Dear MARMAM community, On behalf of all co-authors, we are excited to share our new publication exploring the evolutionary relationships of *Berardius *beaked whales. Abstract attached below! Morgan McCarthy morgan@sund.ku.dk Paper link: https://onlinelibrary.wiley.com/doi/10.1111/mec.70426 Abstract: Understanding the diversity of our oceans is fundamental now more than ever as climate change and human activities put increasing pressure on marine species and ecosystems. Beaked whales (family Ziphiidae) are among the most poorly understood marine mammals, in part due to their affinity to offshore underwater canyons and prolonged diving ability. The ziphiid genus *Berardius* is comprised of three extant species, however a lack of genomic data results in uncertainties of their evolutionary origin, phylogenetic relationships and the past environmental drivers of speciation and demographic fluctuations. Here, we analyze whole nuclear and mitochondrial genomes to better understand the evolutionary and demographic history of *Berardius *spp. Genome-wide comparisons support an initial divergence of *B. minimus* from the *B. bairdii *- *B. arnuxii* common ancestor ~ 4 million years ago (mya), and a divergence between *B. bairdii *and *B. arnuxii* ~ 1.5 mya. Despite these deep divergence times, gene flow was detected between species pairs for at least 75% of their post-divergence branch lengths. Strong levels of introgression (~8%) were detected between the non-sister but geographically overlapping *B. bairdii* and *B. minimus *species, despite their significant differences in body size. Our results show that the *Berardius* speciation process goes beyond simple bifurcating divergences. We hypothesize that resource specialization and an increased body size in the *B. bairdii* - *B. arnuxii* ancestor may have been an incipient driver of speciation, and further that climate cycles during the late Pleistocene, coupled with ranging movements to the tropics, could have permitted repeated opportunities for gene flow between species.