Even genes essential for life can be caught in an evolutionary arms race that forces them to change or be replaced.
Carpenter ants need endosymbiotic bacteria to guide the early development of their embryos. New work has reconstructed how this deep partnership evolved.
Recent major surveys show that reductions in genomic complexity — including the loss of key genes — have successfully shaped the evolution of life throughout history.
Studies suggest that epigenetics allows some learned adaptive responses to be passed down to new generations. The question is how.
Cells in symbiotic partnership, sometimes nested one within the other and functioning like organelles, can borrow from their host’s genes to complete their own metabolic pathways.
Some viruses can replicate without infecting any one cell with all their genes.
If highly repetitive gene-regulating sequences in DNA are easily lost, that may explain why some adaptations evolve quickly and repeatedly.