BIODIVERSITY, CHANGE AND BIODIVERSITY, CHANGE AND CONTINUITYCONTINUITY

Evolution

Introduction

– Why evolution

– Nature of Science

WHY EVOLUTION?

• Evolution as a PROCESS is a SETTLED THEORY accepted by biologists all over the world.

• Evolution provides a framework for understanding all aspects of biology (classification e.g. simple to complex organisms, adaptation e.g. function, environment & structure)

WHY EVOLUTION? Cont.WHY EVOLUTION? Cont.Evolution is integral to medicine andagriculture studies / research such as

- Biotechnology, GMO e.g., generate insulin by bacteria,

- Tracing evolutionary origins of diseases,

- Selective breeding of plants and animals,

- Resistance of insect pests to insecticides

WHY EVOLUTION? Cont.WHY EVOLUTION? Cont.

Evolutionary biology provides tools for many studies in genetics/genomics

- Relationships between groups,

- Research,

- Resolving legal issues such as

DNA fingerprinting & Sources of AIDS infections,

Nature of ScienceNature of Science• Science seeks to explain the natural world

and its explanations are tested using evidence from the natural world.

• Scientific ideas are developed

through reasoning.

• What we know from scientific study is based on inferences from data.

Nature of ScienceNature of ScienceCharacteristics of science

• Conclusions of science are reliable, though tentative. Might change over time

• Science is non-dogmatic.

• Science cannot make moral or aesthetic decisions.

• Science is not democratic. Science is based on evidence, not votes.

Nature of ScienceNature of Science• Facts:

Accepted to be true and universal

• Hypothesis:

An educated guess which is testable based upon observation(s)

• Theory:

A scientific theory is accepted to be “true” by the scientific community as a whole.

Nature of ScienceNature of ScienceScientific Theory

The Development of a Simple The Development of a Simple TheoryTheory

• Observation: Every swan I've ever seen is white. • Hypothesis: All swans must be white. • Test: A random sampling of swans from each continent

where swans are indigenous produces only white swans. • Publication: "My global research has indicated that

swans are always white, wherever they are observed." • Verification: Every swan any other scientist has ever

observed in any country has always been white. • Theory: All swans are white. • Prediction: The next swan I see will be white.

The Development of a Simple The Development of a Simple Theory (Cont.)Theory (Cont.)

• Note, however, that although the prediction is useful, the theory does not absolutely “prove” that the next swan I see will be white.

• Thus it is said to be falsifiable. If anyone ever saw a black swan, the theory would have to be tweaked or thrown out.

Evolution is NOT the process of Evolution is NOT the process of superior animals triumphing over superior animals triumphing over

inferior ones, but is rather a inferior ones, but is rather a series of alternative strategies series of alternative strategies that have arisen in response to that have arisen in response to

changing environments. changing environments.

• No organism is better or worse than another.

• Arthropods (crabs, spiders, insects etc.) are more successful than vertebrates when one considers the number of species, number of individuals, and number of adaptations to different environments and habitats.

• In a similar way, humans are more successful than other modern apes in having a large number of individuals adapted to living in different environments.