Lecture 1_Introduction to Systematics Part 1 Flashcards
includes and encompasses
traditional taxonomy
Systematics
the description, identification, nomenclature,
and classification of organisms;
Taxonomy:
evolutionary history, of life.
phylogeny,
This definition of systematics is not novel, but
neither is it
universal
Systematics is founded in the principles of
evolution
its major premise being that there is
one phylogeny of life. The goal of systematists is,
in part, to discover that
phylogeny
in the broadest sense, means “change” and can be
viewed as the cumulative changes occurring since the origin of
the universe some 14 billion years ago.
Evolution
Biological evolution, the evolution of life, may be defined (as it
was by
Charles Darwin
“descent with modification.”
Evolution,
is the transfer of genetic material (enclosed within a cell, the unit of life) from parent(s) to offspring over time.
Descent
the time that life first originated some
3.8 billion years ago,
component of evolution
refers to a change in the genetic material that is
transferred from parent(s) to offspring, such
that the genetic material of the offspring is
different from that of the parent(s).
modification
which is a direct alteration of DNA
mutation,
existing genes are reshuffled in different combinations (during meiosis in eukaryotes, by the genetiC processes of crossing over and independent assortment).
genetic recombination
This modification may occur either by
mutation or by genetic recombination
is concerned with the identification
of the unique modifications of evolution.
Systematics
is descent with modification occurring by a change in the genetic makeup (DNA) of populations or species over time.
- evolution
- Evolutionary change may come about by two major or mechanisms:
(1) genetic drift
(2) natural selection,
GENETIC MODIFICATION IS RANDOM
GENETIC DRIFT
genetic change is directed and random
natural selection
is the differential contribution of genetic material from one generation to the next,
differential in the sense that genetic components of the population or species are contributed in different
amounts to the next generation;
Natural selection
Natural selection is the differential contribution of genetic material from one generation to the next,
differential in the sense that genetic components of the population or species are contributed in different
amounts to the next generation; those genetic combinations resulting in
increased survival or reproduction
A quantitative measure of this differential contribution
Fitness
a structure or feature that performs a particular function and
which itself brings about increased survival or reproduction. In a consideration of the evolution of any
feature in systematics, the possible adaptive significance of that feature should be explored.
adaptation
Natural selection results in an
adaptation
general units of evolution are
populations and species
is a group of individuals of the same species that is usually geographically delimited and that typically have a significant amount of gene exchange
population
are groups of populations that are related to one another by various criteria and that have evolutionarily diverged from other such groups.
Species
an ultimate result of evolution
speciation
the formation of new species from preexisting species
speciation
is itself a means of increaisng evolutionary diversity
lineage divergence
divergent lineages remain relatively distinct,
they may change independently of one another, into
what may be designated as
separate species
discipline of identifying and classifying organisms according to certain rules
taxonomy
are heirarchal levels based on hypothesized evolutionary relationships
taxonomy
evolutionary history of a group of organisms
phylogeny
To build phylogenetic trees, systematics gather all sorts of data:
- Fossil record
- Homology (vs analogy) & embryology
- Biogeography (distribution of species)
- Molecular data
