Quick Write What is evolution? Describe the mechanism and how, depending on the environment, the selection can vary. Give examples of how genetic variation can enter a population at the molecular level AND at the population level.

Evolutionary History and Biodiversity Ms. Klinkhachorn March 25, 2011 AP Biology

Saturday Sessions THIS Saturday (April 2) 9 to 11 am at Uplift April 9 New information NOT review April 9 10 to 1 pm April 30 9 am to 1 pm May 7 (?)

Midterm Vocab questions, short answer, multiple choice Covers evolution

Chapter 26: Phylogeny and the Tree of Life

Introduction There are an estimated 100 million+ species in the world Only 1.5 million are named! How do scientists categorize and name these species so that the scientific community understands what is being discussed? How do we avoid confusion?

Phylogeny Phylogeny is the evolutionary history of a species or a group of related species Uses Fossils Morphology Homologous structures Genetic information

Taxonomy Taxonomy is the science of naming and classifying living things Names written in Latin, internationally recognized system Organisms are put into categories based on a number of characteristics Organisms that are similar to each other are placed in the same categories

Classification Organisms are classified by: physical structure (how they look) embryonic similarities (embryos) genetic similarities (DNA) biochemical similarities (enzymes)

Classification Levels Levels within levels Each level is generally referred to as a taxon From least specific to most specific: Kingdom Phylum Class Order Family Genus Species

How Can We Remember This? King Philip Came Over For Ginger Snaps Kingdom Phylum Class Order Family Genus Species

Binomial Nomenclature Two-part naming system consisting of the genus and the species Underlined or written in italics Capitalize the genus Developed by Linnaeus Example: Canis familiaris

Animalia Chordata Reptilia Saurischia Tyrannasauridae Tyrannosaurus rex

Common Name: Tomato Plantae Streptophyta Asteridae Solanales Solanaceae Lycopersicon esculentum

Example: Mushroom What is the most specific classification? Fungi Zygomycota Zygomycetes Mortierellales Mortierellaceae Lobosporangium transversale What is the most specific classification? What is the Phylum? What is the Genus?

Example: Leopards Animalia Chordata Mammalia Carnivora Felidae Panthera pardus

Cladograms Depict patterns of shared characteristics among taxa Cladograms have branches. these represent different traits (characteristics) The closer branches are on the cladogram, the more shared characteristics the organisms on those branches will have. Closer branches = more related The more traits an organism has in the cladogram, the more evolved it is Primitive  Advanced

Impact of New Information Taxonomy is in flux Current system = 3 Domain system Bacteria Archaea Eukarya

Three Domains Bacteria and Archaea Eukarya Prokaryotic organisms, but different lineages Eukarya Eukaryotic organisms

Characteristics of the Domains Bacteria Archaea Eukarya Nuclear Envelope No Yes Membrane-bound organelles Introns Histone proteins associated with DNA Circular chromosome