Principios de Taxonomia

230j Scientific Terms
Autapomorphy An alteration of traits that distinguishes the organisms of two sister
species from each other as well as from the organisms of the stem species after a
cladistic bifurcation.
Barcoding A method of species identification, based on particular DNA sequences
(so-called barcodes). Although barcoding is a method of diagnosis, it is often used
misleadingly as a species concept, defining every organism as a different species that
differs with respect to phylogenetic distance.
Biological species A term for a species concept that was used by Ernst Mayr as a
synonym for the species as a reproductive community to make it clear that the
reproductive community is not a mental construct, but an object that actually exists in
nature.
Biparental reproduction The production of offspring from a zygote that arises via
fusion of egg and sperm from different parental individuals (see uniparental
reproduction).
Birds, migratory and sedentary Many bird species are polymorphic. Their
populations consist of two different morphs, comparable to the existence of
males and females within a given species. Some individuals occupy the breeding
grounds only during reproduction, whereas others remain in their breeding habitats
permanently. This dimorphism is genetically based.
Butterflies, uni-, bi- and multivoltine On the northern hemisphere, many
butterflies include different morphs that are adapted to different geographical
latitudes. In the South, bi- and multivoltine morphs dominate. Here, the
butterflies produce two or more generations each year and therefore occur in
quite large numbers in this region. In the North, however, butterflies of a given
species hatch only once in a year. They generate only one generation and are
accordingly rarer. In an overlapping region, both morphs occur side by side. This
polymorphism is genetically based.
Clade Portion of the cladistic phylogenetic tree that contains at least one bifurcation
(see lineage) (Figure 2.6).
Cladistics Science addressing the phylogenetic branching patterns of taxa,
organisms or DNA sequences.
Cladogenesis Branching of a phylogenetic stem species into two daughter species
in the course of evolution. Cladogenesis is the fragmentation of a group of cohesively
connected organisms into two separate groups (Figure 2.3). Therefore, cladogenesis
is speciation (see anagenesis).
Class A group of objects with equivalent traits, in contrast to a group of objects that
are relationally connected which each other (Figure 2.5). A class is always a universal.
It is a group of objects whose existence is not limited temporally or spatially but that
can occur at any time anywhere in the world. A class is the opposite of an individual.
An individual exists only once in the world. In taxonomy, the attempt to combine all