All articles tagged with #leca
New geochemical data and molecular-clock analysis suggest life could have arisen during Earth's fiery Hadean period, about 4.4–4.2 billion years ago, with LUCA as the Last Universal Common Ancestor and LECA leading to modern eukaryotes; evidence points to liquid water despite extreme conditions, and ongoing genome recovery efforts may further refine when these ancestral stages appeared.
A comprehensive phylogenomic analysis shows Asgard archaea contributed the majority of core eukaryotic genes traced to LECA, with Alphaproteobacteria providing mainly mitochondrial-related components and energy metabolism; other bacteria contributed sporadically without clear patterns. This supports a model where key eukaryotic features—cytoskeleton and endomembrane system—evolved in the Asgard lineage before LECA, with mitochondria acquired later and additional bacterial genes entering gradually via HGT. The study uses soft-core pangenomes and constrained trees to minimize late HGT and test origins, though conclusions depend on the current sampling of Asgard and bacterial genomes.