The concept of 'de-extinction'—bringing extinct species back to life through genetic engineering—has gained traction among scientists. While some argue it is a noble endeavor, I contend that de-extinction is impractical, ecologically risky, and ethically questionable. First, the technical challenges are insurmountable. DNA degrades over time, and for species extinct for centuries, like the woolly mammoth, viable DNA is scarce. Even with CRISPR technology, reconstructing a full genome requires millions of base pairs, and errors are inevitable. Second, reintroducing extinct species could disrupt modern ecosystems. These species evolved in ancient environments, which no longer exist. For example, if we resurrect the passenger pigeon, it might compete with existing birds for food and habitat, causing unforeseen ecological imbalances. Third, de-extinction diverts crucial funding and attention from conserving currently endangered species. With limited resources, investing millions in resurrecting a few individuals does little for biodiversity, whereas protecting living species yields immediate benefits. Thus, de-extinction is a misguided priority that fails to address pressing conservation needs.
🎧 听力讲座
🎯 模拟考试环境：先点「播放讲座」听完内容，再作答。听力原文默认隐藏。
The reading presents a pessimistic view of de-extinction, but its arguments are flawed. First, technological hurdles are not as daunting as claimed. Recent advances in paleogenomics have allowed scientists to sequence DNA from ancient remains, and new gene-editing tools like base editing reduce errors significantly. The woolly mammoth project, for instance, has already mapped most of its genome using well-preserved specimens from permafrost. Second, the ecological concerns are overstated. Modern ecosystems are not static; they have been altered by human activity, and reintroducing keystone species like the mammoth could restore lost functions. For example, mammoths could help maintain grasslands in the Arctic, which would slow permafrost thaw and mitigate climate change. Third, the claim about resource diversion is a false dichotomy. De-extinction research often develops technologies that benefit living species, such as genetic rescue for endangered animals. Moreover, public enthusiasm for de-extinction can raise awareness and funding for conservation overall, not detract from it. Therefore, the objections raised in the reading are short-sighted.
📝 写作提示 Summarize the points made in the lecture, being sure to explain how they cast doubt on the specific points made in the reading passage.
