Zoology Notes #1

1. Zoology Notes #1 Intro and Classification

2. Zoology Unit Essential Questions • How have the designs of organisms changed throughout evolution? • Why are there similarities and differences in the design of organisms? • What explains the evolutionary relationships among organisms?

3. Evolution: Recap • small-scale evolution (changes in a population from one generation to the next) • large-scale evolution (the descent of different species from a common ancestor over many generations). • Evolution is descent with modification. • Evolution helps us to understand the history of life. • Biological evolution, simply put, change over time.

4. Central Idea for our unit • Central idea: • in biological evolution all life on Earth shares a common ancestor • just as you and your cousins share a common grandmother. • Looking at, comparing, and categorizing all organisms help us understand the relation between species (living and dead) • Classification Systems • Linnaean (Binomial Nomenclature) • Cladistics (Phylogenetic Tree)

5. Linnaean System: Old • Classifies organisms following: • kingdom, phylum, class, order, family, genus, and species • created before scientists understood that organisms evolved. • biologists are switching to a classification system that reflects the organisms' evolutionary history. • Still use the genus species to name organisms

6. Cladistics: New System Based on evolution reconstruct evolutionary relationships and represent them on a "family tree," called a phylogeny. Fossils and living specimen are used as evidence to create the trees

7. Phylogenies • A Tree/Phylogeny is a hypothesis of relationships among organisms • Organisms are grouped in clades • Clade: A group of organisms that includes all the descendants of a common ancestor and that ancestor.

8. “Tree of Life” all of life is related and can be divided into three major clades, often referred to as the three domains: Archaea, Bacteria, and Eukaryota.