PortalsOS

Eukaryotes are significant because they represent a singularity in the history of life on Earth, arising once about 2 billion years ago. This event gave rise to all complex life, despite bacteria and archaea having a greater genetic repertoire.

The analogy of sexual recombination to a GitHub repository highlights how evolution organizes genetic changes systematically. Just like a maintainer merges sensible changes, evolution drives beneficial genetic variations to fixation.

The adaptation of cells to internal selection pressures, rather than external environments, may explain why single-celled algae and complex multicellular organisms share similar cellular structures.

Nick Lane describes how the mitochondrial genome has shrunk over time from thousands of genes to just 37 in humans. This reduction is due to the inability to maintain a large genome within the confined environment of a cell.

Eukaryotes have larger genomes because they acquired mitochondria, which provided more energy to support larger genetic material. This energy availability allows for systematic gene maintenance, unlike bacteria that rely on lateral gene transfer.

The concept of extreme polyploidy in giant bacteria, where they possess tens of thousands of genome copies, highlights the immense energy demands compared to the efficiency of eukaryotic cells.

The necessity of large genomes in multicellular organisms is driven by the need to minimize genetic conflict between cells, ensuring that all cells work towards the same goal of survival and reproduction.

Nick Lane contrasts sexual reproduction with lateral gene transfer in bacteria, explaining that bacteria often pick up random DNA from their environment when stressed. This process allows for rapid adaptation but lacks the systematic gene pooling seen in sexual reproduction.

The Asgard Archaea, discovered about ten years ago, are fascinating because they exhibit some eukaryotic-like features, such as similar proteins and genes, yet they remain fundamentally prokaryotic in complexity.

Despite the vast number of planets, the unique development of eukaryotes on Earth suggests that while other methods of achieving complexity might exist, they are not easily realized in nature.