the human story - lrr.cli.det.nsw.edu.aulrr.cli.det.nsw.edu.au/legacy/science/43207_p1.pdf · the...

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BiologyHSC CourseStage 6

The human story

Part 1: Classification

Incorporating October 2002

AMENDMENTS

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Part 1: Classification 1

Contents

Introduction ............................................................................... 3

Classification ............................................................................. 5

The species concept ............................................................................7

Primate characteristics.........................................................................9

Primate classification............................................................... 17

The prosimians...................................................................................18

Anthropoids ........................................................................................24

Hominids.............................................................................................29

Hominins.............................................................................................37

Human classification ............................................................... 39

Human characteristics .......................................................................43

Dispute in classification......................................................................45

Hominid vs hominin debate ...............................................................48

Similarities and differences in primates ................................... 49

Observing primates ............................................................................49

Summary................................................................................. 71

Suggested answers................................................................. 73

Exercises – Part 1 ................................................................... 77

2 The human story

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Introduction

The human story starts with the classification of humans. We are a groupof primate mammals and we share characteristics with other groups.What features make us animals, chordates, mammals, primates andfinally human? An examination of the primate groups highlights ourrelationship to this group. By looking at our closest relatives we can gainan insight into our evolutionary relationships.

In this part you will be given opportunities to learn to:

• outline the general classification hierarchy from phylum to species

• define the term species and outline criteria used to identify a species

• outline features that classify humans as:

– mammal

– primate

– hominid

– hominin

• discuss the use of the terms hominin and hominid in terms of thearbitrary nature of classification systems

• describe primate characteristics including:

– hand/foot structure and function, including opposable thumb ortoe

– skull shape and function

– brain size relative to body size

– arrangement of the vertebral column to the degree of uprightstance

– vision, including degree of stereoscopic vision, colour vision

– reproductive features, including single live young and relativelylong gestation

– parenting and group bonding

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• describe primate characteristics in

– prosimians

– new and old world monkeys

– apes

– humans

In this part you will be given opportunities to:

• identify data sources, gather, process and analyse information fromsecondary sources to illustrate the classification process byidentifying features of humans that classifies them as:

– Animal

– Chordate

– Mammal

– Primate

– Hominid

– Homo

– Homo sapiens

• analyse information and use available evidence to identify technologicaladvances and resulting new information that have changed scientists’opinions about the classification of primates

• process information to summarise and analyse the similarities anddifferences between prosimians, monkeys, apes and humans.

Extract from Biology Stage 6 Syllabus © Board of Studies NSW, originallyissued 1999 modified November 2002. The most up-to-date version can befound on the Board's website athttp://www.boardofstudies.nsw.edu.au/syllabus_hsc/syllabus2000_lista.html

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Classification

Classification is the process of sorting like with like. The study ofclassification is called taxonomy. It is an arbitrary system invented byhumans to enable clearer communication. There are many features thatcould be chosen to separate one group from another. Scientists havefound that using structural features of animals and plants helps tocategorise them and show evolutionary relationships. If animals aregrouped closely together then this indicates that they share a commonevolutionary pathway.

You will recall from the Preliminary course that the classification systemhas various levels. The broadest separation is at the kingdom level.At this level, all living things are divided into five kingdoms. There areother ways of separating the major groups but for this module you willuse the classification below.

• Kingdom Monera (prokaryotic organisms eg. bacteria andcyanobacteria)

• Kingdom Protista (single celled organisms eg. algae and protozoa)

• Kingdom Fungi (yeast, toadstools, mushrooms)

• Kingdom Plantae (plants)

• Kingdom Animalia (animals)

The kingdom level is the first level of classification.The animal kingdom is divided into around forty phyla (singular,phylum). Each phylum is further divided into class, order, family, genusand species.

The table following shows how some common animals are classified.

The final classification levels are the genus (plural, genera) and species.These last two names make up the binomial name for each species.For example, Homo sapiens is the binomial name for humans. It consistsof the generic name Homo and the specific name sapiens. When youreach the species level of classification the members are so alike that theycan breed and produce fertile offspring.

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Classification level Dog Cat Grey kangaroo

Kingdom Animalia Animalia Animalia

Phylum Chordata Chordata Chordata

Class Mammalia Mammalia Mammalia

Order Carnivora Carnivora Diprotodonta

Family Canidae Felidae Macropodidae

Genus Canis Felix Macropus

Species familliaris domesticus Giganteus

Looking at the classification of the dog, cat and kangaroo in the table abovegives useful information on their evolutionary relationship. Decide whichtwo animals are the most closely related and give a reason.

_________________________________________________________

_________________________________________________________

_________________________________________________________

Check your answer.

A further separation of classification can be achieved with the addition ofsuper and sub to the levels. For example Subphylum and Superfamily.

The full classification for Homo sapiens follows.

You are expected to know the classification of the human species so takea few minutes now to learn the first two columns of the table.

Do Exercise 1.1.

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Classification level Human Feature at this level

Kingdom Animalia heterotrophic, no cell wall, mobile

Phylum Chordata have a notochord or dorsal nerve tube

Subphylum Vertebrata backbone

Class Mammalia hair, mammary glands, specialisedteeth, four chambered heart, lower jawcomposed of only one bone

Order Primates opposable thumb, nails, binocularvision, forward directed eyes, twonipples

Family Hominidae arms shorter than legs, upright stance,

Genus Homo bipedal gait, erect posture, S-shapedspine, foramen magnum facing down

species sapiens large brain, speech, complex socialsystem

The species concept

The term species comes from Latin and means ‘kind’. A definition of aspecies is shown below.

A group of actually or potentially interbreeding natural populationsthat is reproductively isolated from other groups.

As with nearly all definitions there are exceptions to the rule.The classification of organisms is based on morphology or structure.Some of these groups can breed under unusual circumstances to formhybrids. Examples of hybrids formed between different species are:

• sterile hybrids

• fertile hybrids

• captivity hybrids

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Sterile hybrids

You may have heard of the hybrid that is formed between a female horseand a male donkey. This offspring is a mule. Mules are used extensivelyas pack animals because of the features that they inherit from bothparents. Mules are always sterile and cannot produce offspring.Each mule has to be bred from a horse and a donkey. The horse has64 chromosomes and the donkey has 62 chromosomes. The resultantmule has 63 chromosomes. The two species are reproductively isolated.

Fertile hybrids

There are examples of organisms that have been classified in differentgroups based on their structural features that have bred together andproduced hybrid species that can reproduce. Examples of this can beseen amongst native plant species such as eucalypts and banksias.Banksia aspleniifolia and Banksia robur hybridise when they occurclosely together and produce fertile offspring with intermediatecharacteristics. This population with intermediate features iscalled a cline.

