How Anthropologists Group the Early Hominids - dummies

How Anthropologists Group the Early Hominids

By Cameron M. Smith, Evan T. Davies

Part of Anthropology For Dummies Cheat Sheet

By studying early hominids (large, bipedal primates) that date back to millions of years, anthropologists can track the development of the human race. When exploring anthropology, ‘keep these important points in mind:

  • The evolutionary process shapes species by replication, variation, and selection, leading to adaptation.

  • Humans are one of roughly 200 species of the Primate order, a biological group that’s been evolving for about 60 million years.

  • Hominids appear (only in Africa) by at least 4 million years ago with the following adaptive characteristics: bipedalism (habitually walking on two legs), encephalization (larger brains than expected for their body size), small teeth (smaller teeth than expected for their body size — the canines in particular).

The following table summarizes what anthropology has discovered about the main groups of early hominids.

Hominid Group, Diet, and Tool Use Some Genera and Species Included Fossil Finds Dates Evolutionary Fate
Gracile australopithecines: omnivorous diet with little tool
Australopithecus afarensis, Australopithecus
A. afarensis in Ethiopia, and A. africanus at
many sites in South and East Africa
Over 4 million years ago (A. afarensis) to about 2
million years ago (later A. africanus)
A. afarensis probably ancestral to A. africanus;
A. africanus probably ancestral to early Homo
Robust australopithecines: more herbivorous diet with little or
no tool use.
Australopithecus aethiopicus, Australopithecus
A. aethiopicus and A. boisei in East Africa,
A. robustus in South Africa
Over 2 million years ago (A. aethipoicus)
to about 1 million years ago (late A. robustus)
Extinction around 1 million years ago
Early Homo: omnivorous diet with more animal tissue
consumption and survival relying on tool use.
Homo habilis, Homo rudolfensis, earliest Homo
Olduvai Gorge, Tanzania and Koobi Fora, Kenya Earliest Homo around 2.5 million years ago; clearly
H. erectus by 1.8 million years ago
Evolved into H. erectus by 1.8 million years ago