321 Flashcards
Monophyletic
A taxon in which all species share a common ancestor, & all species derived from that common ancestor
Polyphyletic
Derivation of a taxon from two or more ancestral sources
Paraphyletic
A taxon in which all species share a common ancestor, but not all species derived from that common ancestor are included
Taxonomy vs systematics
» Taxonomy: The science of naming, describing and classifying organisms and includes all plants, animals and microorganisms of the world.
» Systematics: The science that studies the distinctive characteristics of species and how they are related to other species through time. Field of biology that studies and tries to establish phylogenies (= evolutionary histories)
Plesiomorphy
Near ancestral type
Symplesiomorphy
Shared ancestral type
Apomorphy
Away from ancestral
Process (microevolution)
to do with how the process occurs
History (macroevolution)
process created history with many unique events
hutton
- Uniformitarianism
– Present is the key to the past - Gradualism
– Features of the earth result from slow accumulation of events
such as those we see occurring now
Thomas Malthus
populations grow
exponentially while agriculture grows
linearly; therefore, populations will always
outstrip their resource base.
Lamarck
Theory of Evolution (1809)
* Organisms continually change to become better
adapted to their environment
* A feature acquired during an individual’s lifetime could be passed on to offspring
Cuvier
Strongly opposed the idea of evolution
* Catastrophism
* Only natural catastrophes, such as the “Great
Flood”, could account for the form and nature of
a 6,000-year-old Earth
Lyell
The earth is very old
* Made Hutton’s ideas accessible to a wide
audience, including Darwin
* Advocated uniformitarianism and
gradualism
darwin observations
Similarity (unity) & dissimilarity (diversity)
* Redundant forms from place to place
* common ancestry
* Variation on a basic form within a region
* Due to descent with modification
wallace
‘Father of biogeography’
* Independently proposed theory of
evolution due to natural selection
clade
A clade is a grouping that
includes a common ancestor
and all the descendants (living
and extinct) of that ancestor.
homology
Similarities due to shared ancestry
» Do not necessarily have the same function
» Sharing of homologies among species indicates that
they have evolved from a common ancestor that
possessed the same feature