Life, Evolution, and the Scientific Method

Evolution

The process of change that has transformed life on Earth. Results in the adaptation of organisms to its environment.

What are the characteristics of a living organism? (5 things)

1. Made of membrane bound cells
2. Able to process information (hereditary and environmental)
3. Able to acquire and use energy
4. Capable of replication (reproduction)
5. Continually evolving

Does this image show a living organism or a non-living entity?

Living organism--note the body features.

Does this image show a living organism or a non-living entity?

Non-living entity--this is a virus!

What is a cell?

The smallest unit that can perform all of the required activities for life.

What is adaptation?

The process by which members of a population become better suited to some feature of their environment through change in a characteristic that affects their survival or reproduction.

What is biological fitness?

An organism’s ability to pass its genetic material to its offspring (reproductive success). Reflects how well an organism is adapted to its environment.

Natural Selection

Traits that are beneficial to the current environment and are “selected” within a natural population; those with the trait are able to survive and reproduce and those without it are not.

Artificial Selection

When humans select desirable traits within a domestic population (ex: GMOs).

In natural selection, do new traits appear before or after there is a selection from the environment?

Before; the environment does not create a new trait.

Speciation

A divergence process in which natural selection has caused populations of one species to diverge to form new species.

What is the difference between discovery science and hypothesis driven science?

Discovery science focuses on discovering nature whereas hypothesis driven science focuses on explaining nature.

Hypothesis

A proposed explanation for an observation. Four types: primary hypothesis, secondary hypothesis, alternative hypothesis, null hypothesis.

Prediction

What can be measured and what must be correct if a hypothesis is valid.

Theory

A well-established explanation for observations or a general class of phenomena that have been constructed using the scientific method and is supported by a wide body of evidence.

What is a test group?

The group(s) in the experiment in which the variable is being tested (receives the new treatment).

What is a control group?

The group in the experiment in which the variable is not being tested (does not receive the new treatment).

Independent Variable

A variable that stands alone and isn’t changed by the other variables being measured.

Dependent Variable

The thing that is being measured in an experiment. This happens as a result of an independent variable.

Control Variable

Any variable that’s held constant in a research study.

Qualitative Data

Descriptions of observations.

Quantitative Data

Recorded measurements that are sometimes organized onto tables or graphs.

Are viruses alive?

No, they are not made of cells; instead, they take over cells, which then multiply and hurt the person internally. They cannot be killed, just inactivated.