Chapter 2 | History of Evolutionary Thought

Great Chain of Being

Analyzing all living/nonliving & grouping them on a hierarchy

Linnaeus

• Devised a system of taxonomy

• Believed that life’s diversity reflected a divine plan

Taxonomy

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

Species name

Genus + specific epithet

Comparative anatomy

Studies the similarities and differences in the physical structures of different species

Supernatural world vs. Natural/Observable world

Relies on belief & faith vs. science & the scientific method

Buffon

• Earth formed according to the laws of physics and chemistry

• Living things are made from the same particles as non-living things

• Life emerged as distinct types; transformed when environment changed

Paleontology

Study of fossils & understanding where they came from; idea of extinction

Mary Anning

One of the first to discover dinosaurs & find evidence of extinction

Stratigraphy

Ordering fossils from oldest to newest, mapping time periods

Geology

The scientific study of Earth, its physical structure, composition, history, and the processes that shape it

Catastrophism

Discrete catastrophic events that changed the Earth

Uniformitarianism

Slow and gradual long-term change

James Hutton

Ocean that created rocks, being the Earth

Strata

Distinct rock layer that is visibly different from other rock layers based on types of fossils found in those geographic locations

Population ecology

Human population grows exponentially while food sources increase linearly

Lamarck

Acquired traits are inherited

Darwin

Published the Origin of Species —

• Iguanas & finches

• Found that the same species in similar environments acquire mutations that make them better suited to their environment

Wallace

Supported Darwin with his study of the Archipelago

Individuals vary in heritable traits

Characteristics better suited to the environment reproduce more — differential reproductive success

Populations are capable of exponential growth (Malthus) — some offspring will fail to survive and reproduce

Difference in reproductive success leads to the accumulation of favorable traits in future populations

Fitness

Measure of how many viable, fertile offspring are introduced to the next generation — survival is a pre-condition

Artificial selection

Humans choosing traits to evolve certain species faster than adaptations will normally occur

Mutation

Any heritable change in an organism's DNA sequence

Analogy

Similarity in traits due to convergent evolution

Vestigial structures

Structures that are no longer functional

Molecular homologies

Nucleotides & amino acids

Nicolaus Steno

• Was one of the first to recognize that fossils were the remains of once living organisms

• Recognized the basic principles of statigraphy

Georges Cuvier

Fossilized elephants differed from the skeletons of modern elephants in crucial ways