Chapter 23 - Notes PDF

Preview

Summary

Notes...

Description

1Chapter 23: Understanding Diversity: Systematics

1: Define and describe the terms systematics, taxonomy, taxon, and classification (remembering/understanding) 2: Define Linnaean terms and use the binomial system to arrange the Linnaean categories from most to least inclusive (remembering/understanding) 3: Describe the three domains and current kingdoms (remembering/understanding) 4: Describe, define and interpret a cladogram (remembering/understanding/applying) 5: Define, compare and contrast homology, homoplasy, analogous structures and analogous genes (remembering/understanding) [also covered in chapter 18] 6: Define, compare and contrast the concept of shared ancestral and shared derived characters as used when determining phylogenetic relationships (remembering/understanding/applying) 7: Define, compare and contrast outgroup, ingroup, monophyletic, paraphyletic, and polyphyletic taxa and apply them to a cladogram (remembering/understanding/applying)

Some Key Words Binomial nomenclature Genus a noun and the first part of the binomial designation Species an adjective and the second part of the binomial designation Characteristics Ancestral a characteristic that is present in an ancestor and all of its descendants Derived a characteristic that appears in a recent common ancestor and is not present earlier in that ancestral line Cladogram Clade a group of organisms that share a common ancestor Node a branching point on a cladogram [a change in characteristics occurs at a node] Root base point and common ancestor of a cladogram Groupings Ingroup all the organisms in the taxa being considered together Outgroup a taxon that branched off before the ingroup Mononphyletic includes a common ancestor and all of its descendants Paraphyletic includes a common ancestor but not all of its descendants Polyphyletic a group that has evolved from more than one ancestor and does not share a common ancestor Classification Convergent evolution evolution in similar environments results in similar characteristics [e.g. flight in birds and insects] Homologous gene genes that are related due to sharing a common ancestor Homologous structure similarities in structures due to sharing a common ancestor Homoplasy apparent similarity in traits due to convergent evolution or the reversal of a trait back to its ancestral state Parsimony selecting the simplest explanation for interpreting taxa Systematics constructing cladograms [phylogenetic trees] Phenetics [numerical taxonomy] uses the number of shared features to form taxa Evolutionay taxonomy uses the degree of evolutionary change and phylogenetic relationships to form taxa Phylgenetic systematics [cladistics] uses most recent common ancestor and shared and derived characteristics to form taxa Taxonomy naming, describing, classifying organisms Taxon a formal grouping of organisms [e.g. kingdom, phylum, family, etc.]

Chapter 23: Understanding Diversity: Systematics

Objective 1: Define and describe the terms systematics, taxonomy, taxon, and classification (remembering/understanding) Slide Classifying organisms Systematics___________________________________________________________________ Taxonomy ___________________________________________________________________ Taxon _______________________________________________________________________ Classification_________________________________________________________________

Objective 2: Define Linnaean terms and use the binomial system to arrange the Linnaean categories from most to least inclusive (remembering/understanding) No Slide Linnaean Nomenclature Binomial system each species assigned a unique two-part name First part Genus = a noun Second part species (specific epithet) = an adjective Both parts required for complete identification Example: Quercus [oak] alba [white] (white oak)

Objective 3: Describe the three domains and current kingdoms (rememgbering/understanding) [see book] No slide The three domains A. Archaea B. Bacteria C. Eukarya Kingdoms A. Bacteria B. Archaea C. Protista D. Plantae E. Fungi F. Animalia

No slide Taxonomic levels King Phillip Could Order Four Greek Salads K = kingdom P = phylum C = class O = order F = family G = genus S = species Each level is a taxon

Objective 4: Describe, define and interpret a cladogram and its use as a phylogenetic tree (knowledge/comprehension/analysis) Slide Moving away from strict Linnaean categories Classical phylogenetic trees ___________________________________________________________________________ Clade ___________________________________________________________________________ Becoming more reliant on molecular data __________________________________________________________________________ Currently a combination of classical and “modern” approaches

Slide

Cladograms is a type of phylogenetic tree _______________________________________________________________________ _______________________________________________________________________ Clade _________________________________________________________________________ Node ______________________________________________________________________ Root _______________________________________________________________________

Previous material Objective 5: Define, compare and contrast homology, homoplasy, analogous structures, and analogous genes (remembering/understanding) [already covered with chapter 18]

No slides Homologous structures Homology occurs when two species have a shared common ancestor Homologous structures Description _________________________________________________________________________ _________________________________________________________________________

Where _________________________________________________________________________ _________________________________________________________________________

Cengage Learning

Homologous genes _________________________________________________________________________

Homoplastic structures (homoplasy) Occurs when two different but related species share similar traits but have no common ancestor How ___________________________________________________________________________ Why _________________________________________________________________________ Result __________________________________________________________________________

Example of homoplastic structures Example using bats and birds _______________________________________________________________________________ _______________________________________________________________________________

Bats evolved from mammals Birds evolved from reptiles Cengage Learning

Analogous structures Occur when two different, unrelated species have similar traits but have no common ancestor How ____________________________________________________________________________ Result ____________________________________________________________________________

Campbell fig 26.7 pg 540

Cockroach wing

Vertebrate example of homologous structures and homoplasy Homology __________________________________________________________________________ Homoplasy __________________________________________________________________________

Two different species of salamanders

Back Objective 6: Define, compare and contrast the concept of shared ancestral and shared derived characters as used when determining phylogenetic relationships (remembering/understanding/applying)

Slide Shared characters Shared ancestral characters (plesiomorphies) _____________________________________________________________________ Example: vertebral column in subphylum Vertebrata Shared derived characters (synapomorphies) __________________________________________________________________________ __________________________________________________________________________ Slide Choosing taxonomic criteria Vertebrate ear bones Ancestral feature ____________________________________________________________________ Derived feature ____________________________________________________________________ Egg laying Ancestral feature ____________________________________________________________________ Derived feature ____________________________________________________________________

Objective 7: Define, compare and contrast outgroup, ingroup, monophyletic, paraphyletic, and polyphyletic taxa and apply them to a cladogram (remembering/understanding/applying)

Slide

Cladogram groupings Outgroup _____________________________________________________________________ Ingroup _____________________________________________________________________ Slide Monophyletic [one] grouping Common ancestor and all descendants________________________________________ Share at least on derived character ___________________________________________

Bio.Miami.edu

Slide Paraphyletic [subset] grouping Only some descendants of a common ancestor [subset] ___________________________ Will share ancestral characteristics ___________________________________________

Bio.Miami.edu

Slide Polyphyletic [multiple] grouping Do not share a common ancestor____________________________________________ Unnatural grouping such as protists__________________________________________

Bio.Miami.edu...