Introduction: Describe trends in Human Evolution AS Level 3 – 3 Credits

Keywords:  ApeDentition  AustralopithcineDexterity  GracileZygomatic Arches  RobustBipedalism  HominidPrognathism  HomininsForamen Magnum  PrimateDomestication  NomadicArboreal  BrachiationQuadrupedal  Phylogeny

What we will cover:  Identifying the characteristics of Hominins and Hominids.  Describe patterns of evolution, human lineage (characteristics and trends) and dispersal.  Changes in hominin habitat due to selection pressures.  Inferences that have been made from anthropologic evidence.  Evolution and the key ideas that are used to formulate the theory of evolution.

Evolution:  Evolution is the process where different kinds of living organisms have gradually developed and diversified, from earlier forms.

The Evolution of Humans.  “The evolutionary design of man has intrigued humans for many years. It has lead anthropologists to travel the world in search of fossil evidence to learn who we have evolved from. Human evolution began roughly 5-10 million years ago when the human line split from the apes. Slowly scientists have tried to put the pieces together to give us an idea of our evolutionary line.” Human evolution began roughly 5-10 million years ago when the human line split from the apes. Slowly scientists have tried to put the pieces together to give us an idea of our evolutionary line.”

Classifications of Humans:  Kingdom – Animalia  Phylum – Chordata  Class - Mammalia  Order - Primates  Family – Hominidae (Hominids)  Genus - Homo  Specie - sapiens

Hominins vs Hominids  Hominins: living or fossil species of the human lineage. –Hominins are species that have contributed to the evolution of humans or are included in the human phylogeny –Examples: Australopithecus afarensis, Homo Habilis  Hominids: are humans and African apes –Hominids are species that currently exist (or recently extinct) and are identified as being Human or part of human phylogeny. –All hominids are endangered except humans –Examples: Bonobo, Gorilla and Chimpanzee’s

Hominids Hominins

Human Lineage  Humans are a relatively young species in geological terms. The earliest known humans date back approximately 170,000 years ago.  The development of the human species is often depicted as a straight line from Apes to Humans, this is not correct.

Common Depiction of Human Evolution from the 1960’s A more accurate depiction of Human Evolution

Back to the beginning: Primates  Humans are currently one of 200 Primate species that inhabit earth today.  Primates are classified using a series of distinct physical features that can be identified.

Primates

OrderSuborderInfraorderSuperfamilyFamilyExamples PRIMATESPRIMATES Prosimii (prosimians) Plesiadapiformes (archaic primates) extinct plesiadapiformes (Purgatorius) Lemuriformes Lemuroidea Lemuridae Indriidae lemur indri Adapoidea Adapidaeextinct adapiformes Lorisiformes Lorisoidea Lorisdaeloris, galago (bush baby) Tarsiiformes Tarsioidea Tarsiidaetarsier Omomyidaeextinct omomyiformes Anthro- poidea (simians or anthropoids) Platyrrhini (New World simians) Ceboidea (New World Monkeys) Callitrichidaemarmoset, tamarin Cebidae (true monkeys) cebus monkey, spider monkey, howler monkey, capuchins, owl monkey, sakis Catarrhini (Old World Simians) Cercopithecoide a (Old World Monkeys) Cercopithecidae colobus, langurs, macaque, baboon Hominoidea (apes and humans) Oreopithecidaeextinct Oreopithecus Hylobatidaegibbon, siamang Pongidae orangutan, gorilla, chimpanzee, bonobo Hominidae Homo sapiens, extinct Australopithecines Human classificationExtinct lineage

Primate Characteristics  List as many features you believe Primates display (physically and socially): – – – – – –

Social Features -Superior intelligence -Often complex social behavior -A highly developed problem solving ability - Use of a variety of communication methods

Physical Features - -Tail anatomy -Skull anatomy, including: Brow ridges Vision (Binocular) Nostrils Snout and lips -Limb length -Hand and foot anatomy + nails instead of claws

Adaptive Radiation in Primates

Primate Groups

New & Old World Monkeys

Old World monkeys  Africa & Asia  Arboreal and ground dwelling  No prehensile tail  Nostrils open downward  Diurnal  Live in bands- very social New World monkeys  South America  Arboreal  Prehensile tail  Nostrils open to the side  Diurnal  Live in bands- very social

Primate Locomotion  Primates can be broken into two main groups based on locomotion. –Arboreal –Ground dwelling

Arboreal  Locomotion of Primates who live primarily or permanently among trees.  It can be classified into more detailed groupings –Quadrupedalism –Modified Quadrupedalism –Brachiation

Arboreal Quadrupedalism  Walk on all four limbs along tree branches  Arms and Legs are almost equal in length  Example: Lemurs

Modified Quadrupedalism  Main mode of transport is leaping and clinging  Prefer to move along vertical trunks  Examples: Prosimians

Brachiation  Using arms to propel through trees  Full brachiation (use only arms)  Example: Gibbons  Semi-brachiation (hind limbs)  Example: Spider monkey  ( Likely precurser to quadrapedalism and bipedalism )

Ground Dwelling  Locomotion that occurs on the ground using the following methods –Quadrupedalism  Using all four limbs at once  Example: baboons –Knuckle-walking  Support using their hands specifically their knuckles  Example: chimpanzees and gorillas –Bipedalism (habitual)  Walk only on hind legs all of the time  Example: hominids, humans