Banksia robur has large leaves covered with rusty coloured hairs.Banksia aspleniifolia is a small leafed plant not covered with red hairs.When these two species hybridise the range of leaf size and shapeincludes many intermediate forms as illustrated in the photograph below.

Variation in leaf shape and size showing the cline between Banksia robur andBanksia aspleniifolia.(Photograph: Jane West)

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Based on their morphology, the two species are very different.They also use resources differently. Banksia robur lives in swampyareas while Banksia aspleniifolia is a heath plant and lives in drier areas.Their classification based on morphology places them into two differentspecies. The fact that they hybridise and produce fertile offspringchallenges the definition of a species. Morphologically they are twodifferent species; genetically they are one. This is a good illustration ofthe arbitrary nature of classification.

Captivity hybrids

Other species would never breed in the wild but may breed in captivity,for example lions and tigers form ligers or tions. This makes it importantto include a mention of natural or wild populations in your definition of aspecies to exclude zoo hybrids.

Do Exercise 1.2.

Primate characteristics

You have looked at the classification system, now you will apply this tothe primate order.

What makes a primate?

Humans belong in the primate order along with the apes (gorillas,chimpanzees), the monkeys and the prosimians (lemurs and loris).Other primates have existed in the past and are now extinct.This group of animals is placed in the same group because they shared acommon ancestor in the Age of the dinosaurs (65 million years ago).Since then they have adapted to different environments.

The word primate comes from Latin and means ‘first’. As humans arethe species creating the naming system, we have made our group animportant one. The word primate also shares its meaning with the termsprime minister and premier.

Primates share many characteristics but in some ways have anunspecialised body shape. Primates are mammals so they share thebiological and behavioural features of mammals.

Mammals control their body temperature within a prescribed range usinga complex system including heat retention and heat loss. This is helpedby glands and body coverings such as skin and hair.

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Mammals have an efficient breathing system, a separate chest andabdominal cavity, a four-chambered heart and a complexnervous system.

Mammals require a lot of food to maintain body temperature.The reproductive period is long and the mother nourishes the childduring this period. Mammals have a range of behaviour and require aperiod of learning to achieve adult behaviour.

In contrast to the features which primates share with mammals, theprimates have maintained the collarbone. They have unspecialised teethand the snout is reduced as is the part of the brain that deals with thesense of smell.

Primates have no feature that every member possesses. It is more like acollection of similarities including:

• hand/foot structure

• skull shape and function

• relative brain size

• arrangement of vertebral column

• vision

• reproductive features

• parenting and group bonding

• retention of the clavicle

• a mobile shoulder joint allowing free movement

• usually two nipples.

Hand/foot structure

Usually primates have five flexible digits (pentadactyl). They have anopposable thumb and toe. The opposable digit is set at an angle to thefingers. This means that the thumb can move over and touch the fingersforming a strong grasp. The exceptions to this are humans who onlyhave opposable thumbs and spider monkeys which don’t have a thumb.

Most primates have nails instead of claws on at least some of the digits.They have the ability to hold and manipulate an object. They havesensitive pads on the digits. Primate hands can be used for gripping,climbing, running and for handling tools.

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hands

feet

tarsier orang-utan gorilla human

Hand and feet structure of a number of primates. Note the five digits and theopposable thumb/toe.

Activity: Grasping objects without a thumb

The opposable thumb allows objects to be manipulated with precision.Without your thumb many everyday activities become virtually impossible.Try the following activities after you tape your thumb to the rest ofyour fingers.

• Pick up a small object from the desk.

• Write your name.

• Turn over the page of a book.

Write a comment on the above activity. What did you learn about thesignificance of an opposable thumb?

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

The opposability of the thumb or toe allows for two important grips.One is the power grip and the other is the precision grip. The powergrip is the one that you would use to grab a branch and hold on tightly.The precision grip allows delicate movements such as threading a needle.The primates share the power grip but the precision grip is at its best inthe human hand.

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An opposable thumb allows primates to grip objects.

Skull shapes and function

The shape of the primate skull is based on function. It has to enclose alarge brain. Primates are smart. Their enlarged skull encases a largebrain. The large brain enables good motor development and sensoryskills and has two unique creases.

Primates have fewer teeth than many mammals. The cheek teeth ofprimates have low cusps which allows a flatter face. A flatter face is abenefit for depth perception. The flatter face is associated with a reducedsnout length and reduced sense of smell.

A distinctive middle ear structure with ears located on either side of theskull is another feature of primates.

The attachment of the skull to the backbone occurs at theforamen magnum.

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In apes this is towards the rear of the skull. In humans the skull attachesdirectly underneath so the head is upright.

brow ridge

canine

foramenmagnum

cranium

gorilla

brow- ridge

canine foramenmagnum

craniumhuman

Notice that the foramen magnum in the human is located centrally and is facingdownwards while in the gorilla it is towards the rear of the skull and is facingtowards the back.

Relative brain size

Primates have well developed brains. They possess a great ability tolearn. Primates have a large brain size relative to their body size.If you compare the brain size of similarly sized animals such as achimpanzee and a dog, the chimpanzee has a greater brain size relativeto its body.

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Arrangement of vertebral column

A tendency towards upright stance and an S-shaped spine is aconsequence of the move to bipedal locomotion. Primates have speciallyadapted vertebra and a broad pelvis.

Vision

Primates are characterised by large forward facing eyes that see incolour. The eyes are surrounded by bone. There is a field of viewoverlap because the eyes are facing forward. This leads to goodstereoscopic (binocular) vision.

Activity: Field of view overlap

Put a hand over your left eye and note how far to the left your right eye cansee. Then repeat this time using the right eye. See how far to the right yourleft eye can see. There is a large overlap between the two fields.

Estimate how much of an overlap there is in your field of view.

The slightly different angles between the two views give depthperception. This is important for jumping between tree branches.Many other mammals have eyes on the side of their heads. This is goodfor keeping an eye out for predators but, because the field of views donot overlap, there is less depth perception.

Lemur Human

Field of view overlap of a lemur and a human. Notice that the human overlap ismuch greater because of the flatter face.

Reproductive features

Primates give birth to live young. The gestation period is lengthy–up to40 weeks in humans, apes and gorillas. This reduces the number ofoffspring produced by a female in a lifetime.

Primates usually produce a single baby that is suckled from two milkglands on the mother’s chest.

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Young are dependent for a long period of time and much of theirbehaviour is learned and not instinctive. Overall, there is a lengthenedperiod of dependency. Most primates have a restricted breeding periodand have a cyclical sexual period.

