Climate change affects many organisms in varying ways. Organisms that are unlikely to migrate must adapt to climate change through evolutionary responses. Numerous studies have documented evolutionary responses to climate change over a period of one to three decades. However, the study by Kingsolver and Buckley (2015) provides evidence of a delayed evolutionary response to climate change for the subalpine and alpine butterfly, Colias meadii, in the southern Rocky Mountains of Colorado. Kingsolver and Buckley investigated the evolution of wing melanin of C. meadii and its effect on selection. They state that many species of the study area have adapted to their local climate conditions and “have limited potential for large-scale migration and gene flow.” Continue reading →
Climate change affects many organisms in varying ways. Organisms that are unlikely to migrate must adapt to climate change through evolutionary responses. Numerous studies have documented evolutionary responses to climate change over a period of one to three decades. However, the study by Kingsolver and Buckley (2015) provides evidence of a delayed evolutionary response to climate change for the subalpine and alpine butterfly, Colias meadii, in the southern Rocky Mountains of Colorado. Kingsolver and Buckley investigated the evolution of wing melanin of C. meadii and its effect on selection. They state that many species of the study area have adapted to their local climate conditions and “have limited potential for large-scale migration and gene flow.” Comparing wing melanin to regional climate change, the authors relied on models to predict selection and evolutionary responses over the past 50—60 years. Continue reading →
Greenland white-fronted geese, Anser albifrons flavirostris, spend their winters in Ireland, stage and refuel in Iceland, and breed in Greenland. Because climate change has advanced the spring thaw in Ireland by about 18 days since 1985, these geese have more food to eat and are departing for and arriving in Iceland earlier than previous years. However, climate change has not caused a significant change in the temperatures of Icelandic staging areas and therefore has not caused a significant change in the departure time from Iceland to Greenland, thus the geese are staying in Iceland for a longer period of time than in previous years and arriving at their breeding grounds around the same time as historically known. Fox et al. (2014) used an abdominal profile index (API) as an indicator of fat stores in geese to determine if the amount of stored fat was the cause of advanced departure to Iceland. The authors also considered trends in temperature as indicators of departure time, but found that, because of the migration distances from Ireland to Iceland and Iceland to Greenland, temperatures are “very poor predictors” for departure times; meaning that the geese would not be able to use the temperature in Ireland to predict the temperature in Iceland nor the temperature in Iceland to predict the temperature in Greenland. Compared to previous studies, Fox et al. found that the Greenland white-fronted geese departed Ireland 33 days earlier in 2012 than they did in 1969 and arrived in Iceland 22 days earlier in 2012 than they did in 1997. The authors also note that the mean API at departure from Ireland in 2012 and 2013 increased significantly from previous years. Continue reading →
Ectotherms are organisms that rely on environmental heat sources to maintain their body temperatures. The timing of reproduction in these organisms has much to do with their available thermal time windows. According to Van Dyck et al. (2015), the warming climate could cause an increase in the annual number of generations of ectotherms, but this response is potentially maladaptive, leading to a developmental trap; if an organism reproduces at the end of its reproductive season, there is a good chance that the new generation will die and the energy used to produce that generation would have been in vain. Continue reading →
From 2006 to 2012, Michael Benard conducted research at a field station in southeastern Michigan where he used drift fences and pitfall traps to capture both adult and metamorphosing wood frogs (Rana sylvatica) at six wetlands (Benard 2014). Benard’s goal was to determine if a relationship exists between date of breeding and winter temperature and precipitation, and between the female reproductive rate (fecundity) and winter temperature and precipitation. Using these data, he was also able to discern if breeding dates affect changes in metamorphosis timing, length of the larval period, weight at metamorphosis, and larval survival. Continue reading →
Our newest book, published on May 6, 2015 and available at Amazon.com for $19.95.
The focus of this book is the interactions between energy, ecology, and climate change, as well as a few of the responses of humanity to these interactions. It is not a textbook, but a series of chapters discussing subtopics in which the authors were interested and wished to write about. The basic material is cutting-edge science; technical journal articles published within the last year, selected for their relevance and interest. Each author selected eight or so technical papers representing his or her view of the most interesting current research in the field, and wrote summaries of them in a journalistic style that is free of scientific jargon and understandable by lay readers. This is the sort of science writing that you might encounter in the New York Times, but concentrated in a way intended to give as broad an overview of the chapter topics as possible. None of this research will appear in textbooks for a few years, so there are not many ways that readers without access to a university library can get access to this information.
This book is intended be browsed—choose a chapter topic you like and read the individual sections in any order; each is intended to be largely stand-alone. Reading all of them will give you considerable insight into what climate scientists concerned with energy, ecology, and human effects are up to, and the challenges they face in understanding one of the most disruptive—if not very rapid—event in human history; anthropogenic climate change. The Table of Contents follows: Continue reading →
Much research has been conducted on phenological reproductive responses to climate change. These responses occur commonly in plants, butterflies, birds, amphibians, fish, and insect larvae. Because sea turtles use thermal cues to begin migration to nesting sites, the authors hypothesized that leatherback turtles (Dermochelys coriacea) are delaying nesting in response to increased temperatures at their foraging grounds (Neeman et al. 2015). Biological responses due to increased temperatures have been observed in many other species of sea turtles. Some of these effects include offset sex ratios in embryos, nesting scarcity, reduced clutch size, and increased mortality rates of eggs and hatchlings. Continue reading →
Surveying 85 unique sites on the western borders of North Carolina and Virginia, biologist Nicholas Caruso and his team collected data on adult specimens of Appalachian woodland salamanders (genus Plethodon). The results showed a reduction in salamander body size in accordance with lower climate temperatures. Because woodland salamanders are lungless they breathe through their skin and require a moist environment for survival. The authors used historical and present-day data to model the changes in body size of 15 species of salamanders over the past 55 years. The dataset included 9,450 adult body size measurements from 102 populations of the 15 different species of salamanders. An 8% reduction in the average salamander size was found in all of the species over the 55-year study (Caruso et al, 2014). The reduction in body size reveals the plasticity of organisms to adapt to changes in climate. Because body size is directly linked to diet and foraging behavior, growth rates are also affected. Smaller body size means less surface area, and less loss of moisture through cutaneous responses. Also, the salamanders that were surveyed have demonstrated an increase in metabolism. Continue reading →