Evolution, the Themes of Biology, and Scientific Inquiry

Biology as a Quest: Biology is the scientific study of life, described as an ongoing inquiry about the nature of the living world. It addresses ambitious questions such as how a single cell becomes a complex organism (like a tree or a dog) and how biological forms interact within ecosystems.

Defining Life: Life is recognized through the properties and processes that living things exhibit:

• Order: Characterized by highly ordered structures, such as the arrangement of seeds in a sunflower.

• Evolutionary Adaptation: Adaptations evolve over generations through the reproductive success of individuals with heritable traits best suited to their environments (e.g., the camouflage of a pygmy sea horse).

• Regulation: Mechanisms like blood flow through a jackrabbit’s ears help maintain constant body temperature (homeostasis) by adjusting heat exchange with the air.

• Energy Processing: Organisms use chemical energy stored in food (e.g., nectar for a butterfly) to power work like flight.

• Growth and Development: Inherited information in genes controls the growth pattern of organisms, such as an oak seedling.

• Response to the Environment: Organisms respond to stimuli, such as a Venus flytrap closing rapidly when a grasshopper lands on it.

• Reproduction: Living things reproduce their own kind.