Red alga “Chondrus crispus”, also known as pioka, collected off Roscoff in Morbihan. The first sequencing of the genome of a red alga was made on this alga about 20 cm long, very common on the rocky shores of the North Atlantic. Its genome has been shown to be small and compact for a multicellular organism. More than a billion years ago, red algae would have suffered, as a result of extreme environmental conditions, a massive loss of genetic material. Without this loss, red algae may have largely colonized the terrestrial environment in the same way as green algae. But red algae have been deprived of the necessary plasticity and genetic potential for it.