AP Biology Chapter 22 Terms (Descent with Modification – A Darwinian View of Life)

evolution
descent with modification, where modern species are descendants of ancestral species that were different from present-day species

pattern and process of evolution
pattern: revealed by data, observations of the natural world
process: mechanisms that produce the observed pattern of change

Aristotle
(384-322 BC) believed species were fixed and had certain affinities (likenesses) with each other

scala naturae (scale of nature)
Aristotle’s theory that organisms could be arranged on a scale of increasing complexity

Carolus Linnaeus
(1707-1778) interpreted the Old Testament that each species was created for a specific purpose and developed binomial nomenclature

binomial nomenclature
a format for naming species (genus, species) that contrasted Aristotle’s linear hierarchy by grouping similar species in increasingly general categories

fossils
the remains of organisms from the past, most found in sedimentary rocks

strata
superimposed layers of rock that are compressed when new layers of sediment cover the older ones that often contain fossils

paleontology
the study of fossils

Georges Cuvier
French paleontologist who opposed the idea of evolution and developed the idea of catastrophism

catastrophism
the principle that catastrophes eliminated species whole, and each boundary in strata represented a catastrophe

James Hutton
(b.1726) believed Earth’s geographic features could be explained by gradual mechanisms still operating today (i.e. valleys formed by rivers)

Charles Lyell
(b. 1797) used Hutton’s ideas to develop uniformitarianism

uniformitarianism
the idea that mechanisms of change are constant over time

Jean-Baptiste de Lamarck
proposed an incorrect mechanism for how life changes over time

Lamarck’s Theory of Evolution
he compared living species with fossil formations in several lines of descent using several incorrect principles: use and disuse, inheritance of acquired characteristics; proposed that organisms have an innate drive to become more complex

use and disuse
(Lamarck) the idea that parts of the body that are used extensively become larger and stronger, and those that aren’t used deteriorate

inheritance of acquired characteristics
(Lamarck) an organism can pass these characteristics down to their offspring (from use and disuse)

artificial selection
a process where humans have modified other species by selective breeding

Thomas Malthus
believed that much of human suffering (disease, famine, war) was a result of humanity’s potential to increase faster than food supplies and other resources – led to Darwin discovering a relationship between natural selection and the capacity of organisms to overreproduce

4 types of data that show evolution
1. direct observation of evolutionary change
2. homology
3. the fossil record
4. biogeography

homology
similarity resulting from common ancestry

homologous structures
structures that are similar in different species but have different functions

vestigial structures
remnants of features that served a function in the organism’s ancestors (snakes – pelvic and leg bones)

pseudogenes
inactive, vestigial genes that once were translated into useful structures in our ancestors but no longer serve a function

evolutionary tree
a diagram that reflects evolutionary relationships among groups of organisms that is a hypothesis of our evolutionary descent

convergent evolution
the independent evolution of similar features in differential lineages (similar adaptations in similar environments of different organisms)

analogous structures
features that share similar function but not common ancestry (the opposite of homologous structures)

biogeography
the geographic distribution of species influenced by many factors, including continental drift

continental drift
the slow movement of Earth’s continents over time

Pangaea
(250 MYA) the supercontinent composed of all Earth’s continents

endemic
organisms that are found nowhere else in the world (usually endemic species are found on islands)