic variations. Epigenetics as a Mediator of Phenotypic Plasticity: Phenotypic ...

The traditional narrative of evolution, heavily reliant on random genetic mutations and natural selection, has served us well for over a century. However, the rise of epigenetics offers a compelling, and competing, perspective, suggesting that heritable changes can occur independently of DNA sequence alterations. These changes, often triggered by environmental factors, introduce a new layer of complexity to the evolutionary process, potentially reshaping our understanding of adaptation, inheritance, and the very nature of evolutionary change. Epigenetics encompasses a suite of molecular mechanisms that modulate gene expression without altering the underlying DNA code. These mechanisms include DNA methylation, histone modifications, and the action of non-coding RNAs. DNA methylation, the addition of methyl groups to DNA, can silence genes, while histone modifications, chemical changes to the proteins around which DNA is wrapped, can alter gene accessibility. Non-coding RNAs...