Overview
This topic explores the system used to classify living organisms and the evolutionary history of humans. It includes taxonomy, domains and kingdoms, and major milestones in hominid evolution supported by fossil and genetic evidence.
Key Concepts and Structures
- Taxonomy: The science of naming and classifying organisms. Developed by Carl Linnaeus using a hierarchical structure and binomial nomenclature (Genus species).
- Hierarchical Classification: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species ("Dear King Philip Came Over For Great Spaghetti").
- Three Domains: Archaea, Bacteria (prokaryotic), and Eukarya (eukaryotic organisms including plants, animals, fungi, and protists).
- Evolutionary Relationships: Determined using morphological traits, embryology, and molecular data (e.g., DNA and protein sequences).
- Phylogenetics: The study of evolutionary relationships based on shared derived characteristics. Phylogenetic trees show common ancestry.
- Cladistics: A method of classification based on shared evolutionary history. Groups organisms into clades based on derived traits.
- Hominid Evolution: Refers to the evolutionary history of the family Hominidae, including modern humans, Neanderthals, and early ancestors.
- Human Ancestors: Notable genera include Australopithecus (e.g., Lucy) and Homo (e.g., Homo habilis, Homo erectus, Homo sapiens).
- Key Traits in Human Evolution: Bipedalism, larger brain size, tool use, and complex language and social behavior.
- Fossil and Genetic Evidence: Supports shared ancestry and tracks divergence from common ancestors with other primates. Mitochondrial DNA has been useful for tracing maternal lineage.
Quick Tip
Know the order of taxonomic ranks and how to read a phylogenetic tree. Be familiar with key fossils like "Lucy" and what traits distinguish modern humans from early ancestors.