Transcript Evolution: Animal Diversity - Part 1 - Cal State LA

Evolution: Animal Diversity Part 1
Biology 155
Krilowicz
Spring 2010
I. Definitions
A. Taxonomy: the science of classification of
living things; older schemes were constructed
without regard for evolutionary relationships
among organisms
B. Phylogeny: the science that examines the
evolutionary relationships among organisms;
most taxonomic schemes in use today are based
on phylogeny
II. What types of information can be
used to construct phylogenetic
schemes?
A. Anatomy: similarities or differences in structure
of modern day forms
1. Adult structures –
The bones of a human arm are very similar to those in a
bird wing, so probably closely related animals
(homologous structures)
The vertebrate limbs are very different from arthropod
limbs, so these two groups are more distantly related
Various vertebrate forelimbs
Various arthropods
Fig. 13.5A
II. What types of information can be
used to construct phylogenetic
schemes? - continued
A. Anatomy: similarities or differences in
structure of modern day forms – continued
2. Embryonic structure –
All vertebrate embryos go through very similar
developmental patterns, so probably closely
related animals
The development of vertebrates (deuterostomes)
differs from arthropods (protostomes), so
these two groups are more distantly related
Fig. 13.5B
Two vertebrate embryos
at similar stages in
development
II. What types of information can be
used to construct phylogenetic
schemes? - continued
B. Physiology: function of present day organisms
Mammal and reptile lungs function in essentially the
same manner, so probably closely related animals
Insects use a tracheal system to exchange gases that
functions very differently from vertebrate lungs,
so these two groups are more distantly related
II. What types of information can be
used to construct phylogenetic
schemes? - continued
C. Geologic (Fossil) Record: can be used to
determine –
1. Anatomy of extinct organisms
2. First appearance of currently living
organisms
II. What types of information can be
used to construct phylogenetic
schemes? - continued
D. Biochemical Information: how similar is
the structure of enzymes, ribosomes, etc.
among groups of organisms?; Reflects
similarity in DNA because information in
the genes is used to construct proteins, RNA
and other biological molecules
II. What types of information can be
used to construct phylogenetic
schemes? - continued
E. Gene (DNA) Sequence Data – how
similar is the genetic material among living
organisms? ultimately what scientists really
want is an answer to this question to
definitely construct phylogenetic trees
Has recently led to a reorganization of living
things into three domains versus five
kingdoms
Five kingdom system of
classification
Three domain system
of classification
III.The Taxonomic Hierarchy:
Domain (three of these)
Kingdom
Phylum (Animals) or Division (Plants)
Class
Order
Family
Increased
relatedness =
Genus
more traits in
Species
common
Only group
with a
biological
definition
Definition of a species
• A group of actually or potentially
interbreeding organisms that are
reproductively isolated* from other
organisms
* Either cannot mate with another organism or
mating produces sterile offspring
Species names have two parts
Genus species
Capitalized
italicized
lower case
italicized
Usually Latin
Example – Felis domesticus