Large populations have many ecological, behavioral, and physiological mechanisms that prevent hybridization, the production of offspring among genetically distant taxa, whether they be individuals of different species, or individuals of the same species but with different adaptations (the latter being intraspecific hybridization). As with inbreeding depression, these mechanisms may fail in small populations, leading to …
Mating among closely related individuals, which occurs in small populations, often results in lower reproductivesuccess and weaker offspring. In large populations, a variety of instinctive mechanisms are in place to promote heterosis, which occurs whenoffspring have a level of genetic variation that improves their individual evolutionary fitness. Some species are predisposed to disperse from their …
Thermal pollution describes localized human-induced temperature changes in the natural world. Aquatic ecosystems represent one of the ecosystems most vulnerable to thermal pollution. For example, when water is released from big dams, it comes from the colder middle and lower strata of the reservoir, leading to rapid cooling of aquatic ecosystems further downstream. The opposite …
Many people find a sense of freedom when they are in natural surroundings, with peace and quiet facilitating a much-needed connection to nature. These experiences are increasingly being threatened by noise pollution. Noise Pollution and Its Sources; noise pollution (also called acoustic pollution)—caused by human activities, such as industrial, military, and transportation systems—is harmful and …
Light pollution describes the addition of excessive, prolonged, or poorly designed artificial light to the natural world. As a consequence of an increasingly industrialized world, light pollution has increased dramatically over the past decades as more people have gained greater access to electricity. Behavioral disruption is perhaps the most well-known consequence of increased light pollution—consider …
Soil pollution occurs when the soil encounters foreign chemicals and other pollutants. This type of pollution is often associated with industrial activities that extract agricultural and land resources, runoff, pesticide use, oil spills, acid rain, improper sewage treatment, and improper waste disposal. People and wildlife can therefore become ill through direct contact with contaminated soils, …
Air pollution by hydrocarbons often manifests itself in the form of photochemical smog. Hanging like a thick cloud over industrial areas, people sometimes confuse it with natural mist in the early morning. In the past, people and industries believed that the atmosphere was so vast that it contained gases or particles released into the air, …
Water pollution, the accidental or intentional dumping of pesticides; herbicides; oil products; fertilizers; sewage; industrial waste; detergents; and other foreign chemicals and objects into aquatic environments is arguably the biggest current pollution concern. Biomagnification The dumping of products containing heavy metals into aquatic environments is particularly concerning because heavy metals are toxic even in small …
The Definition of Water Pollution; Water pollution effects and causes Read More »
Pollution does not always lead to immediate mortality but instead can have sublethal impacts that compromise organisms’ fitness over time, with population declines as the end result. Many pollutants take many years to biodegrade and thus continue to pose a threat to wildlife and humans long after entering the environment. Rachel Carson’s 1962 book Silent …
Generalist species with high genetic diversity and rapid reproduction are likely to benefit from climate change. Many species that exhibit these characteristics are carriers of agricultural pests and diseases. To be clear, not all species will suffer equally from climate change. Indeed, there are species that will be resilient and others that will even benefit …
