Sept 4 lec 2 required reading 3 introduction to biology and tree of life. 2. 3 origins of life: history of life on earth. 1. 1 properties of life i. ii. iii. iv. v. vi. vii. Life is not a random subset of its environment; made up in a specific way for natural processes. Conditions must be met for something to be considered living. Display order [nucleic acids internal separate from external] The cell is the basic unit of life (cell theory) and cells have the internal environment that are separate and distinct from their surroundings which allow processes essential to life and the creation of specialized internal environment. Maintaining processes and internal environments independent of the environment requires energy. Entities that reproduce are favoured by natural selection because they are descendants of individuals that suit the environment. Survival requires adaptive responses and the organisms that respond are favoured by natural selection. Optimization of biochemistry to maintain a relatively constant environment.