Daniel Bolnick

How new species emerge has fascinated biologists since Darwin. Barriers to gene flow, such as sexual isolation, habitat selection, or postzygotic inviability, play critical roles. These lead to reproductive isolation and are crucial to the formation of new species. Written and edited by experts in the field, this collection from Cold Spring Harbor Perspectives in Biology reviews progress in our understanding of the speciation process. Recent advances have shed new light on how reproductive barriers are established, how these barriers to gene flow are coupled to each other, and the underlying genetic mechanisms. The contributors cover innovations in genetics, genomics, theoretical frameworks, and comparative techniques that have broadened the perspective of researchers in the field. They review the contributions of pre- and postzygotic isolating barriers, hybridization, chromosomal architecture, biotic and abiotic factors to speciation, particularly in cases of adaptive radiations. Speciation research has often become entangled with cultural and political views. This problematic history is also addressed, as is the impact of human activity on speciation. The volume will therefore be of interest not only to geneticists and evolutionary biologists but ecologists and other scientists interested in understanding how speciation occurs and its consequences.

The White Mountains of New Hampshire are home to many gushing, cascading waterfalls waiting to be discovered. This completely revised and updated edition of Waterfalls of the White Mountains outlines hiking trails ideal for observing the more than 100 waterfalls in the region, no matter experience level or ability. Each hike opens with the trail at a glance overview—including the distance, difficulty, altitude gain, and directions to the starting point. Helpful tips and suggestions are offered throughout, like the best times of year for each hike, best vantage points for viewing the falls, great swimming holes for cooling down, and uncrowded scenic treasures that are perfect for a woodland picnic. Also featuring labeled maps and fascinating short essays on local history and lore, Waterfalls of the White Mountains guides readers through their next excursion to the White Mountains of New Hampshire.