The theory of evolution is supported with the following evidence1. Fossil record- using relative dating and carbon-14 dating to

determine age of extinct and extant groups of organisms.2. Biogeography- comparing differences in groups of organisms

in line with the migration of continents and other changes in geography

3. Comparative Anatomy- looking at common anatomical structures (homologous or vestigial features)

4. Comparative Embryology- looking at common tissue development

5. Molecular Biology- comparing the DNA and protein sequencing of extant organisms and determining the accumulation of mutations since they shared a common ancestor (phylogeny- an evolutionary tree)

Review: Evidence for Evolution

Systematics: discipline that focuses on classifying

organisms and their evolutionary relationships. Its tools include fossils, morphology, genes,

and molecular evidence.

Systematics is currently modifying the work of Linnaeus’s classification system

Taxonomy is an ordered division of organisms into categories based on a set of characteristics used to assess similarities and differences.

What is a cladogram?A graphic representation of an organism’s

phylogeny, or evolutionary history

An evolutionary history

A clade is a group of related organisms. A cladogram is made with groups of clades, see images below.Notice that they tell a story of common ancestory and speciation.

Understanding phylogenygreen- monophyletic (ancestor and all of its descendents)blue- paraphyletic (some of the descendents of an ancestor)pink and orange – polyphyletic (have different ancestors)

Simple to Complex

Primitive characteristics are at the base of a cladogram and may include outgroups (unrelated members of a phylogeny ie. Algae and Plants)

Shared derived charactersitics are shared with every organism that branches after that point

Derived characteristics are more specific and only pertain to those on that specific branch

ex.Chloroplast is a primitive characteristic of plants, vascular tissue is a shared derived, while the flower is derived only for the angiosperms

Primative, Shared derived and derived chatacteristics??? handout