Lab 9 Flashcards
KNM-ER 1470 & KNM-ER 1813
Two early Homo fossil specimens central to debates over species classification; used to explore whether they represent the same or different species.
Comparative Anatomy
The study of similarities and differences in anatomical features across species to assess variation and determine species identity.
Flintknapped Tool
A human-made stone tool produced by striking a rock with another stone (hammerstone) to detach flakes.
Striking Platform
The flat area on a stone core where a blow is struck to remove a flake.
Point of Percussion
The exact spot where a hammerstone hits the core to initiate flake removal.
Bulb of Percussion
A raised area on a flake that shows the force of the blow used to remove it from the core.
Cortex
The rough outer surface of a stone core, often remaining on initial flakes.
Dorsal Surface
The outer surface of a flake (that faced outward on the original stone).
Ventral Surface
The inner surface of a flake, created by the fracture from the core.
Core
The original rock from which flakes are removed; may be used as a tool itself.
Flake
A piece struck off a core with a sharp edge, used for cutting or scraping.
Retouched Flake
A flake that has been further shaped or sharpened by removing tiny flakes from its edge.
Oldowan Technology
The earliest known stone tool tradition, marked by simple flake and core tools (~2.6 mya).
Intra-species Variation
Variation within a single species due to age, sex, health, region, etc.
Inter-species Variation
Variation between different species, often more pronounced.
Lumpers vs. Splitters
“Lumpers” group fossil specimens into fewer species based on variation; “Splitters” interpret variation as evidence for more species.
Standard Deviation (SD)
A statistical measure of the amount of variation or dispersion in a dataset.
Variance
The average of the squared differences from the mean; the basis for standard deviation.
Coefficient of Variation (CV)
A scale-independent measure of variation (SD divided by the mean × 100), used to compare variation across traits or species.
Sexual Dimorphism
Differences in size and physical traits between males and females of the same species.
Supraorbital Torus
A bony ridge above the eye sockets, often more prominent in males.
Temporalis Muscle
A muscle involved in chewing; its size (inferred from skull features) is often larger in males.
Species Concept (Biological)
Defines a species as a group of organisms capable of interbreeding and producing fertile offspring.
