BIODIVERSITY, CHANGE AND CONTINUITY 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. Evolution is integral to medicine and agriculture 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. 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 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 Science Characteristics 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 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 Science Scientific Theory

The Development of a Simple Theory 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 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 superior animals triumphing over inferior ones, but is rather a series of alternative strategies that have arisen in response to 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.