Students should be able to:
The essence of systematics or taxonomy is embodied in the appreciation of evolutionary relationships amongst the more than 1.5 million biological species already known to man. Systematists seek to understand the diversity of life, and to reconstruct the evolutionary or phylogenetic relationship amongst the different kinds of organisms that lived in the past or are currently cohabiting the earth.
Systematists traditionally use evidences derived from fossil record and morphological and anatomical studies of extant organisms to reconstruct phylogeny. Today, molecular biology such as amino acid sequences of proteins and nucleotide sequences of DNA and RNA, provide powerful tools for systematics.
The concept of Cladistics was pioneered in 1950 by a German entomologist named Willi Hennig, who published a short book in which he proposed the basic ideas that changed taxonomy. The term Cladistics takes its name from the concept of a "clade", which Hennig defined as a group of organisms related by common descent.
The objective of cladistics is to classify organisms according to their evolutionary relationships, and that the way to discern these relationships is to determine what characters are primitive and which are considered derived characters. The former are those attributes of an organism, which all members of the group have in common to one another. Commonly shared or primitive characters shared by all members of the group in question are called symplesiomorphic.
Derived characters are relatively recent in evolutionary appearance, and are also considered advanced traits that only appear in a few members of the group. Cladistics taxonomy makes the assumption that the appearance of derived characters may provide information to evolutionary relationships.
This section is intended to guide student towards a brief but meaningful survey of relevant taxonomic literature. It should be useful in helping you appreciate the purpose of the exercises involved in the following sections.
Pre-Laboratory Activity #1 - Linne Biography
Click on Access Science (from the LRC Homepage) and find a biography of Carl von Linné. Print it out, read it, it will help you with your Pre-Lab Questions. Attach it to your Pre-Lab Questions
Pre-Laboratory Activity #2 - Sample Dichotomous Key
Pre-Laboratory Activity #3 - Data Collection Sheet
Pre-Laboratory Activity #4 - Using Dichotomous Keys
Dichotomous keys are useful for rapid and correct identification of various species. You will be using two keys, one for plants and the other for animals. The first is a dichotomous key for some common trees in the winter condition. The second is a pictorial key for the identification of fleas. Download and print out all of the following:
The Laboratory Activities and Data Collection
Lab Activity #1 - Species Description
Lab Activity #2 - Species Classification
Lab Activity #3 - Using Dichotomous Keys - Plants
Lab Activity #4 - Using Dichotomous Keys - Animals
Lab Activity #5 - Constructing a Simple Dichotomous Key
Lab Activity #6 - Cladistics
Post-lab Activity and Data Analysis
Results and Analysis
Below are listed the activities you performed in lab and the results and analysis materials that are to be given to the instructor.