Rapid rates of biodiversity loss have supported the notion that Earth is experiencing a sixth major extinction event. The causes of worldwide biodiversity loss are multifaceted and context dependent. One of the most prominent groups experiencing population declines and extinctions are amphibians. Several pathogens and their associated diseases are especially...
Understanding the impact of mitochondrial dysfunction on genome evolution has the potential not only to provide new insights on the basic evolutionary processes influencing mitochondrial and nuclear genomes, but may also reveal novel avenues for evolutionary adaptive recovery from harmful mutations. Aberrant mitochondrial activity is fundamental to the pathology of...
Humans are increasing the scale and frequency of many natural disturbances, as well as adding novel disturbances to ecosystems. This thesis uses the arthropod community as a metric to examine the multi-trophic responses to disturbances in California grasslands. Chapter 2 explores how the long-term exclusion of native vertebrate herbivores has...
Disturbance has both direct and indirect ramifications that can influence species abundance, distribution, and ultimately the diversity found within a community. As a result, we might expect disturbance to play a particularly important role in the ability of non-native species to proliferate outside of their native range. In practice, disturbance...
The distributions of alkaline phosphatase, acid phosphatase,
non-specific esterases, and glycogen were described for the antennal
glands of the freshwater crayfish, Pacifastacus, and the marine crabs
Cancer and Pugettia.
Alkaline phosphatase is confined primarily to the luminal edge
of the labyrinth in all of the above forms whereas acid phosphatase...
Biological invasions provide a unique opportunity to study the mechanisms that regulate community composition and ecosystem function. Invasive species that are also ecosystem engineers can substantially alter physical features in an environment, and this can lead to cascading effects on the biological community. Aquatic-terrestrial interface ecosystems are excellent systems to...
Because many coral-reef fishes are observable in situ, are amenable to transplantation, have small home ranges and short generation times, they provide a excellent system to investigate many topics within general ecology, fisheries biology, and conservation biology. The primary goal of this dissertation was to use the coral-reef fishes system...
Although only a minority of introduced species become established and have noticeable consequences in their new communities, some can displace native species, alter food webs, and cause local extinctions. Studying these invasive species can provide new insights into basic ecological questions as well as inform management strategies. Pacific lionfish (Pterois...
The multifaceted role of the environment in regulating the structure and dynamics of biological communities has long fascinated ecologists and motivated much debate and research. Now, in a time of accelerated global changes due to human impacts, the need to understand how the environment shapes communities has gained new urgency....
Biological invasions have been identified as one of the prominent drivers of global environmental change. In particular, invasive predators typically have substantial negative effects on populations of native prey, even driving species to extinction in extreme cases. However, beyond direct predatory effects, little is understood regarding the specific mechanisms by...