The unity and diversity of life
An Understanding by Design Unit
For AP Biology
Sharon High School
Teacher: James Dixon

This Wikipedia has been created by the AP Biology students of Sharon High School. The AP curriculum requires a great breadth of knowledge about the diversity of life. Students must develop an understanding the levels of classification, the use of classification schemes, the species concept, and the diagnostic characteristics of the various major taxa of life. This last area is a particular problem. The students come in with very little background and the coverage of the material is broad but not deep. At its worst, it can be just a list of characteristics. At its best, we can examine the strategies in which all the taxa of life face common problems of existence.
This assignment is part of a unit on the unity and diversity of life and provided a means to address the topic of the characteristics of the taxon. Each student was assigned a particular taxa. The student used the textbook as a source and prepared the page for the taxon including basic information about each topic. Students then had to edit the pages. Each student was required to supply one edit per page. They were to add information from internet sources and supply the links. Each student was allowed to supply up to 5 pictures (up to one per page) and up to 5 review questions (up to one per page). This editing process required the students to read each page and research the taxon for more information. In this way, the students were each developing some deeper knowledge about one taxon and familiarity with the other taxa. While this is not ideal for a zoology or botany class, it is the correct level of understanding for the AP Biology curriculum.
During this process of entering information and editing, I was able to monitor the students’ work by checking the history for the wiki. The students were also able to easily email me and each other. While anyone can view these pages, only students in this course have permission to write or edit on this wiki. I asked students to initial any edits. The topics for each taxa and the assessment rubric are included as pages on the wiki. While the students worked on the wiki mostly at home, we used class time to examine the definition of species through a case study and work with phylogenetic trees and relationships.

Established Goals:
AP Biology Themes (all addressed in part):
I. Science as a Process
II. Evolution
III. Energy Transfer
IV. Continuity and Change
V. Relationship of Structure to Function
VI. Regulation
VII. Interdependence in Nature
VIII. Science, Technology, and Society
2.3 Use cellular evidence (such as cell structure, cell number, and cell reproduction) and modes of nutrition to describe six kingdoms (Archaebacteria, Eubacteria, Protista, Fungi, Plantae, Animalia).
4.8 Recognize that the body’s systems interact to maintain homeostasis. Describe the basic function of a physiological feedback loop.
5.1 Explain how evolution is demonstrated by evidence from the fossil record, comparative anatomy, genetics, molecular biology, and examples of natural selection.
5.2 Describe species as reproductively distinct groups of organisms. Recognize that species are further classified into a hierarchical taxonomic system (kingdom, phylum, class, order, family, genus, species) based on morphological, behavioral, and molecular similarities. Describe the role that geographic isolation can play in speciation.
5.3 Explain how evolution through natural selection can result in changes in biodiversity through the increase or decrease of genetic diversity from a population.

Essential Questions:
· How can we use categorization and hierarchical thinking to make sense of the vast diversity of living species?
· How can different anatomical and physiological strategies help organisms meet the same challenges of life?
· How can the concept of definition be applied to the species concept?
· Does our organizational system for the diversity of life imply evolutionary relationship?
· Organisms are placed in various taxa based on diagnostic characteristics.
· Evolutionary relationships can be implied but not proven by classification.
· Classification is based on human decisions.
· The definition of species is problematic.
· All organisms face similar challenges of life but employ a wide array of anatomical and physiological strategies to meet these strategies.
· These strategies are based on environment and evolutionary history.
Students will know:
· The various levels of phylogenetic organization.
· How diagnostic characteristics are used to organize organisms into categories.
· The various definitions for species and the problems with each.
· Explain the various modes of speciation.
· Explain the various modes of reproductive isolation.
· Describe how evolutionary relationships are determined by using various forms of evidence.
· The diagnostic and other important characteristics of selected major taxa.

Students will be able to do:

· Interpret phylogentic trees and cladograms.
· Apply genetic, morphological, ecological and behavioral evidence to classifying organisms and determining evolutionary relationships.
· Write to and edit wiki pages

Performance tasks:
· The Unity and Diversity of Life Wikipedia project

Other evidence:
· Unit exam
· Creating and interpreting cladograms activity
· “What is a species?” case study/web quest

Learning plan (for approximately 10 classes):
· Discussion of classification conundrums (vultures, slime molds etc.).
· Computer lab for wiki intro and set-up.
· Discussion of cladograms and phylogenetic trees.
· Cladogram activity.
· “What is a species?” case study/web quest (3 classes).
· Discussion of speciation and reproductive isolating mechanisms.
· Evidences for evolution and evolutionary relationships.
· Sharing of wiki pages.
· Unit exam.

The taxa and the topics for each are as follows:
Kingdom level:
1. Archaea
For the kingdoms the characteristics that should be examined are:

· Diagnostic characteristics of the group
· Habitats
· Major types
· Basic anatomy
· Transport of materials
· Reproduction
· Environmental adaptations

Kingdom Plantae
5. Plantae--Mosses
6. Plantae--Ferns
7. Plantae--Gymnosperms
8. Plantae—Angiosperms
For the Plant groups the characteristics that should be examined are:
· Diagnostic characteristics of the group
· Habitats
· Major types
· Basic anatomy
· Transport of materials
· Reproduction
· Environmental adaptations

Kingdom Animalia:
9. Porifera
10. Cnidaria
11. Platyhelminthes
12. Nematoda
13. Mollusca
14. Annelida
15. Arthropoda--Insecta
16. Arthropoda--Crustacea
17. Echinodermata
18. Chordata –2 invertebrate subphyla
19. Chordata--Fishes
20. Chordata--Amphibia
21. Chordata--Reptilia
22. Chordata--Aves
23. Chordata--Mammalia
For the animal groups:
The characteristics that should be examined are:
· The diagnostic characteristics that define the group
· Acquiring and digesting food
· Sensing the environment
· Locomotion
· Respiration
· Metabolic waste removal
· Circulation
· Self protection
· Osmotic balance
· Temperature balance