All living things share basic characteristics.
Traits associated with life. (Figure 1.2) Living things are made of/contain atoms/molecules Lipids Carbohydrates Proteins Nucleic Acids Living things are composed of cells Living things reproduce Metabolism Chemical reactions are the basis for metabolism. Living things respond to the environment Homeostasis – maintain relatively constant internal environment. Evolve Adaptation. Natural selection.
Living things share an evolutionary history. Classification/grouping – family tree, for example, canids http://www.nhm.org/exhibitions/dogs/evolution/evolution.html Shared characteristics indicate a common ancestor. More characteristics in common indicate a closer common ancestor. Kingdoms, e.g., Animal Kingdom. (Figure 1.4) Six Kingdoms (Figure 1.3)
The smallest grouping is the species.
Life has many levels of organization. (Figure 1.6) Cells are the smallest unit of life. Hierarchy/organization Molecule, cell, tissue, organ, organ system, individual, population, community, ecosystem, biosphere.
At each level, the whole is greater than the sum of the parts – Emergent properties. e.g., H2O, table salt (NaCl)
Describe a system/instance/example where emergent properties are evident.
Science and Society
How do we know?
From Latin scientia, knowledge,
Using scientific processes in order to discover empirically proven truth.
Organized body of knowledge.
Usually involving measuring something, prevention, or causation. (Cause and Effect) http://en.wiktionary.org/wiki/Science Causally accounting for physical phenomena explanations are testable.
Science is not a source of subjective value judgments.
Science is a process of inquiry and asking the right questions.
Science is a way of knowing, gaining knowledge about the natural world.
Hypotheses and theories.
The terms "hypothesis", "theory", and "law" have a different use in science.
An hypothesis is a suggested explanation of a phenomenon. It will enable predictions of an experiment or of further observations.
Theories are backed by many observations and much experimental data. They come from hypotheses that have withstood repeated testing and observation. http://en.wiktionary.org
Atomic theory, Cell theory
Some knowledge (based on theory) is practically absolute. e.g., as demonstrated by a pencil placed in water. (image) (wave theory of light)
Laws are typically conclusions based on the confirmation of hypotheses through repeated scientific experiments over many years, and which have become accepted universally within the scientific community. (Boyle’s law, Charle’s law) (Newton’s laws, e.g., gravity) http://en.wiktionary.org
Goals and results of science
Science is tentative – always open to new explanations.
Science results in testable explanations about the physical world.
These explanations are always open to modification as new facts are discovered.
“Modern science is a process by which we try to understand how the natural world works and how it came to be that way.”
Certain rules must be followed, but there is NO one "scientific method.” The rules of science are intended to make the process as objective as possible.
One constant theme is that there is no certainty in science, only degrees of probability (likelihood), and potential for change.
Scientific understanding can always be challenged, and even changed, with new ways of observing, and with different interpretations. The same is true of scientific facts. New tools and techniques have resulted in new observations, sometimes forcing revision of what had been…