Parenting and group bonding

The juvenile stage is long and there is a long period of learning.There are benefits to living in a group in terms of protection againstpredators and in gaining food. The group is the centre of socialinteraction with highly organised and complex relationshipsbetween individuals.

Do Exercise 1.3

16 The human story

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Primate classification

Primate classification is difficult and there are different ideas about therelationships between primates. The traditional classification is based onanatomical features; a more recent classification is based on geneticsimilarities and molecular evidence.

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The first diagram is the traditional classification based on morphology and thesecond diagram is based on genetic similarity.

The genetic information has led to a change in classification for theAfrican apes. They are no longer classified with the Asian apes but aremuch closer to humans.

Look at the diagram following of primate classification. This is one ofthe traditional classification schemes for primates. As you go througheach group, come back to this diagram and circle the group.

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0

10

20

30

40

50

60

Pliocene

Millions of years ago

RecentPleistocene

Miocene

Oligocene

Eocene

Paleocene

PrimitiveProsimians

New Worldmonkeys

Old Worldmonkeys

Gibbon Orangutan Gorilla Chimpanzee Human

Early Prosimians

Traditional grouping of primates.

The bodies of primates reflect their arboreal (tree-dwelling) origins.The dominant sense in primates is vision. Good depth perception isrequired to live in the trees and jump from limb to limb. You do notneed to look far into the distance because trees would block your view.Fingers have to grip branches so they need to be opposable.The sense of smell is important for locating ripening fruit.

The primates considered to be primitive still exhibit arboreal adaptationswhile those thought to be more advanced have adaptations for grounddwelling. Primates have retained the clavicle bone which is greatlyreduced or lost in most mammals.

The prosimians

The prosimians (before apes) are a group of lower primates consisting oflemurs, lorises, tarsiers and bushbabies. They are small nocturnal treedwellers with grasping hands and feet. They have flattened nails andforward facing eyes. They have pointed faces allowing for good depthperception but still allowing a good sense of smell.

The prosimian snout is reduced when compared to other mammals butstill interferes with the field of view. Except for tarsiers, which aredifficult to classify, prosimians have a wet nose (rhinarium). This is anadaptation for acute sense of smell. Prosimians occur in small isolatedpopulations and many are endangered. Three examples of prosimians arelemurs, tarsiers and lorises.

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The lemurs of Madagascar

Lemurs are found only on the island of Madagascar off the coast ofAfrica. Here they are under threat from logging and hunters.Madagascar is a small country and has to gain an income from itsnatural resources. Unfortunately, lemurs live in areas that are valuablefor timber.

The lemurs travel in groups that are all female or all male.The babies are all born at the same time whether they are in Madagascaror in Dubbo zoo. This increases the chances of survival of the young.Predators can only take so many of the young allowing some to survive.

Lemurs have a long snout, which is a primitive primate feature, but theydo have an opposable thumb and usually have nails. They have awell–developed sense of smell and use scent to mark their territory.They are omnivores.

A ring–tailed lemur showing the opposable digits and the short snout ofprosimians.(Photograph: © David Haring Duke University Primate Centre.)

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Close up of a white ruffed lemur face. Notice the forward facing eyes and moistnose (rhinarium).(Photograph: © David Haring Duke University Primate Centre).

Loris

These are found in tropical areas of South–east Asia. Lorises are similarto lemurs and are related to pottos and galagos (bush babies) of Africa.Lorises are slow and careful climbers.

Lorises lick the fur covering their bodies with unpleasant and poisonoussaliva to deter predators. They also lick their babies to protect them.

Lorises have a pointed face which is a primitive feature in primates.They have a solid build and live for ten years. They are active at night.They have a short tail that is hidden by fur.

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Slow loris. Look at the nails on the digits.(Photograph: © David Haring Duke University Primate Centre).

Tarsiers

Tarsiers are controversial animals in regard to their classification.Here the tarsiers are classified as prosimians. Other classificationschemes put them in a sub-order of their own the Tarsioidea.Tarsiers may be human’s closest relative outside of the apes.Some classifications put the tarsiers in with the Anthropoids (see later inthis part).

There is a similarity between nose and eye design, brain structure andbiochemical evidence. The tarsiers single surviving genus Tarsius live inlow lying forests on the South east Asian islands of Sumatra, Borneo,Sulawesi and Mindanao.

Tarsiers have a dry furry nose, huge eyes, big ears, short arms longflexible legs with long tarsal bones (thus the name), short nails but a longgrooming claw. They are nocturnal tree-dwellers.

They rely on vision and have a reduced sense of smell. Each eye islarger than its brain. They can rotate their heads similar to an owl andthis gives them 180° vision. They can leap up to two metres.

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Tarsier. Notice the large eyes and the presence of nails.(Photograph: ©Tim Knight Primate Gallery)<http://www.selu.com/bio/PrimateGallery>

Summary of prosimian features

• small nocturnal arboreal primates

• at least one digit has a nail instead of a claw

• more acute sense of smell than the other primates (use of scentglands)

• less opposable thumb than other primates

• grooming claws as well as nails

• eyes more to the side of the head than monkeys (less effectivebinocular vision)

• long snout with a wet tip (rhinarium)

• immobile face

• seasonal breeding.

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Look at the photographs of prosimians. For each example tick off theprosimian characteristics.

Name of prosimian Graspinghands andfeet

Flattenednails

Forwardfacing eyes

Aye–Aye.(Photograph: © David Haring DukeUniversity Primate Centre)

Sifaka.(Photograph: © David Haring DukeUniversity Primate Centre)

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Potto.(Photograph: ©Tim Knight PrimateGallery)<http://www.selu.com/bio/PrimateGallery>

Check your answers.

Anthropoids

The common ancestor for the anthropoids is thought to be an extinct apecalled Ramapithecus. This species of ape was found throughout Europe,Asia and Africa. They then branched into two main groups which thenled to the three groups: monkeys, apes and humans.

Features of anthropoids

Anthropoids:

• are generally larger than prosimians

• are mostly diurnal (active during the day)

• are generally tree dwellers

• have a brain size larger than the prosimians due to a larger cerebralcortex

• have a rounded skull

• have full binocular vision

• have bony plate at the back of the eye orbit forming an eye socket

• do not have a rhinarium (moist nose).

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Monkeys

Monkeys are divided into two groups:

• New world monkeys (from the Americas)

• Old world monkeys (from Asia and Africa).

It was thought that these groups evolved from different prosimians butamino acid sequencing has shown that they shared a common anthropoidancestor. Since this separation, monkeys have evolved down differentpaths. This is an example of how changing technology can change theclassification of organisms.

Differences between Old world and New worldmonkeys

There are three main differences between new and old world monkeys:the prehensile tail; the position of the nostrils; and the coloured buttockscalled callosities.

