introduction: describe trends in human evolution as 90719 level 3 – 3 credits
TRANSCRIPT
Introduction: Describe trends in Human Evolution AS 90719
Level 3 – 3 Credits
Keywords: Ape Dentition Australopithcine Dexterity Gracile Zygomatic Arches Robust Bipedalism Hominid Prognathism Hominins Foramen Magnum Primate Domestication Nomadic Arboreal Brachiation Quadrupedal 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.”
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
Order Suborder Infraorder Superfamily Family Examples
PRIMATES
Prosimii(prosimians)
Plesiadapiformes(archaic primates)
extinct plesiadapiformes(Purgatorius)
LemuriformesLemuroidea Lemuridae
Indriidaelemurindri
Adapoidea Adapidae extinct adapiformes
Lorisiformes Lorisoidea Lorisdae loris, galago (bush baby)
Tarsiiformes TarsioideaTarsiidae tarsier
Omomyidae extinct omomyiformes
Anthro-poidea
(simians or anthropoids)
Platyrrhini(New World
simians)
Ceboidea(New World Monkeys)
Callitrichidae marmoset, tamarin
Cebidae(true monkeys)
cebus monkey, spider monkey, howler monkey, capuchins, owl
monkey, sakis
Catarrhini(Old World Simians)
Cercopithecoidea
(Old World Monkeys)
Cercopithecidaecolobus, langurs, macaque,
baboon
Hominoidea(apes and humans)
Oreopithecidae extinct Oreopithecus
Hylobatidae gibbon, siamang
Pongidaeorangutan, gorilla, chimpanzee,
bonobo
Hominidae Homo sapiens, extinct Australopithecines
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 ridgesVision (Binocular)NostrilsSnout 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