Chapter 2: Biology from Natural Philosophy to Dawn
2.1) Taxon (plural, taxa):Agroup of organisms that a taxonomist judges to be a taxonomic unit,
such as a species or order.
Taxonomy: The science of describing, naming & classifying species of living or fossil
2.2) Paleontology: The study of prehistoric life.
Extinction: The permanent loss of a population/species arising with the death or failure to
breed of the last individual.
2.3) Uniformitarianism: The idea that the natural laws observable around us now are also
responsible for events in the past. One part of this view, for example, was
the idea that the Earth had been shaped by the cumulative action of gradual
processes like sediment deposition & erosion.
Homologous: Traits are similar because they are inherited from a common ancestor.
Analogous: Traits are similar because they have converged on a shared form. They aren't
derived from a common ancestor.
Adaptions: Inherited aspects of an individual that allows it to out compete other members of a
population that lack the trait or have a different version.Adaptations are traits that
have evolved through the mechanism of natural selection.
2.4) Sexual Selection: arises when individuals of one sex (usually males) compete with each other
over access to individuals of the other sex. It can lead to the evolution of
traits like showy ornaments or weapons that improve the individuals chances
Statigraphy: Study of layering rock (stratifaction) as a method for reconstructing the past.
– In the 1600's, naturalists came up with rules for naming species & classifying them.
– In the mid-1700's Swedish botanist Carl Linnaeus (father of modern taxonomy) invented a
system to classify species into groups (taxa) according to traits.
– (Kingdom, Phylum) Class, Order, Family, Genus, Species
– He believed that patterns of life hadn't changed since the beginning of the world
– Nicolaus Steno (father of geology & statigraphy), 1700 Dutch anatomist/bishop of catholic
church), discovered fossils
– Studied fossilized shark teeth (tongue stones), proposed they had turned to stone after some
– Seashells found on mountaintops because the seas was initially over the mountains (layers of
rock on mountain = sedimentation)
– Georges-Louis Leclerc, Comte de Buffon
– researched wood strength and wrote encyclopedia
– one of the earliest naturalists to argue that life had changed over time
– when life first emerged, it was divided into distinct types that could be transformed as
– “Populations change over time” – French paleontologist Georges Cuvier discovered fossils of mammoths & mastodons; relative
to the elephant, but extinct.
– Extinct species became documented & reasons for extinction were investigated
– James Hutton, Scottish farmer, realized rocks formed through slow changes (erosion,volcanoes,
– small changes = vast changes as time progressed
– Therefore, the Earth must be vastly old (accepted in 1800's)
– William Smith (british canal surveyor) discovered that layers of rock contain distinctive groups
of fossils (s