Feature Old world monkey New world monkey

prehensile tail absent present

nostrils pointing forward, shapedlike tear drops, closetogether

pointing sideways,nostrils round and wideapart

nose partition narrow wide

cheek pouches present absent

callosities common no

New world monkeys (Platyrrhini)

New world monkeys are limited to the tropical forests of southernMexico, Central and South America. These small to medium sizedmonkeys are arboreal (tree dwellers).

Most New world monkeys have a prehensile tail. A prehensile tail actslike a fifth limb and can wrap around branches. The prehensile tail has abare patch underneath. The patch has ridges like fingerprints and eachmonkey has a unique pattern.

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Some New world monkeys have a smaller thumb and spider monkeyshave the thumb missing. Their faces are different from Old worldmonkeys. Their noses are flattened and their nostrils open towards theside. They are social animals and live in groups. They are herbivorous.

Examples of New World monkeys

The most primitive monkeys are tamarins and marmosets.This group includes the Lion Tamarin below.

Lion tamarin. Notice the flattened nose and the nostrils opening sideways.(Photograph: © Tim Knight Primate Gallery)<http://www.selu.com/bio/PrimateGallery>

More advanced New World monkeys include squirrel monkeys,capuchins, howler and spider monkeys.

Spider monkeys live in the rainforests of the Andes. They live in thehighest part of the canopy. They are fruit and nut eaters (90% of theirdiet). They have a prehensile tail and their arms are longer than theirlegs. Their thumb is either small or does not exist. The hand is in a hookgrip to aid swinging through the trees.

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Photograph of spider monkeys. Note the prehensile tail being used as afifth limb.(Photograph: Jane West.)

Old world monkeys

Many Old world monkeys are sexually dimorphic. This means that themales and females look different and are different in size. Old worldmonkeys are arboreal except for baboons and macaques. The grounddwellers are quadrupeds (walk on four limbs). None of these monkeyshave a prehensile tail and some lack tails. Old world monkeys havethumbs that are fully opposable. Their nostrils are directed downwards.They are usually larger than New world monkeys. They are found in thetropical parts of Africa and Asia.

Old world monkeys are divided into two groups.

• Baboons, macaques, mandrills have cheek pouches and callosities.Callosities are hairless areas on either side of the rump. They areusually coloured. These monkeys are omnivorous.

• Proboscis monkeys, langurs and colobus are herbivorous monkeysthat feed on leaves.

28 The human story

Mandrill showing the sexual dimorphism that is often found in Old worldmonkeys. The male has a mane, a brightly coloured nose and is larger.(Photograph: ©Tim Knight Primate Gallery)<http://www.selu.com/bio/PrimateGallery>

The features to look for in an Old world monkey are:

• nails

• a shortened tail that is not prehensile

• diurnal

• opposable thumb

• nostrils directed downwards.

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Explain the meanings of the following terms:

prehensile tail _____________________________________________

arboreal __________________________________________________

opposable ________________________________________________

omnivores ________________________________________________

rhinarium ________________________________________________

nocturnal _________________________________________________

binocular vision ___________________________________________

callosities ________________________________________________

sexually dimorphic _________________________________________

bipedal __________________________________________________

quadrapedal _______________________________________________

Check your answers.

Hominoids

Apes and humans belong in the hominoid group. Hominoids have notails. They are larger than the New and Old world monkeys and have alarger brain. They have a complex system of social behaviour.They rely on sight rather than smell and have less pronounced muzzles.

There are five groups of hominoids: gibbons, orangutans, gorillas,chimpanzees and humans. They are classified as Hylobatidae, Pongidaeand Hominidae.

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The lesser apes (Hylobatidae)Gibbons and siamangs are known as the lesser apes. They are relativelysmall bodied and live mainly on fruit, some leaves and invertebrates.Males and females are about the same size.

They are found in the moist rainforests of Southeast Asia. They are veryacrobatic and move through the trees by a process called brachiating.If you have seen a gibbon swinging through trees going from hand tohand then this is what is meant by brachiating.

One arm supports the entire body weight. The arms are very long andreach the ground when standing upright. The hand acts as a hook forswinging. Gibbons are monogamous and mate for life which is unusualfor apes.

Gibbon. Notice the mobile shoulder joint and the opposable digits on bothhands and feet.(Photograph: © Tim Knight Wildlife Website) <http://www.selu.com/bio/wildlife>

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The great apes (Pongidae)

Orangutans

Orangutans also live in the trees. Their arms are long to make movementthrough the trees easy. They are found in Sumatra and Borneo.

Orangutans are a large ape and have long red-brown hair and a heavybody. They have an opposable thumb and big toe. The legs are muchshorter than the arms. Their diet consists mainly of fruit.

Orangutans reach sexual maturity between the age of eight and fifteen.The long period of maturation and dependence reflects the expansion ofthe juvenile period of learning.

They are diurnal and solitary. Orangutans rarely come down from thetrees. The infants stay with their mothers for 6 years and each female hastwo to three babies in a lifetime. Unlike the gibbon, there is a strikingdifference between the sexes (sexual dimorphism) with the malestwice as large as the females. The males develop large face andcheek pouches.

Male Orangutan with large cheek and face pouches.(Photograph: ©Tim Knight Wildlife Website)< http://www.selu.com/bio/wildlife>

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Hominids (Hominidae)

Hominids consist of the African apes (chimpanzees and gorillas) andhumans and their recent ancestors (Australopithecus, Paranthropus).

Gorilla

There are two forms of gorilla, both live in Africa – the mountain gorillaand the western lowland gorilla. They live mostly on the ground and arenot usually aggressive.

The gorillas are the largest of the primates with males reaching 200 kg.They are strict vegetarians. They rarely climb trees and walk on theirknuckles. Their arms are longer than their legs.

Gorillas are highly sexually dimorphic with females weighing 70–114 kgand males 160 kg. Males have large sharp canine teeth.

Mountain gorilla coats are silky, ranging in color from blue-black tobrownish-grey. Mature males develop silver or grey hair on their backs,giving them the name silverbacks. Gorillas live in groups from5–30 members. Each group has a dominant silverback male.The rest will be females and black-backed males.

Silverback male gorilla.(Photograph: Tim Knight © Gorilla's Online) <http://www.selu.com/bio/gorilla >

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Gorilla showing knuckle-walking and care of the young.(Photograph: ©Tim Knight Gorilla's Online) <http://www.selu.com/bio/gorilla>

Mountain gorillas occasionally eat invertebrates, but they are primarilyleaf eaters. They eat the roots, leaves, and stems of plants. Their diet issupplemented by small amounts of bark, wood, roots, flowers, fruit,fungi, and gorilla dung.

