An Ancient Ecosystem
One of the ways the team determined the age of these trees was through genetic sequencing. They compared the mangroves of the San Pedro River to 79 trees in 11 sites along the peninsula. Their findings show that this population probably migrated from areas close to the modern-day coast while the area was still all saltwater. The mangroves aren’t the only trees that are relicts from the past: The genomes of nearly 100 other species of trees also showed signs of this origin story.
“This discovery is extraordinary,” Felipe Zapata, a biodiversity researcher at UCLA who led the genetic sequencing, said in the release. “Not only are the red mangroves here with their origins printed in their DNA, but the whole coastal lagoon ecosystem of the last interglacial has found refuge here.”
