The ability to adjust to a variety of different habitats and environments is a characteristic of humans. The ability to move and track habitat change geographically (narrow lines) or to expand the degree of adaptive versatility is important for any lineage to persist.Extinction occurs if species populations have specific dietary/habitat adaptations (i.e., a narrow band of ‘adaptive versatility’; highlighted bands) and cannot relocate to a favored habitat.
Over the course of human evolution, human ancestors increased their ability to cope with changing habitats rather than specializing on a single type of environment.
Icons: (a) hominin origins, (b) habitual bipedality, (c) first stone toolmaking and eating meat/marrow from large animals, (d) onset of long-endurance mobility, (e) onset of rapid brain enlargement, (f) expansion of symbolic expression, innovation, and cultural diversity.
All organisms encounter some amount of environmental change.
Hominin fossils would be found in those environments and not present in diverse types of habitat.
A different hypothesis is that the key events in human evolution were shaped not by any single type of habitat (e.g., grassland) or environmental trend (e.g., drying) but rather by environmental instability. Rick Potts of the Human Origins Program, is called variability selection.