Reproductive rates are slow and a female will have only 2–6 offspring ina lifetime. A single, dependent young is born after eight and a halfmonth gestation period. Weaning often doesn’t occur until three years ofage, and juveniles may remain with mothers for years after that.

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Chimpanzees

Chimpanzee showing the position for knuckle-walking.(Photograph: ©Tim Knight Primate Gallery)<http://www.selu.com/bio/PrimateGallery.>

There are two species of chimpanzee both of which live in tropicalAfrica, the chimpanzee and the bonobo or pygmy chimpanzee.They spend much of their time in the trees but when they return to theground they do walk on two feet although the usual method oflocomotion is knuckle walking on four limbs. The arms are longer thanthe legs. There is much less size difference between the males and thefemales. They eat mainly fruit and leaves or they will eat smallmammals such as colobus monkeys. They live for 30–40 years.They are one of the most intelligent animals and make tools.

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Jane Goodall is a famous scientist who has studied chimpanzees formany years. She has written about the strong social orderamongst chimps.

Optional activity

If you are interested in chimpanzees here are some interesting webpagesabout the work of Jane Goodall.

http://www.lmpc.edu/science

Chimpanzees are highly social and live in groups of 20–100 individuals.They use tools to gather food. They shape sticks to extract termites fromtheir holes and rocks and clubs for breaking nuts.

Summary of hominoid features

• flat face

• more opposability in the digits

• nails on every digit

• good colour, binocular vision

• menstrual cycle

• single uterus

• relative slow growth

• no tail

• shoulders adapted for brachiation

• larger body size.

36 The human story

Identify the group of each primate in the photographs following.

Ring–tailed lemur.(Photograph: © David Haring Duke UniversityPrimate Centre)

Gibbon.(Photograph: Jane West)

Macaque.(Photograph: Jane West)

Chimpanzee.(Photograph: © (Tim Knight Primate Gallery)<http://www.selu.com/bio/PrimateGallery>

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Spider monkey.(Photograph: Jane West)

Patas monkey.(Photograph: © (Tim Knight Wildlife Gallery)<http://www.selu.com/bio/wildlife>

Check your answers.

Do Exercise 1.4 now.

Hominins

Humans are the only living hominins alive today but we will see later inthis module that that was not always the case.

They are large primates with an upright stance and bipedal locomotion.They have a locking knee joint and the big toe is not opposable.The limbs are equal in length. The trunk is relatively slender and humansare slightly built compared to other apes.

The ribs of humans are broad and barrel shaped. The pelvis of humans isshorter and they are not pot-bellied like apes. Human legs are longerthan apes with the thighbone angling towards the knee placing the feetcloser together and therefore directly under the centre of gravity of thebody. Human feet are flat compared to the curved feet of apes.Human hands are flatter and broader and the fingertips flatter withsensitive nerve endings in the tips. The human brain size of 1350 cc islarger than the apes at 400 cc.

When this is compared to body size the relative size of the human brainis much greater. The dental arch in gorillas is U-shaped while in humansit is a parabolic arch. Ape teeth have thin enamel while humans havethick tooth enamel. No bony ridges over the eyes. Live exclusively onthe ground. You will be looking at the classification of humans in thenext section.

38 The human story

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Human classification

Humans share characteristics with many groups of animals.At each level of classification humans share characteristics with the othermembers of the group.

Humans have an upright stance and are bipedal. They use durable toolsand are capable of speech and abstract thought. They have a prolongedperiod of parenting. They have reduced hair on their bodies with coarsehair found on the head, armpits and pubic area. There is an S-shapedspine and a broad pelvis. The legs are longer than the arms.Human feet have an arch to facilitate walking on two feet.

Ape and human skeleton. Notice the difference in the pelvis, the position of theskull on the spine and the relative sizes of the arms and the legs.

40 The human story

Humans have an opposable thumb set at an angle that allows for both apower grip and precision grip.

The first photograph shows the precision grip while the second illustrates thepower grip of the human hand.(Photograph: Jane West)

Looking at the bones of the leg, the human femur slopes inwards and theknees lock into position.

Human leg and an ape leg. Notice the angle of the bone and the differences inthe shape of the pelvis.

The foramen magnum is located directly underneath the skull.This keeps the head erect and facing forward when standing on two feet.

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Gorilla and human skull as viewed from the underside. The dark shaded areais the foramen magnum.

There is a large brain enclosed in the protective skull. This is the resultof a large cerebral cortex. The brain is greatly folded giving it a largesurface area. The eyebrow ridge is small and there is a prominent nose.

Compare the brain size of the gorilla and the human. Both have a large brainsize to body size when compared to other mammals but in the human the brainto body size is larger.

The jaw of humans is parabolic compared to the rectangular shapeof apes.

42 The human story

The jaw of a human and an ape. He human has a parabolic shaped jaw whilethe ape has a rectangular jaw.

You have to know the characteristics of humans that classify them into thegroups listed below. As a pre-test write down features that humans sharewith each group. Later in this part you will revisit this classification schemeto see if you can improve on your features.

animals ___________________________________________________

chordates__________________________________________________

mammals _________________________________________________

primates __________________________________________________

apes _____________________________________________________

hominids _________________________________________________

Homo ____________________________________________________

sapiens ___________________________________________________

Word meanings. You will use the words listed below in your classificationof humans. Look up the meanings of any of these words that you are notfamiliar with. (Hint: There is a glossary at the start of the module)

heterotrophic, eucaryotic, multicellular, mobile, notochord, pharyngeal slits,dorsal, diaphragm, opposable, foramen magnum

Write definitions for each of these words in Exercise 1.5.

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Human characteristics

Below is a summary of the characteristics that humans share with eachgroup. In this activity you will be gathering information to show howhumans are classified into groups.

Humans as an animal

Animals are heterotrophic, eucaryotic with no cell walls, multicellularand mobile.

List some examples of animals.

_________________________________________________________

_________________________________________________________

_________________________________________________________

Check your answers.

Humans as a chordate

Chordates are animals with a notochord (rod of tissue found on thedorsal side of embryo) and a dorsal hollow nerve cord. They havepharyngeal slits at least in the embryonic stage.

Give some examples of chordates.

_________________________________________________________

_________________________________________________________

_________________________________________________________

Check your answers.

Humans as a mammal

The unique features of mammals are fur or hair and milk-producingglands. Other features are three separate bones in the middle ear; a lowerjaw composed of only one bone; a four-chambered heart; a diaphragmseparating the chest and the abdomen; and are homiothermic.

List examples of mammals.

_________________________________________________________

_________________________________________________________

_________________________________________________________

Check your answers.

