Researchers made the find using an algorithm that purportedly distinguishes between mutations that were selected for and those that came along for the ride by coincidence, a feat that has long eluded scientists.
Immunoglobulin genes might have evolved much earlier than previously expected, perhaps even in the common ancestor of Cnidarians and Bilateria, a study suggests.
The genomes of living animals are littered with DNA from long-gone relatives, providing a lens on evolution, past extinctions, and perhaps even solutions to agricultural problems.
Mammals that give birth to live young may have evolved to make use of the remnants of viruses in their genomes to ward off pathogens, a study suggests.