Scientists Decode Penguins’ Genome to Reveal Their Past—and Potential Future
Scientists have published the genomes of two species of penguins—the first of 16 types of penguins to have their DNA sequenced.
Adélie and emperor penguins have evolved to deal with harsh weather by being able to fast for months and regulate their body temperature. But the two species raise young in different places. Emperor penguins hatch their eggs on sea ice, using their feet to incubate the eggs, while Adélie penguins breed on the coastline in ice-free areas.
“We tend to think about penguins as being Antarctic animals, but there’s really only two of 16 species that breed in Antarctica,” said David Lambert, an evolutionary biologist at Griffith University in Queensland, Australia, and coauthor of the new genome report. The Galápagos penguin, for example, lives close to the equator.
The researchers estimate that penguins first appeared around 60 million years ago. Lambert said that the genome shows how the population of Adélie penguins grew but then went into a decline about 60,000 years ago during a glacial period— probably owing to a lack of ice-free places to hatch their young. At the same time, emperor penguin populations remained stable.
“Emperors penguins don’t really care: They nest on ice, so there are still a lot of ice areas there,” said Lambert.
But as sea ice decreases and temperatures rise because of climate change, the majestic emperors’ habitat will begin to disappear. Researchers predicted that emperor penguin populations will decrease by 50 percent by the end of the century, according to a study published last June in Nature Climate Change.
The genome also showed some areas of particular adaptation in genes that affected the thickness of skin, feathers, and forelimb development— not surprising, when looking at the environments in which penguins dive and live.
“Penguins do fly; they just happen to do it underwater—the principle is the same,” said Lambert. “The forelimbs are short but stout, which is exactly what is needed to travel at high speeds in the water.”
One of the forelimb genes, EVC2, has a human connection: Mutations of that gene cause Ellis–van Creveld syndrome, which is characterized by short-limbed dwarfism and short ribs.