44 The human story

Humans as a primate

Primate features include: fingernails and toenails; an opposable thumb;stereoscopic/ binocular vision with forward facing eyes; a relatively largebrain with a well developed cerebral cortex; ridged finger pads; aflattened face with a reduced sense of smell and forward facing eyes; twonipples with a reduced number of young at each birth; a long period ofcare for the young; and elongated limbs and digits.

List some examples of primates.

_________________________________________________________

_________________________________________________________

Check your answers.

Humans as hominids

The features of hominids are: the absence of a tail; shoulder blades at theback; Y-shaped pattern on the surface of the molar; an agile forearm; anda flat nose with a reduced sense of smell.

List some examples of hominids

_________________________________________________________

_________________________________________________________

_________________________________________________________

Check your answers.

Humans as hominins

The features of a hominin are: an upright gait; the arms are shorter thanlegs; a parabolic jaw with even teeth; an arched foot; a large thumb witha greater degree of opposability; a narrower pelvis than other primates;legs close together.

Examples of hominids are Australopithecus afarensis,Australopithecu robustus.

Humans as Homo

The features of Homo are: bipedal; unspecialised dentition; knee caplocks leg when straightened.

Examples of Homo are Homo habilis, Homo erectus.

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Humans as Homo sapiens

Homo sapiens have: a large brain (850 cc–1400 cc) especially thecerebral cortex with greater development of the frontal lobes; thepresence of a chin; an upright stance; a foramen magnum at the base ofthe skull; S-shaped spine; a broad and bowl-shaped pelvis to support theorgans; capability of speech and abstract thought.

Do Exercise 1.6 now.

Dispute in classification

The traditional versus the genetic techniques of classification has causedmuch dispute. As new technologies emerge they either support thecurrent taxonomy or lead to changes to make the groups fit the evidence.In the next part of this unit you will be looking at new techniques that areused for classification and for working out the evolutionary relatednessof our species.

These techniques include

• karyotype analysis

• DNA-DNA hybridisation

• mitochondrial DNA

• DNA sequencing

• amino acid comparison

• haemoglobin analysis.

Historically primates were classified by their morphological similarities.As new techniques are developed new relationships are worked out.Gorillas, chimpanzees and humans are closely related.Anatomically gorillas and chimpanzee look like they are more closelyrelated to each other than they are related to humans. This was thetraditional classification.

Morris Goodman in the late 1970s used the strength of an antibodyresponse to the protein albumin. If the two species were the same thestrength of the response to the protein should be the same. Close geneticrelationship would be reflected by similar protein structure.This challenged the traditional classification.

Traditionally the apes were placed in the Pongidae family and humanswere placed in the Hominidae. The results from the molecular datashowed that the African apes should be in the family Hominidae and

46 The human story

orangutans should be in the family Pongidae. Goodman’s research onthe comparison of serum protein was the start of the science ofmolecular anthropology.

Another step in technology was DNA–DNA hybridisation.Traditional anatomical evidence placed chimpanzees and gorillas closertogether than either was to humans. DNA–DNA hybridisation studiesshowed that chimpanzees and humans were each other’s closetrelationship with gorillas separate. This relationship has been supportedby DNA mapping.

As new technologies become available the classification system isreviewed. Within the primates there have been changes to thegroupings of apes and humans which have occurred because of advancesin technology.

Example 1: The classification of the tarsier

Traditionally tarsiers have been classified as prosimians and that is thesystem used in this module. Tarsiers are a mysterious species, as theydon’t fit in with either of the main primate groups. Physically theyresemble the prosimians but molecular evidence has put them closer tohumans and the anthropoids. This has led to differentclassification systems.

Alternative Classifications of the Order Primates

Classification of tarsiers–some scientists stress that tarsiers have manycharacteristics in common with the Anthropoidea. Some of thesescientists divide the order into two suborders:

• Strepsirhini (lemurs, lorises, and galagos)

• Haplorhini (tarsiers, monkeys, apes, and humans)

Others divide the order into three suborders:

• Prosimii (lemurs, lorises, and galagos)

• Tarsioidea (tarsiers)

• Anthropoidea (monkeys, apes, and humans)

Tarsiers appear to be intermediate between the prosimians and theanthropoids this makes their classification difficult.

Features shared with prosimians

Tarsiers, like prosimians, have a small size, nocturnal habit, non–fusedlower jaw, two claws on each foot, enormous eyes and small brains

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Features shared with anthropoids

Tarsiers, like anthropoids, have a dry snout. eyes with a small blind spotand upright lower incisors.

Changing technology has changed the classification of the tarsier.

Example 2: The classification of the Hominoidea

There are different proposals for the classification of the Hominoidea(apes and humans). Traditionally anatomical features were the only onesconsidered. The molecular evidence has led to different interpretations.Below are three different classification schemes.

1 Superfamily Hominoidea

Family Hylobatidae (gibbons and siamang)

Family Pongidae (orangutan)

Family Gorillidae (gorillas)

Family Panidae (bonobo and chimpanzee)

Family Hominidae (humans)




Family Panidae (bonobo, chimpanzee, gorilla)

Family Hominidae (humans)




Family Hominidae (bonobo, chimpanzee, gorilla, humans)

There is some more information on this in Part 2 of this module.

48 The human story

Hominid vs. hominin debate

When you begin gathering information for your next research assignmentyou will come across the terms hominid and hominin. In the olderclassification system hominid referred to the group of bipedal apesincluding present day humans. This grouping has now become hominins.

Recent research using molecular evidence places the African apes closerto the lineage of humans than the anatomical evidence suggested.Therefore in the new system hominids include both humans and theAfrican apes (chimpanzees and gorillas).

Hominins are all hominids but the distinction is that the hominins are thebipedal apes that include modern humans and their recent ancestors.Be aware as you research that the use of these terms will be differentfrom different authors. Check the date of the material you are using asthis will give you an idea of whether the material is up–to–date.

The example above of changes in classification systems based onemerging technology illustrates the arbitrary nature of classification.Classification comes about because of our need to sort things intomanageable groupings. Unfortunately the natural world is not as cut anddried as we would like it to be. Therefore classification reflects changesin ideas and emerging technology.

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Similarities anddifferences in primates

Your task in the last section of this part is to look at the similarities anddifferences in primates. Ideally this task should be done as a zoo visit.If you do get an opportunity to go to the zoo then some of the workloadcan be shared or you could compare your answers with otherbiology students.

Observing primates

If you are able to visit a zoo then complete the tasks below during your visit.If you are unable to visit a zoo then there are two ways you can completethis exercise. If you have access to the Internet then visit the virtual primateexcursion on the LMP website.

http://www.lmpc.edu.au/science

If you do not have access to the Internet the photographs are reproducedfollowing and you should be able to complete the exercise using these.

