The body temperature of fish is the same as their environment. This means that a change in environmental temperatures, such as in the winter, results in a decrease in the physiological temperatures of fish. Such a change represents a significant challenge for temperate fish species, such as rainbow trout, that remain active in the winter as a decrease in temperature causes the heart to lose function.
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Freshwater habitats like the shield lakes of Northern Canada have experienced dramatic water chemistry changes over the last century due to human activities such as mining, farming and forestry. Acidification of these habitats has emerged as a major problem for freshwater organisms living in these habitats and depend on calcium. For example, Daphnia, small freshwater crustaceans have to rebuild their exoskeleton in a regular basis and require calcium to do so.
Predator-driven selection has been shown to cause the evolutionary change in prey populations. A newly published paper shows evidence that selection by a predatory crab may be responsible for ongoing speciation of the marine snail Littorina saxatilis. In Northern Spain L. saxatilis has evolved into two ecotypes (genetically distinct population within a species): crab-resistant and wave-resistant.
Previous studies led by Prof. Newmaster and colleagues in 2013 have estimated high levels of adulteration in North American herbal products resulting in investigations into some of the largest herbal supplements manufacturers in the nation. His lab continues to be a leading expert in this area of research and his students are highly sought after for their expertise in this field.
Many plant species depend on animals such as bees to transfer pollen from flower to flower. This dependence on bees is risky because they can consume pollen rather than transferring it to another flower. Plants can reduce this risk by limiting the amount of pollen deposited on each successive bee visitor.
Dr. Ryan Norris and his colleagues provide first evidence of the importance of male experience on the timing of breeding in female birds.
Female gray jays (Perisoreus Canadensis) can adjust their reproductive timing in response to variation in the environment through phenotypic plasticity (the ability of an individual to adjust behaviour in response to different environmental conditions).
Since the early twentieth century, multiple theories have been developed to explain variation in fish recruitment asserting alternative views regarding the importance of various biological and physical factors.
However, none of the recruitment hypotheses universally explains fish recruitment dynamics, and understanding the drivers of fish recruitment remains a major challenge in fisheries science today.
Modern evolutionary biology seeks to understand the genetic basis of adaptation and high-altitude environments provide an excellent system for studying how organisms cope with a multitude of stresses such as low levels of oxygen, low temperature, high levels of UV radiation, and strong seasonality.
The prevalence of mutualism nature, in which different species cooperate for common benefit, is difficult to explain. Theory conflicts on whether mutualisms should be stable or abandoned over evolutionary time. On the one hand, natural selection is expected to favour exploitation over cooperation because individuals that derive benefit from a mutualistic partner can maximize their own fitness by cheating, or otherwise avoiding the costs of cooperation.
It is well known that nutrient addition can lead to a loss in plant diversity, but a recent international study involving Dr. Andrew MacDougall has shed light on the fundamental mechanisms influencing biodiversity loss and plant species co-existence.