Eco-Devo-Toxo

           A common theme in this course has been the discussion of different contaminants and how they enter and persist in natural systems. Identifying the levels at which these contaminants are entering the food web and their method of transport are crucial to assessing their risk. As we discussed this topic in class I was reminded of a paper I read during my Freshwater Ecosystems course and am very glad I went back and re-read it. Published in Ecological Applications, the authors Walters et. al demonstrated how PCB's are transported from aquatic systems into terrestrial food webs through the capture and consumption of aquatic insects by Spiders  and Herps. I thought this particularly appropriate for our classes interests.      One of the largest challenges in a study like this is to determine where the selected predators are obtaining most of their food from. To do this, the authors used a stable isotope analysis to identify the...

One aspect of plasticity that interests me is the idea of compensatory growth (CG). CG is when limitation in resources restricts something like a tadpole from growing at an early stage, but then later, a release in that restriction results in an accelerated growth rate above the average in a population. Observationally, this may just look like less fit tadpoles. Bigger is always better, right?   Maybe not. Consider an extreme example, where a large spider has caught two types of prey on its web, a fruit fly, and a housefly. Now suppose the spider can only pick one prey (perhaps they're only loosely caught on the web and there's a short window of opportunity). Which will the large spider most likely go for? It will probably choose the larger housefly.  Similarly, think of two tadpoles. This time they're the same species, but one is larger than the other. A giant ambushing Anax larva also lives in this pond and it's hungry. But it will give away its position when it attac...

Over the course of the past few weeks I've been fascinated by extreme life cycles and had planned on writing about the development of organisms that possessed some of those life cycles. I stumbled upon a few examples of parasites that had complex multi-host lifecycles which perked my interest and also was something we hadn't dwelled on in class. We've touched briefly on in utero development which I suppose is somewhat like a parasite developing in a host, but parasite development hasn't been covered. Furthermore, is parasite development subject to similar environmental stressors as the ones we've discussed?  In a paper (cited below) by Logan A. et al., the authors want to know if pollen starvation (low food abundance) in hosts can alter parasite abundance in hosts.  The researchers did an experiment involving  Crithidia bombi (gut parasite) in bumble bees. In this experiment, the researchers were curious about how pollen starvation effects parasite abundance in host...

 Biologists at Plymouth university have been working in conjunction with pharmaceutical company AstraZeneca to examine the effectiveness of new 'virtual-fish' as model organisms. It is hoped that the cultured 'fish' could help test for toxicity and concentration of manmade chemicals.  This heading caught my eye, especially since many of the papers read in our course relied on live amphibians or other organisms to examine the impacts of pollution, bioaccumulation, or (with less mortality) factors like the impacts of clutch density. Model organisms are a crucial aspect of applicable research- they allow us to generalize results across species and develop baselines for testing. They also mature quickly, which is beneficial for timely research. Could this all be changing?  The university has developed a method for removing cells from the liver of rainbow trout, and manipulating them into a 3-dimensional spheroid, which behaves much like natural animal tissue. These cell sph...

 Throughout our class we have obviously been talking about phenotypic plasticity within the animal kingdom, but what about plants!? Plants are incredibly divers and have covered virtually every inch of the world's surface (with some really cold exceptions). I started to wonder about phenotypic plasticity in plants. I remembered back in my dendrology class how leaves at the base of a tree will be more etiolated (elongation of leaves / stems) than leaves in the canopy to better collect sunlight in a shaded environment. This caused me to dig into the literature of plant plasticity. Surprisingly, carnivorous plants of the North American genus Sarracenia is at the center of this research. Just like how amphibians are often used to describe plasticity because of their "two-life" strategy, so are carnivorous plants. Sarracenia  compensates for living in N poor soils by trapping inverts, however these plants still need and use their modified leaves (hoods) for photosynthesis.  ...

Throughout this course, we have frequently discussed how early life conditions can influence an organism later on in life. We have discussed this in a variety of different contexts, but one aspect we haven’t really touched on is disease risk. I have always been interested in how exposure to stressors in formative life stages of development may have enduring health effects. We have discussed how early-life stressors can alter an organism’s behavior later on in life. This altered behavior may have an impact on an organism’s ability to avoid infection, and in turn, increases their infection risk and/or tolerance. This is just one potential mechanism by which early-life exposure to stressors may influence disease risk later on in life.   A paper published in 2013 by Jason Rohr and colleagues entitled “Early-life exposure to a herbicide has enduring effects on pathogen-induced mortality” briefly discusses a variety of potential mechanisms by which early-life exposure to stressors ma...