Evolutionary History of the Proviruses HERV ‐K 113 and HERV ‐K 115

Abstract Human endogenous retroviruses are found throughout the genome, and most insertions predate human divergence from other primates. A small number are unique to humans and unfixed in the human genome. Much scientific interest has centered on the human endogenous retroviruses (HERV)‐K113 and HERV‐K115 insertions. The evolutionary history of these two endogenous proviruses is complex, and the estimates of both of their insertion times have recently been revised. HERV‐K113 inserted into the genome sometime between 0.8 and 1.3 million years ago (Ma), while HERV‐K115 was inserted into the genome sometime between 1.1 and 1.9 Ma. Both insertions occurred during a time when Homo erectus is believed to have been the dominant hominin species. Key Concepts: HERV‐K113 and HERV‐K115 are members of the HML‐2 group of endogenous retroviruses and neither insertion is fixed in the modern human genome. Despite their unfixed state, HERV‐K113 and HERV‐K115 are not recent insertions into the human genome. HERV‐K113 inserted into the genome sometime between 0.8 and 1.3 Ma. HERV‐K115 inserted into the genome sometime between 1.1 and 1.9 Ma. Despite a possibly wide separation in their insertion times, HERV‐K113 and HERV‐K115 are highly similar in sequence. Both insertions occurred during a time when Homo erectus is believed to have been the dominant hominin species.