Prologue

The New BiologyBiological View of AIDS

Virus HIV causes cells to become factories.

Over 25 million dead, over 40 million infected.

Scientists working on a vaccine.

Growth HormoneOriginal GH came from

pituitary glands of deceased.

Currently produced by bacteria

A problem of distribution

Solving ProblemsScientific problems are

solved by using observations – not feelings.

Data is information gained through observation.

The scientific method helps us to determine what is reasonable and what is not.

Solving ProblemsTesting a

Hypothesis: A controlled experiment is designed.

The experimental group has one variable changed.Independent vs.

Dependent

The control group stays the same.

Evolution: Science at WorkA theory explains current

observations and predicts new observations.

19th century biologists noticed that fossils were different from living organisms.

Theory of Evolution: species have changed over time in response to changes in their environment.

Evolution: Science at Work Jean Baptiste Lamarck

suggested that life can change.

He suggested evolution was a process of adaptation.

The more a body part was used the stronger it got and vise versa.

Evolution: Science at WorkA hypothesis is an

explanation that is testable through experimentation or observation.

If . . . Then . . .because . . .

Lamarck’s predictions that acquired characteristics are inherited can not be proven true.

Evolution: Science at WorkBritish naturalist Charles

Darwin developed a theory of evolution that is still in use.

Darwin used James Hutton’s hypothesis of uniformitarianism as the basis for his theory.

If Earth has such a long history of change – shouldn’t the organisms on it have changed as well?

The Theory of Natural Selection In 1859 Darwin published

the book “The Origin of Species”.

He stressed natural selection – organisms best suited for their environment survive – as a means for evolution.

Some members of a species have characteristics that enable them to survive.

The Theory of Natural SelectionA species is a group of

organisms who can produce viable offspring.

Successful organisms pass on their successful characteristics to their offspring.

These successful characteristics are referred to as adaptations.

The Theory of Natural SelectionThomas Malthus: if

organisms reproduce at a steady rate – they would outstrip the food supply.

Not all organisms live long enough to reproduce because resources are limited.

Competition for limited resources drives evolution.

The Theory of Natural SelectionSmall differences

called variations can either help or hinder members of a population.

Natural selection eliminates organisms with variations that are not advantageous.

The Theory of Natural SelectionGood theories lead to

logical hypotheses.

Darwin’s theory of descent with modification – related organisms share a common ancestor – can be tested.

Lamarck and Darwin proposed different theories to explain the same observation.

Science as a Way of Knowing Characteristics that define

science:

The natural world can be investigated.

Science is based on observations and controlled experiments.

The results of the experiments must be repeatable.

The findings of science must be refutable – if a hypothesis is not supported by evidence it must be rejected.

Science as a Way of KnowingCopernicus and Galileo

concluded that Earth revolved around the sun.

These ideas contradicted scriptures – Galileo was arrested.

Rejecting science does not change the science – it merely prevents people from learning and understanding …

Science as a Way of KnowingPseudoscience is

false science – the research does not meet the definition of science.

Creationism is pseudoscience in that the logic behind it cannot be tested with the scientific method.

Science as a Way of Knowing5 Questions on

research:

What is the question?

What are the data and how were they obtained? – separate data from opinions.

What do the data mean? – does the data support the argument.

Science as a Way of Knowing5 Questions on

research:

Who is reporting the data? – determine credentials and background.

Is our knowledge sufficient to answer the question.