Modern Synthesis Review

The article "Perspective: Genetic Assimilation and a Possible Evolutionary Paradox: Can Macroevolution Sometimes Be So Fast As To Pass Us By?" by Pigliucci et al. delves into a fascinating concept: genetic assimilation. This process challenges our traditional understanding of evolution by suggesting that significant evolutionary change can occur surprisingly quickly, potentially escaping our observation. The Core Mechanism and its Controversial Past Genetic assimilation proposes that environmental pressures can induce epigenetic phenotypic changes in an organism. These changes, initially triggered by the environment, can become genetically encoded over generations. This means the organism evolves to express the previously environmentally induced trait even without the original environmental pressure. The authors delve into the historical acceptance and rejection of genetic assimilation within evolutionary biology. The concept was first proposed by C.H. Waddington...

The conventional understanding of evolution, encapsulated in the Modern Synthesis, posits that evolution proceeds through gradual changes in gene frequencies within a population. This framework primarily focuses on inherited DNA sequences as the sole basis for heritable traits. However, recent research, such as the compelling study "Gray wolves carry young pups over rugged terrain to track spring elk migration," presents a fascinating challenge to this established paradigm. This research not only reveals a remarkable and previously undocumented behavior in gray wolves but also hints at the involvement of a powerful, non-genetic mechanism: epigenetics. The findings of this article, when viewed through the lens of epigenetics, compel a re-evaluation of the Modern Synthesis and open new avenues for understanding adaptation and inheritance. The study itself is a testament to the wolves' incredible adaptability and parental devotion. Researchers observed gray wolf...

The modern synthesis of evolutionary biology, a framework that emerged in the mid-20th century, combined Darwinian natural selection with Mendelian genetics. It posits that evolution occurs primarily through changes in gene frequencies within populations, driven by forces like mutation, gene flow, genetic drift, and, most importantly, natural selection acting on a continuous range of small, heritable variations.  This model has had its successes, explaining an array of evolutionary phenomena, from the development of antibiotic resistance to the diversification of species over millions of years. However, the article "Rarity as double jeopardy" presents a compelling challenge to this established paradigm by highlighting a critical weakness in how the modern synthesis accounts for the persistence of rare traits and alleles, and the very existence of rare species. The central thesis of "Rarity as double jeopardy" is that rarity, in itself, is a significant ...