Sharks May Not Form a True Family, New Genomic Study Suggests
A Yale-led study analyzed whole genomes from 48 shark-relatives and found conflicting signals: some DNA segments point to all sharks sharing a common ancestor, while others suggest species like frilled and cow sharks are closer to rays, implying sharks may not constitute a natural, exclusive group. The researchers estimate sharks emerged around 300 million years ago, offering new insights into early jawed vertebrate evolution; the study is awaiting publication.