Location of Hominid fossils worldwide

THE AREAS OF THE WORLD HOMINIDS AND OTHER ANIMALS ARE FOUND IN TODAY MAY SOMETIMES BE VASTLY DIFFERENT THAN IN THE PAST DUE TO CONTINENTAL DRIFT, POLE SHIFTS, AND GLOBAL WARMING/COOLING. THESE ENVIRONMENTAL FACTORS PLAY A KEY ROLE IN EVOLUTION….

Early Vertebrate Evolution

Definition of Species• The biological species concept emphasizes interbreeding and

reproductive isolation• Depiction of species as groups of individuals capable of interbreeding,

but reproductively isolated from other such groups.

species

This is a Cladogram

hybrids

Speciation

• Process by which a new species evolves from a prior species.

• Speciation is the most basic process in macroevolution.

Fossils• Many remains of the hominid species

are found in the form of Fossils• These are traces of ancient organisms

and formed in several ways• Mineralization occurs very slowly as

water carrying minerals, such as silica or iron, seeps into the tiny spaces within a bone. In some cases, the original minerals within the bone or tooth can be completely replaced.

• Traces of life forms that include insects trapped in tree sap, leaf imprints, footprints, skeletal remains and remains of digestive tracts

Interpreting Species and Other Groups in the Fossil Record

• The goal is to make meaningful biological statements about the variation represented in groups of organisms.

• Identifying individual variation, age changes, variation due to sex (sexual dimorphism)

• Fossil species are understood based on observations of living animals

• In living animals, we can look for variation both among and between species to try and explain fossils…