Answer:
it can result in fish kills and restrictions on human consumption it can change the physiology of fish it can cause long-term alterations of aquatic ecosystems
Explanation:
Species evolve independently possibly due to geographical isolations or behavioural isolations.
Geographical isolation includes the isolation of 2 groups of the same species. Since these 2 groups live in different locations, (e.g. a volcanic eruption resulting in a barrier between one side of an ocean and another side of the ocean), they will have different selection pressures in their different environments as well (e.g. one side of the ocean may have more sunlight and thus more underwater plantations than the other side of the ocean). Natural selection will eliminate those with disadvantageous characteristics (e.g. Fishes that only eat plants and nothing else on the side of the ocean with little plantations) with unfavourable alleles, and select for those with advantageous characteristics (e.g. Fishes are able to eat plants and other organic substances as well on the side of the ocean with little plantations) with favourable alleles.
Since the 2 groups have different selection pressures, natural selection will occur in different ways, selecting for and against different types of fishes with different types of alleles. Also, because of the barrier, they are not able to mate with each other, and there are no mixing of genes from one side of the ocean and the other side. They are genetically isolated. As genetic drift occurs over time, their gene pools become different from each other. Thus, they evolve independently.
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Hydropower can be harnessed from flowing and falling water. Water stored behind dams and at a height has a lot of potential energy which is converted into mechanical and electrical energy.This water is released gradually and is made to fall under the force of gravity and drive hydraulic turbines and electrical generators.
Hydropower is also another indirect form of using solar energy. Hydropower has great potential as a supplier of electricity but environmental constraints limit such a development as the generation of electricity by hydroelectric power plants result in pollution and massive ecological disruptions such as land flooding, siltation, eutrophication and adverse effects on flora and fauna.
Smaller dams and reservoirs cause less damage but cannot exploit the full potential of this energy resource. Planning environmental impact assessment and construction of a hydroelectric power plant takes many years and the high initial capital investments are also limiting factors in the development of hydropower.
The development cost of hydroelectric power plants can be reduced by developing low cost turbines and generators, involving public participation in the development and operation of the project and using efficient environmental friendly technologies.
Bonds between the strands are relatively weak hydrogen bonds, whereas bonds within the strands are relatively strong covalent bonds.
