Final answer:
The primary cause of extinction and endangerment of species is a combination of habitat loss, introduction of exotic species, and overharvesting, all of which are exacerbated by human activities and climate change.
Step-by-step explanation:
The primary cause of extinction and endangerment of species on Earth can be attributed to various factors, including habitat loss, introduction of exotic species, and overharvesting. Human activities such as agriculture, urbanization, deforestation, and the damming of rivers drive habitat destruction, while the increased mobility and trade contribute to the spread of non-native species which can outcompete the indigenous ones. Another significant threat is climate change, largely created by anthropogenic activities like the burning of fossil fuels, leading to drastic changes in ecosystems and raising sea levels. The synergistic impact of these factors, compounded by human overpopulation and resource exploitation, presents dire consequences for biodiversity and human welfare.