Answers:
1. Scientists are still not convinced why woolly mammoths disappeared. Some consider the reason is associated with environmental changes at the end of the Ice Age, including a lack of fresh water. Others, however, criticise humans who hunted the shaggy beasts to extinction.
2. All organisms have adaptations that allow them to persist under specific conditions in their surroundings or ecosystems. Some of the abiotic, or nonliving, factors that affect organisms' capacity to survive include temperature, light availability, soil type, water, salinity levels of soil or water, oxygen, acidity/alkalinity (pH levels) of soil or water, inorganic nutrient levels, other chemicals, radiation, ocean waves, topographical features and altitude.
3. Since its beginning, life on earth has had to adapt to changing environmental conditions - this describes a driving force of development. Theorists studies how organisms recognise and react to changes in their environment, and examines the different behavioural, physiological and molecular mechanisms underpinning environmental (stress) adaptation.