During this activity you will be asked to observe primates. Observation is askill that needs to be developed. You have to observe carefully. If youhaven’t observed something don’t record it as an observation. Don’t thinkall monkeys have a tail or all monkeys have an opposable thumb becausethere are always exceptions to rules. Be very careful with your observations.If you can’t see the shape of a primate’s hand then don’t comment on theopposability of the digits.

You will be looking at the following groups of primates

• prosimians

• monkeys

• apes

• humans.

50 The human story

You have already studied the main features of each of these groups sobefore you start this practical activity summarise the features of eachgroup and give some examples in the space provided.

Prosimians

_________________________________________________________

_________________________________________________________

_________________________________________________________

Monkeys (New and Old world)

_________________________________________________________

_________________________________________________________

_________________________________________________________

Apes

_________________________________________________________

_________________________________________________________

_________________________________________________________

Humans

_________________________________________________________

_________________________________________________________

_________________________________________________________

Now look at the following primate examples.For each example comment on:

• the shape of the face (elongated/ flat)

• position of the eyes (forward facing/ side facing)

• description of fingers, (claws, nails, opposability thumb/toe)

• body stance (body erect/ body bent)

• tail (present/absent/prehensile)

• walk on four or two limbs

• hindlimbs shorter/hindlimbs longer

• nostrils facing down/side facing

• body covering.

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Prosimians

Ring–tailed lemur

Ring tailed lemur.(Photograph: © David Haring Duke University Primate Centre).

The shape of the face (elongated /flat) __________________________

Position of the eyes (forward facing/ side facing) _________________

Description of fingers, (claws, nails, opposability thumb/toe) ________

Body stance (body erect/ body bent) ___________________________

Tail (present/absent/prehensile) _______________________________

Walk on four or two limbs ___________________________________

Hindlimbs shorter/hindlimbs longer ____________________________

Nostrils facing down/side facing ______________________________

Body covering_____________________________________________

52 The human story

Slow loris

Slow loris.(Photograph: ©Tim Knight Primate Gallery)<http://www.selu.com/bio/PrimateGallery.>

The shape of the face (elongated/ flat) ___________________________

Position of the eyes (forward facing/ side facing) __________________

Description of fingers, (claws, nails, opposability thumb/toe)_________

Body stance (body erect/ body bent) ____________________________

Tail (present/absent/prehensile) ________________________________

Walk on four or two limbs ____________________________________

Hindlimbs shorter/hindlimbs longer_____________________________

Nostrils facing down/side facing _______________________________

Body covering _____________________________________________

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New world monkeys

Capuchin monkey

Capuchin.(Photograph ©Tim Knight Wildlife Website)< http://www.selu.com/bio/wildlife.)>

Black–capped capuchin.(Photo ©Tim Knight Primate Gallery)< http://www.selu.com/bio/PrimateGallery >

The shape of the face (elongated/ flat) __________________________


54 The human story







Body covering _____________________________________________

Spider monkey

Spider monkey.(Photograph: Jane West)









Body covering _____________________________________________

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Lion-headed tamarin

Golden Lion Tamarin.(Photograph ©Tim Knight Primate Gallery)<http://www.selu.com/bio/PrimateGallery>









Body covering_____________________________________________

56 The human story

Marmosets

Gold marmoset.(Photograph ©Tim Knight Primate Gallery)<http://www.selu.com/bio/PrimateGallery >









Body covering _____________________________________________

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Old world monkeys

De Brazza monkey

De Brazza monkey.(Photograph ©Tim Knight Primate Gallery)<http://www.selu.com/bio/PrimateGallery >









Body covering_____________________________________________

58 The human story

Baboon

Hyadrryas baboon.(Photograph ©Tim Knight Wildlife Website)< http://www.selu.com/bio/wildlife >








Nostrils facing down/ side facing_______________________________

Body covering _____________________________________________

Baboon troop.(Photograph: B. Norris)

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Apes

Gibbon

Gibbon.(Photograph ©Tim Knight Wildlife Website http://www.selu.com/bio/wildlife ).

Silvery gibbon.(Photograph ©Tim Knight Primate Galleryhttp://www.selu.com/bio/PrimateGallery )

60 The human story









Body covering _____________________________________________

Orangutan

Orangutan.(Photograph ©Tim Knight Wildlife Website http://www.selu.com/bio/wildlife ).







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Body covering_____________________________________________

Hominids

Chimpanzee

Chimpanzee.(Photograph ©Tim Knight Wildlife Website http://www.selu.com/bio/wildlife ).

62 The human story









Body covering _____________________________________________

Gorilla

Silverback gorilla knuckle walking.(Photograph © Tim Knight Gorillas Online http://www.selu.com/bio/gorilla )

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Gorilla face.(Photograph ©Tim Knight Gorilla's Online http://ww.selu.com/bio/gorilla ).









Body covering_____________________________________________

64 The human story

Hominins

Human









Body covering _____________________________________________

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Summarise your observations in the table below.

Primate Faceshape

Eye position Fingers Tail

Ring-tailed lemur

Slow loris

Capuchin monkey

Spider monkey

66 The human story

Lion-headed tamarin

Marmosets

De Brazzi monkey

Baboon

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Gibbon

Orangutan

Chimpanzee

Gorilla

68 The human story

Human

From the table above write a report on the similarities and the differencesfound amongst the primates. You may like to use the scaffold providedbelow to plan your report and then write your finished report in Exercise 1.8.

Report title

Write a name for the experiment

Aim:

What did you set out to achieve?

Method:

What you actually did.

Results:

What did you find out?

Conclusion:

Did you achieve your aim?

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HSC style questions

Try these HSC style questions and then check your answers.

a) List four characteristics that are used to classify humans as primates.

_____________________________________________________

_____________________________________________________

_____________________________________________________

b) List two characteristics which humans share with

i) mammals

_________________________________________________

_________________________________________________

ii) primates

_________________________________________________

_________________________________________________

ii) other humans

_________________________________________________

_________________________________________________

c) Name two features of humans that allow them to be classified asprimates.

_____________________________________________________

_____________________________________________________

Check your answers.

There are some more HSC style questions for you to do in Exercise 1.9.

You have finished looking at the classification of the primates. In the nextpart of this module you will look at the biological evidence forclassification.

70 The human story

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Summary

Levels of classification

Kingdom Phylum Class Order Family Genus Species

Classification of humans

Classification level Human Feature at this level

Kingdom Animalia heterotrophic, no cell wall

Phylum Chordata have a notochord or dorsal nervetube, pharyngeal slits

Subphylum Vertebrata backbone

Class Mammalia hair, mammary glands, specialisedteeth, four chambered heart,

Order Primates opposable thumb, nails, binocularvision, forward directed eyes, 2nipples

Family Hominidae absence of tail, reduced sense ofsmell, agile forearm, nails on everydigit

Genus Homo bipedal gait, erect posture, S-shapedspine, foramen magnum facing down

species sapiens large brain, speech, complex socialsystem

72 The human story

A definition of a species

A group of actually or potentially interbreeding natural populationsthat is reproductively isolated from other groups.

