BIOSCI 109: Lecture 13 - Evolution and the Nature of Science

What Does Evolutionary Biology Ask?

Questions about origin, the what, why how, when, and where about the oriigns of genes, species, groups, ecologies, and so on

Questions about change, how the hereditary and genetic change occurs, the mechanisms that caused it, and so on

Evolution

“Descent with modification” which answers both questions above.

Descent being the species descending from ancestral species through the normal process of reproductions. This explains why there are similarities between species. Modification being how the observed genetic changes occur not just in individuals but in whole species (natural selection and other processes).

What Isn’t Evolution

There are many “contemporary” views of evolution that don’t describe how scientists view evoltuion. It is not linear, like some sort of ladder. It is not progressional, as if things are becoming better. It is not moving towards a higher plane.

Phylogenetic Trees

Visuals that show us descent with modifications. It shows how organisms descended from species to species, and sometimes the changes and modifications it has gained over time.

Why Study Evolution?

Evolutionary biology serves as the central organising theory of biology. Understanding aspects of biolog also requires an understanding of evolution to truly understand its origins.

Evolution Controversies

Evolution’s answers about origins and nature of humans can challenge our religious, traditional, and even progressive beliefs. There are many reasons why people may be opposed to it, there has been controversies ever since its conception.

Nature of Science

It is a way of thinking and seeking tests, experiments, and data to support hypotheses that better represent and approximate the world. There are many principles it follows:

• Testing (needing empircal data)

• Evidence (that evidence beats everything else)

• Tentativeness (the humility and openness to be wrong)

• Recording & Publishing (carefully recording observations and sharing results)

• Methodological Naturalism (science that explains the world via natural laws)

• Applying Math (having data whenver possible)

• Open to All (scientific knowledge shouldn’t be owned)

• Open for Participation (as long as evidence is present)

• Academic Freedom (able to be criqued)

Theories

Theories integrate facts (observations), hypotheses, and laws (broad generalisations that is university true). Theories are often miscontrused to be “false” because they’re not" “facts”. Something being described as a theory doesn’t indicate doubt, but instead room for improvements and changes.

Microevolution

Evolution within populations, the changing gene frequencies accross generations (population genetics). Typically occurs due to natural selection, genetic drift, and so on.

Macroevolution

Evolution across multiple species, it is the speciation and extinction events over time, the evolution of major adaptations, and studied with phylogenetics.