Dengue is a serious viral disease that is typically spread by a mosquito called Aedes aegypti. The spread of dengue could be controlled by reducing Aedes aegypti populations. A biotechnology company has devised a way to achieve that: it has created a genetically modified (GM) Aedes aegypti mosquito. When the GM mosquitoes reproduce with wild mosquitoes, the mosquitoes in the next generation are defective and cannot survive. Releasing the GM mosquitoes to the wild would therefore reduce the population of Aedes aegypti and limit the spread of dengue.
However, there are critics who believe that the plan to release the GM mosquitoes is potentially very dangerous and should not be put into practice.
Other Mosquitoes May Increase
First, the Aedes aegypti mosquito is not the only mosquito that can spread dengue. Other, rarer mosquito species carry even more powerful versions of the dengue virus. The critics suggest that if the Aedes aegypti population is reduced, populations of other mosquitoes could increase to take their place and then would spread more dangerous forms of the virus.
GM Mosquito Bite Could Be Dangerous
Second, the critics are concerned about what might happen when the GM mosquitoes bite people. The mosquitoes are genetically engineered to produce a defective protein—that is why their offspring die. If the defective proteins are passed to people when the GM mosquitoes bite them, we do not know what the effects might be.
Unforeseen Ecological Effects
Third, there are concerns that introducing any genetically modified organism into an ecosystem might have unforeseen negative consequences. There are examples of this: the population of one type of butterfly was reduced by half after GM crops were introduced in areas where it lives. Introducing GM mosquitoes might have unforeseen ecological effects as well.
Summarize the points made in the lecture, being sure to explain how they respond to the specific concerns presented in the reading passage.
In the lecture, the professor casts doubt on the reading passage’s idea that releasing genetically modified (GM) Aedes aegypti mosquitoes to control dengue is dangerous. The professor asserts that scientific research and ecological considerations suggest that this method is both safe and beneficial.
Firstly, the passage claims that reducing Aedes aegypti populations could allow other, more dangerous mosquito species to increase and spread more potent forms of dengue. By contrast, the professor asserts that a scientific study analyzed this concern and found no such effect. The study observed that as Aedes aegypti mosquitoes were eliminated, the population of the Asian tiger mosquito, which carries a more dangerous dengue virus, remained stable. This indicates that the feared takeover by other mosquito species is unlikely.
Secondly, the author of the passage points out that GM mosquitoes are engineered to produce a defective protein, raising concerns that this protein could be transmitted to humans through mosquito bites. However, the lecture notes that only male mosquitoes will be genetically modified and released. Since male mosquitoes do not bite humans—only female mosquitoes do—there is no risk of the defective protein being passed to people, eliminating this concern.
Lastly, the reading states that introducing any genetically modified organism into an ecosystem could have unforeseen ecological consequences, citing a case where GM crops negatively impacted butterfly populations. On the contrary, the professor contends that such negative effects are rare, and most GM organisms introduced so far have not caused serious ecological harm. Additionally, he argues that using GM mosquitoes could have positive environmental effects by reducing reliance on toxic pesticides, which are currently used to control Aedes aegypti and are harmful to the environment.
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