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Quote: The coelacanth genome has also allowed scientists to test other long-debated questions. For example, coelacanths possess some features that look oddly similar to those seen only in animals that dwell on land, including “lobed” fins, which resemble the limbs of four-legged land animals (known as tetrapods). Another odd-looking group of fish known as lungfish possesses lobed fins, too. It is probable that one of the ancestral lobed-finned fish species gave rise to the first four-legged amphibious creatures to climb out of the water and up onto land, but until now, researchers could not determine which of the two was the likelier candidate. In addition to sequencing the full genome — nearly 3 billion “letters” of DNA — from the coelacanth, the researchers also looked at RNA content from the coelacanth (both the African and Indonesian species) and from the lungfish. This information allowed them to compare genes in use in the brain, kidneys, liver, spleen, and gut of lungfish with gene sets from coelacanths and 20 other vertebrate species. Their results suggested that tetrapods are more closely related to lungfish than to the coelacanth.