Human Evolution

Primates The order Primates includes humans, apes, monkeys, and prosimians. Some taxonomic splitters classify up to 350 species, while lumpers include as few as 190.  Most estimates are in the range of 230-270. Natural Range of Non-Human Primates

Primates

Primate Characteristics Grasping limbs, with long fingers and separated opposable thumb

Primate Characteristics Mobile arms, with shoulder joints allowing movement in three planes

Primate Characteristics Stereoscopic vision, with forward facing eyes giving an overlapping field of view

Primate Characteristics Skull and hips modified for upright posture

Taxonomic Classification of Humans Kingdom Animalia Phylum Chordata Class Mammalia Order Primates Family Hominidae Genus Homo Species sapiens

Family Hominidae Includes the extant genera… Homo – humans Pan – chimpanzees Gorilla – gorillas Pongo - orangutans

Fossil Evidence of Extinct Hominids ‘Lucy’ – Australopithecus afarensis 40% complete skeleton Discovered in1974in Ethiopia’s Rift Valley Estimated 3.2 million years old, and 3.6 feet tall

Fossil Evidence of Extinct Hominids Laetoli Footprints Estimated Date: 3.6 million years ago Prints of adult and child walking through volcanic ash Found in Great Rift Valley

The Fossil Evidence of Hominid Evolution is Limited

Transitional Fossils In Hominid Evolution

Trends in Hominid Evolution Increasing brain size in relation to body size

Hominid Diets and Brain Size Early hominid skulls display large powerful jaws, indicating a vegetarian diet. Over time, fossils show an increase in brain size, correlating to discovery of tools.

Hominid Diets and Brain Size Meat contains more energy, allowing increased growth of brain size Greater intelligence would make for a significant hunting advantage

Trends in Hominid Evolution Increasing adaptation to bipedalism

Cultural Evolution Does not involve changes in allele frequencies in gene pools Can occur within a individual’s lifetime Includes language, tool making skills, hunting techniques, agriculture, religion, art, etc. Currently our cultural evolution is far outpacing genetic evolution