[Campbell Biology P.590] The text discusses the possibility of a "sixth mass extinction" dri... | Practice Question

The text discusses the possibility of a "sixth mass extinction" driven by human actions. Which of the following statements accurately describe factors contributing to the current alarming rate of species decline or distinguish this potential extinction event from past 'big five' events as described in the text?

  • A: Habitat destruction, introduced species, overharvesting, and climate change are all identified as significant drivers of current species decline.
  • B: Unlike past mass extinctions primarily caused by natural geological or extraterrestrial events, the potential sixth mass extinction is primarily driven by anthropogenic factors.
  • C: The current extinction rate (100-1,000 times background rate) confirms that the total number of species losses has already surpassed those of the 'big five' mass extinctions.
  • D: The difficulty in assessing the full extent of the current crisis is solely due to the lack of sufficient monitoring programs globally.
  • E: Climate change is a new factor in mass extinctions, having no historical precedent according to the fossil record.

Explanation

The text states, "Monitoring programs show that many species are declining at an alarming rate due to habitat loss, introduced species, overharvesting, and other factors. Recent studies... suggest that climate change may hasten some of these declines." This supports option A. The text describes past mass extinctions Cretaceous caused by asteroid impact and volcanism, while the current one is linked to "human actions," supporting option B. Options C, D, and E are contradicted by specific statements in the text.