Evolution of homology: From archetype towards a holistic concept of cell type

Abstract

The concept of homology lies in the heart of comparative biological science. The distinction between homology as structure and analogy as function has shaped the evolutionary paradigm for a century and formed the axis of comparative anatomy and embryology, which accept the identity of structure as a ground measure of relatedness.

Functional coherence among miRNA targets: a potential metric for assessing biological signal among target prediction methods in non-model species

“…Since most miRNAseq studies are also coupled with RNAseq, we further note that correlations between increased miRNA expression and decreases in putative mRNA target expression are also hypotheses fraught with a potential for high false-positives, given the diverse patterns of expression in such datasets coupled with generally few sets of diverse sampling points. Finally, while identified miRNA function in model species can certainly aid hypothesis formulation of miRNA impacts, such relies upon increasingly tenuous assumptions of evolutionarily conserved function (Rusin 2023).…”

Homologous vs. homocratic neurons: revisiting complex evolutionary trajectories

“…Ernst May summarized the century of evolutionary thinking: “After 1859, there has been only one definition of homologous than makes biological sense a feature [character, structure and so on] is homologous in two or more taxa if it can be traced back to [or derived from ] the same [a corresponding] feature in the presumptive common ancestor of these taxa” ( Mayr, 1982 ). Today, hypotheses of homology have been broadly applied to all levels of biological organizations, from genes, proteins, and organelles to organs and organ systems both in adult organisms and in development ( Wagner, 2014 ; 2016 ; DiFrisco et al, 2023a ; DiFrisco et al, 2023b ; Minelli, 2023 ; Rusin, 2023 ; Schlosser, 2023 ; Wanninger, 2024 ). However, many challenges exist at intermediate levels, especially for neuronal types and tissues, often associated with little-understood hierarchies of the so-called factorial concept of homologies ( Minelli and Fusco, 2013 ).…”

“…In other words, a single or a few molecular markers or modules cannot be an unbiased criterion for neuronal homologization. The modular nature of gene regulatory networks (Wagner, 2014;DiFrisco et al, 2023a;DiFrisco et al, 2023b;Rusin, 2023) and lineage-specific evolutionary changes (apomorphies and synapomorphies) are not yet incorporated in the quest to identify homologous neurons across taxa.…”

Can you tell me anything about homology? Any one thing that is new?

“…In the article “Evolution of homology: from archetype toward a holistic concept of cell types” Leonid Yu. Rusin considers the technical advancements in comparative molecular evolutionary biology, specifically the recent progress in high‐throughput single‐cell RNA sequencing (Rusin, 2023). According to Rusin, these techniques allow to identify cell types based on a core regulatory network, a set of interacting transcription factors.…”