The Sierra Nevada range towers over the Basin below, cutting the skyline with a jagged edge as far as the eye can see. Mountain ranges, like the Sierra Nevada, are symbolic of western North America and present barriers not only to most day hikers, but to many plants and animal too. For many alpine taxa, […]
The first steps in the process of speciation are a bit paradoxical when you think about it…how does one freely interbreeding species make the transition to two reproductively isolated, independent species? More specifically, how do intraspecific mating barriers become interspecific? And why even are there intraspecific mating barriers? Well, that last question is easier to […]
Adapting to temperature is critical for any organism. Thus, many mammals, especially small, temperature-sensitive ones, have adaptations allowing them to modulate their metabolisms to adapt to their local winter temperatures, at an energetic cost (Chappell, 1980; Garcia-Elfring, Barrett, & Millien, 2019; Geiser & Ruf, 1995). The optimal metabolic modulation could be very precise, and would […]
Taking a hike through the Villa Luz Natural Park in Southern Mexico, you’ll quickly find yourself enraptured. As you cross the steel bridge that hangs over the river, the lush, bright green foliage of the jungle and sounds of birds and howler monkeys surround you. The deeper you go, the faint sulfurous smell of rotten […]
Figuring out evolutionary relationships between species is hard enough when they diversified recently, but what if they rapidly diversified many millions of years ago? A group of baleen whales, the rorquals (Balaenopteridae), for example, diversified starting about 10.5 million years ago (Figure 1; Árnason et al. 2018). Within this group, the evolutionary relationship of the […]
Hybrid zones elucidate the barriers to interspecific reproduction, the raw material for speciation, and thus are unparalleled resources for evolutionary biologists (Harrison 1993). However, when hybrid zones appear to lack reproductive barriers to gene flow, they pose a different set of questions, for example, what are the historical and contemporary factors which facilitate gene flow […]
Humans are globally redistributing salt. Soils (Rengasamy 2006) and freshwater (Dugan et al. 2017) are becoming saltier, while the ocean is experiencing fresh and salty anomolies (European Space Agency 2019). In North America and other temperate zones, salt is commonly used to deice roadways and sidewalks. This makes life much safer for people, but when […]
In every biology textbook, Darwin’s finches remain a staple introduction to the concept of speciation and adaptive radiations. Considered part of the tanager family, these fifteen species native to the Galapagos Islands evolved from a single ancestor 2 million years ago (Lamichhaney et al. 2015). Since then, many examples of species flocks, or groups of […]
(feature image: The wild sunflower growing by the roadside. Credit: Matt Lavin from Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew.) Sabrina Heiser (@SabrinaHeiser) has written blog posts in Dr. Stacy Krueger-Hadfield’s Conservation Genetics and Science Communication courses at the University of Alabama at Birmingham. She is passionate about science communication, and, therefore, takes […]
Happy Darwin Day! It seems as auspicious a day as any to introduce myself. My name is Stacy Krueger-Hadfield and I am an assistant professor at the University of Alabama at Birmingham. I’m an evolutionary ecologist and the main theme of my research is the evolution of sex. To investigate this “paradox,” we use algae […]
