Many living things become extinct for reasons that are not obvious. For example, the dodo did NOT become extinct because people killed it. Rather, it died off because people introduced dogs and pigs. The dodo was flightless and so laid its eggs in a nest on the ground. The dogs and pigs ate the eggs, so the dodo very quickly became extinct.
This tells us that we may do things that have a 'knock-on' effect which then causes extinction.