Primates have similarities including:

• hand/foot structure

• skull shape and function

• relative brain size

• arrangement of vertebral column

• vision

• reproductive features

• parenting and group bonding

• retention of the clavicle(collarbone)

• a mobile shoulder joint allowing free movement

• usually two nipples.

Primate classification is difficult and there are different ideas of therelationships between primates based on the traditional classificationbased on anatomy and the newer molecular evidence.

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Suggested answers

Classification

The dog and the cat are more closely related because they belong to thesame kingdom, phylum, class and order. The kangaroo is in a differentorder so it is not as closely related.

Summary of prosimian features

Name ofprosimian

Grasping handsand feet

Flattened nails Forward facingeyes

aye-aye ✗ ✗ ✗

sifaka ✗ ✗ ✗

potto ✗ ✗

Anthropoids

prehensile tail–ability to grasp or hold, usually a prehensile tail is used asa fifth limb

arboreal–lives in tree

opposable thumb–the ability of the thumb to be brought into contact withany of the fingers

omnivores–eat a diet consisting of both plant and animal material

rhinarium–wet snout of prosimian monkeys

nocturnal–animals that move around and seek their food mainly at night

74 The human story

binocular vision–involves the use of two eyes; the field of overlap resultsin three dimensional vision

callosities–the large pad on the rump of monkeys that is used whensitting, often coloured

sexually dimorphic–male and females of a species that have differencesin physical appearances based on sex

bipedal–walking on two feet

quadrapedal–walking on four feet

Summary of hominoid features

Name Group

ring-tailed lemur prosimian

gibbon lesser ape

macaque old world monkey

chimpanzee hominid

spider monkey new world monkey

Patas monkey old world monkey

Humans as an animal

There are lots of examples eg. cats, dogs. kangaroos, jellyfish, ants,frogs, magpies.

Humans as a chordate

Includes all reptiles, birds, fish, amphibians and mammals.

Humans as a mammal

Kangaroo, horse, cat, dog.

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Humans as a primate

Lemurs, tarsier, gorilla.

Humans as hominids

Chimpanzee, gorillas.

HSC style questionsa) Opposable digits on hands, large brain size, binocular vision,

reduced sense of smell, unspecialised body, forward facing eyes.

b) i) Mammals and humans have a body covering of hair or fur,suckle their young

ii) Primates and humans have forward facing eyes, ears on eitherside of the head, opposable digits.

iii) Humans have a large brain, speech and extensive tool use.

c) Fingernails, binocular vision, large brain, opposable thumb.

76 The human story

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Exercises – Part 1

Exercises 1.1 to 1.8 Name: _________________________________

Exercise 1.1a) List two reasons why scientists classify organisms.

_____________________________________________________

_____________________________________________________

b) Outline the general classification hierarchy from phylum to species.

_____________________________________________________

_____________________________________________________

_____________________________________________________

Exercise 1.2a) Define the term species and outline the criteria used to identify a

species.

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

b) What is a hybrid? Give an example.

_____________________________________________________

_____________________________________________________

_____________________________________________________

78 The human story

Exercise 1.3

The primates are an unspecialised group of mammals. Describe thecharacteristics of the primate group.

_________________________________________________________

_________________________________________________________

_________________________________________________________

Exercise 1.4

For each of the groups below describe the features of the group and givean example.

a) Prosimians

______________________________________________________

______________________________________________________

______________________________________________________

______________________________________________________

______________________________________________________

b) New World monkeys

______________________________________________________

______________________________________________________

______________________________________________________

______________________________________________________

______________________________________________________

______________________________________________________

c) Old World monkeys

______________________________________________________

______________________________________________________

______________________________________________________

______________________________________________________

______________________________________________________

______________________________________________________

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d) Hominoid

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

e) Hominid

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

f) Hominin

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

Exercise 1.5

Give meanings for each of the following terms.

heterotrophic ______________________________________________

_________________________________________________________

eucaryotic ________________________________________________

_________________________________________________________

multicellular ______________________________________________

_________________________________________________________

mobile ___________________________________________________

_________________________________________________________

80 The human story

notochord _________________________________________________

_________________________________________________________

pharyngeal slits_____________________________________________

_________________________________________________________

dorsal ____________________________________________________

_________________________________________________________

diaphragm_________________________________________________

_________________________________________________________

opposable _________________________________________________

_________________________________________________________

foramen magnum ___________________________________________

_________________________________________________________

Exercise 1.6

In the space below write out the features that identify humans at each ofthe following levels.

Animal ___________________________________________________

_________________________________________________________

Chordate __________________________________________________

_________________________________________________________

Mammal __________________________________________________

_________________________________________________________

Primate ___________________________________________________

_________________________________________________________

Hominid __________________________________________________

_________________________________________________________

Hominin __________________________________________________

_________________________________________________________

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Homo____________________________________________________

_________________________________________________________

Homo sapiens _____________________________________________

_________________________________________________________

Exercise 1.7

Identify technological advances that have changed scientists’ opinionsabout the classification of primates.

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

82 The human story

Exercise 1.8

Report on primates.

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

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_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

Exercise 1.9

HSC style questions

a) List two features that place humans into each of thefollowing groups

i family Hominidae

_________________________________________________

_________________________________________________

ii order Primates

_________________________________________________

_________________________________________________

iii class Mammalia

_________________________________________________

_________________________________________________

3 marks

b) A lemur is an example of a prosimian and a baboon is an example ofan anthropoid. State two ways that Prosimians differ fromAnthropoids.

_____________________________________________________

_____________________________________________________

2 marks

84 The human story

c) The primate ancestors of early man were unspecialised.Give two primate characteristics and state why these features wereimportant for the later evolution of humans.

______________________________________________________

______________________________________________________

______________________________________________________

3 marks

d) State two features that separate Prosimians and Anthropoids.

______________________________________________________

______________________________________________________

2 marks

e) Define the following terms:

primate _______________________________________________

hominoid ______________________________________________

anthropoid _____________________________________________

3 marks

f) Humans are classified as:

Phylum Chordata________________________________________

Class Mammalia ________________________________________

Order Primates__________________________________________

Family Hominidae_______________________________________

Genus Homo ___________________________________________

Species sapiens _________________________________________

For each of the levels of classification state one characteristic that isused to include humans.

6 marks

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