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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 explains that uniparental inheritance, where mitochondria are inherited from only one parent, increases variance between daughter cells. This evolutionary strategy minimizes errors by ensuring that only one parent passes on mitochondria, which is crucial for maintaining genetic stability.

Nick Lane discusses how uniparental inheritance of mitochondria increases genetic variance between cells, allowing natural selection to favor those with fewer mutations.

The difficulty of successful endosymbiosis, where one cell engulfs another, is a significant barrier to complexity. While this may have occurred many times, it often fails, leading to the loss of the endosymbiont.

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.

Bacterial evolution is fascinating because they maintain small genomes but have access to a large pan genome. For example, an E. coli cell might have 3,000 to 4,000 genes but access to 30,000 to 40,000 genes. This allows them to adapt by borrowing genes from other strains, which is crucial for survival in different environments.

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.