Presentation on theme: "Systematics Study of the diversity of organisms to classify them and determine their evolutionary relationships Taxonomy: naming, identifying and classifying."— Presentation transcript:
Systematics Study of the diversity of organisms to classify them and determine their evolutionary relationships Taxonomy: naming, identifying and classifying of species created by C Linnaeus
Taxonomy: Classification of Species Binomial system: all species have a 2 part name consisting of genus + specific epithet (usually latin) Domain*Eukarya *least specific, includes all others Kingdom Animalia PhylumChordata ClassMammalia OrderPrimates FamilyHominidae GenusHomo Species**H. Sapiens **most specific
Phylogenetic Trees Evolutionary tree showing common ancestors Divergence occurs due to derived traits traits not previously not seen
Phylogenetic Trees Species are most closely related to other species in same genus More distantly related to those of different families, orders
Cladistic Phylogenetic Trees A method of tracing evolutionary history of a group by using shared traits derived from a common ancestor to determine which species are most closely related Cladogram Outgroup not part of the group being studied Ingroup group being studied
Cladistic Phylogenetic Trees Which organism(s) have gizzards? Which organism (s) have an amniotic egg? Which organism has the most traits in common? The least?
Which of the Groupings Below is a True Cladogram? Explain why or why not each is or is not a true clade: a single common ancestor and all its descendents that share one or more shared derived traits.
Monophyletic grouping: a single ancestor gave rise to all species in that taxon and no other taxon Polyphyletic grouping: members of the taxon are derived from 2 or more ancestral forms not common to all members Paraphyletic grouping: a taxon excluding species that share a common ancestor that gave rise to the species included in the taxon
Tracing Phylogeny Fossil records and Behavior are used to determine relationships/common ancestors
Tracing Phylogeny: Morphological Data Homologous structures similar due to common descent – Developmental studies Convergent evolution distantly related species have same structure because developed in same environment Analogous structures same function without common ancestor
Tracing Phylogeny: Molecular Data Protein and DNA/RNA comparisons can be used to determine relationships/common ancestors Compare mitochondrial DNA (mtDNA) high mutation rate Molecular Clocks study neutral changes in DNA that accumulate at a constant rate; used with fossil common ancestor