NeoDarwinian Review

Explanation of the article "Bet-hedging and variability in plant development: seed germination and beyond" by Abley et al. (2024), incorporating insights on how it challenges neo-Darwinism: Bet-Hedging as an Evolutionary Strategy in Plants The article explores the concept of bet-hedging developmental stochasticity in plants. This process introduces phenotypic variation (observable traits) in offspring despite their identical genes. This variability proves advantageous in unpredictable environments, prompting a reconsideration of the neo-Darwinian view of evolution, which traditionally emphasizes genetic mutations and natural selection as the sole drivers. The Power of Diversity: How Bet-Hedging Works Plants utilize bet-hedging as a strategy to ensure offspring survival in fluctuating environments . By producing offspring with diverse phenotypes , they increase the probability that some will possess traits best suited for the prevailing conditions....

Transposable elements (TEs), once dubbed “ junk DNA ,” are making a name for themselves as key players in the evolution of complex life. These mobile snippets of DNA can jump around genomes, potentially disrupting genes and causing instability. However, the relationship between TEs and their hosts is more nuanced than initially thought. The article "Impact of transposable elements on the evolution of complex living systems and their epigenetic control" explores this complex interplay. It highlights how TEs can both hinder and accelerate evolution, and how organisms have evolved mechanisms to control them. TEs: Double-Edged Swords for Evolution On the one hand, TEs can wreak havoc. When they insert themselves near or within genes, they can disrupt gene function or silence them altogether. Additionally, uncontrolled TE activity can lead to chromosome rearrangements, potentially causing mutations and harming the organism. On the other hand, TEs can also be sources...

The neutral theory of evolution proposes that evolutionary changes occur at the molecular level due to random mutations and genetic drift, rather than being driven by natural selection. This theory has been highly successful in explaining evolutionary patterns. However, the discovery of nonneutral synonymous duplications presents a challenge to its universality. Synonymous Duplications and the Neutral Theory Synonymous duplications are gene duplications where the copied gene (or exon) retains the same amino acid sequence as the original due to synonymous codons (different DNA sequences coding for the same amino acid). The neutral theory predicts that synonymous duplications are selectively neutral, meaning they don't provide an advantage or disadvantage and accumulate due to random chance. Nonneutral Synonymous Duplications Nonneutral synonymous duplications are synonymous duplications that can influence gene expression or protein function in unexpected way...

Explanation of the research article " Mapping epigenetic divergence in the massive radiation of Lake Malawi cichlid fishes " The study explores the fascinating evolutionary phenomenon exhibited by cichlid fish in Lake Malawi. These cichlids have undergone remarkable adaptive radiation , diversifying into hundreds of species with distinct physical features and ecological adaptations. Interestingly, this exceptional diversity occurs despite possessing highly similar DNA sequences . This research investigates the role of epigenetics, which can influence gene expression without altering the DNA code itself, in promoting this rapid evolution. Epigenetics and Phenotypic Diversity The researchers conducted a comparative analysis of genome-wide methylation patterns (methylome) and gene expression (transcriptome) in liver and muscle tissues of various cichlid species with distinct phenotypes. Their findings revealed substantial epigenetic divergence between these close...

The scientific article "Comparative analysis reveals distinctive epigenetic features of the human cerebellum" explores the epigenetic modifications in the cerebellum, a region of the brain crucial for motor control and cognitive function, across humans and other primates. Epigenetics refers to changes in gene expression that don't involve alterations in the DNA sequence itself. The study sheds light on the unique role of the cerebellum in human evolution. Traditionally, research on human brain evolution has focused on the prefrontal cortex , associated with higher-order thinking. This study investigates the cerebellum, which has recently gained attention for its contributions to complex functions like language . The researchers compared genome-wide methylation patterns in the cerebellum and prefrontal cortex of humans, chimpanzees, and rhesus macaques. Methylation is an epigenetic modification where a methyl group is added to DNA, inf...