1. Phylogeny & Systematics Chapter 25

2. Phylogeny: the evolutionary history of a species

3.  Systematics: the study of biological diversity in an evolutionary context  Analytical approach  Focuses on morphological, biochemical and molecular resemblances Constructing a Phylogeny:

4.  The fossil record: the ordered array of fossil, within layers (strata) of sedimentary rock Constructing a Phylogeny:

5.  Sedimentary rock(?) :  Richest source of fossils  Lake Turkana Boy(1984) The fossil record

6.  Limitations? The fossil record

7.  Morphological and Molecular Homologies:  Homologies= similarities do to shared ancestry Constructing a Phylogeny:

8.  Homology vs. analogy  Convergent(independent) evolution vs shared ancestry  Similar environmental pressures can produce analogous adaptations in organisms from different lineages Some more challenges:

9.  The tracing of evolutionary relationships (phylogenetic tree)  Linnaeus(taxonomy)  Binomial Nomenclature Phylogenetics

10.  Binomial Nomenclature-two part naming system  First part: genus(genera)  Second part: species(specific epithet) Phylogenetics

11. Hierarchical Classification:

12.  1. Domain  2. Kingdom  3. Phylum  4. Class  5. Order  6. Family  7. Genus  8. Specie s Hierarchical Classification

13.  1. Eukarya  2. Animalia  3. Chordata  4. Mammalia  5. Primate  6. Homidae  7. Homo  8. sapiens Example:

14.  Classification is reflected in the branching of the phylogenic trees  Evolutionary relationships are traced between some of the taxa What is the connection between classification and phylogeny:

15.   Cladograms: diagrams that show patterns of shared characteristics   Clade: a group of species that includes an anestral species and all its descendants. Phylogenetic systematics:

18.   Cladistics: the analysis of how species may be grouped into clades Phylogenetic Trees

19.  Monophyletic- single ancestor that gives rise to all species in that taxon and to no species in any other taxon  The only valid clade(cladogram) Valid vs. non valid clades

20.  Paraphyletic- lacks information about some species  Consists of an ancestral species but not all descendants  Not valid Valid vs. non valid clades

21.  Polyphyletic-grouping of several species that lack a common ancestor  Not valid Valid vs. non valid clades

23. { A Cladogram

24. http://ccl.northwestern.edu/simevolution/obonu/cladograms/Open- This-File.swf  http://ccl.northwestern.edu/ simevolution/obonu/cladog rams/Open-This-File.swf http://ccl.northwestern.edu/ simevolution/obonu/cladog rams/Open-This-File.swf http://ccl.northwestern.edu/ simevolution/obonu/cladog rams/Open-This-File.swf