Biology is the study of living things. There are seven characteristics shared by living systems:
- Cellular organization
- Ordered complexity
- Sensitivity (response to stimuli)
- Growth, development, and reproduction
- Energy utilization
- Homeostasis (maintaining constant internal conditions different from the environment)
- Evolutionary adaptation
The organization of the biological world is hierarchical. Each level builds on the level below it – the cellular level, the organismal level, the populational level, the ecosystem level, and the biosphere. Moving up the hierarchy, interactions occurring at lower levels can produce novel properties, called emergent properties, which are greater than the sum of their parts.
Five core concepts are emphasized in this textbook:
- Life is subject to chemical and physical laws.
- Structure determines function.
- Living systems transform energy and matter.
- Living systems depend on information transactions.
- Evolution explains the unity and diversity of life.
—July 2020
—March 2021
—April 2023
Lance Jones 