Grade 11 Zoology Note

Origin and Evolution of Life

 

Origin of life: It is generally agreed that all life today evolved by common descent from a single primitive lifeform. We do not know how this early form came about, but scientists think it was a natural process which took place perhaps 3,900 million years ago.

Origin of earth and its atmosphere:Earth is believed to have formed about 5 billion years ago. In the first 500 million years a dense atmosphere emerged from the vapor and gases that were expelled during degassing of the planet's interior. These gases may have consisted of hydrogen (H2), water vapor, methane (CH4) , and carbon oxides. Prior to 3.5 billion years ago the atmosphere probably consisted of carbon dioxide (CO2), carbon monoxide (CO), water (H2O), nitrogen (N2), and hydrogen.The hydrosphere was formed 4 billion years ago from the condensation of water vapor, resulting in oceans of water in which sedimentation occurred.

Evolution is a branch of science deals with the unfolding of new and complex species from simple species.

There are different plants and the animals which evolve in different ways in different habit, habitat or adaption. In general evolution is a dynamic process in which gradual change of body morphology takes place, after long period of time convert into more and more complex animal.

Scientific hypothesis-

Chemical evolution of life:

Chemical evolution describes chemical changes on the primitive Earth that gave rise to the first forms of life. The first living things on Earth were prokaryotes with a type of cell similar to present-day bacteria. Prokaryote fossils have been found in 3.4-million-year-old rock in the southern part of Africa, and in even older rocksin Australia, including some that appear to be photosynthetic. All forms of life are theorized to have evolved from the original prokaryotes, probably 3.5-4.0 billion years ago.

a) Formation of Simple Compounds: The first stage of chemical evolution, molecules in the primitive environment formed simple organic substances, such as amino acids, methane, ammonia, water etc.

b) Formation of Organic Compounds: In the second stage of chemical evolution, the simple organic molecules (such as amino acids) that formed and accumulated joined together into larger structures (such as proteins). The units linked to each other by the process of dehydration synthesis to form polymers.

c) Formation of complex organic compound: simple organic molecules combined to form complex organic compounds like polysaccharides, fats, protein, nucleotides, nucleosides, nuclic acid etc.


Biological evolution: 
a) Formation of Protobionts (Coacervates): The next step in chemical evolution suggests that polymers interacted with each other and organized into aggregates, known as protobionts. Protobionts are not capable of reproducing, but had other properties of living things.

b) Formation of primitive life: In this stage protobionts developed the ability to reproduce and pass genetic information from one generation to the next.

 

 

Evolution is defined as slow and gradual process in which simple animal slowly changes into complex animal in relation to environment.Evolution can also define as descent with modification. Based upon the origin, evolution categories into two types;

a) Inorganic evolution: Evolution of inorganic structure such as earth itself, valleys, plateaus, hills, Himalayas, etc.

b) Organic evolution: Evolution of the animals from the simplest organic compounds such as amino acid, glucose, fructose, fatty acid, nucleotides, etc.

On the basis of the morphological characters, organic evolution further sub-divide into following;

a) Progressive evolution: Gradual change in the animal character from the simple to more and more complex. For e.g. origin of man from monkey like creature.

b) Retrogressive evolution: Development of the adults in primitive forms. For e.g.; Herdmania or Ascidian

c) Parallel evolution: Evolution of two similar different animals goes side by side in their general characters during evolution. For e.g. old worldmonkey and new world monkey.

e) Convergent evolution: Animals having similar functional characters but belongs to different category of animals. For eg; wings of bat, bird, butterfly, etc.

f) Divergent evolution: Evolution from the common ancestor but looks different in the morphological character. For eg: Hominoidea group like gorilla, Orangutan, Chimpanzee and Man.

 

Theories of Evolution:

For the explanation of origin of life, there are different theories. Some of them are follows;

a) Theory of spontaneous generation.

b) Theory of special creation.

c) Theory of cosmozoan.

d) Theory of biogenesis.

e) Theory of steady state.

f) Theory of catastrophism.

g) Theory of organic evolution, etc.

 

Theory of spontaneous generation: This theory said that origin of life takes place suddenly and instantly from non- living things. For example;

1. Crocodile evolved from the muddy water of river Nile.

2. Desert scorpion evolved from camel dung or excreta.

3. Flies, insect evolved from the decomposite materials.

4. Moist clothes with grains after 20-21 days found young of rats.

In that period, Pasture experimentally proved that origin of life takes place from pre- existing life. After the view of Pasteur, this theory was totally discarded.

b) Theory of special creation: This theory said that all the living beings existing these days were also present in the beginning simply remain in unknown.

This view could not explain the development of new animals or plants as well as growth of population. Therefore, later the religious people published theory of special creation which said that all the living beings were created by god and goddess.

c) Theory of cosmozoan: This theory said that first primitive life on the earth surface was come from outer surface or space and was called Panspermia.

Due to lack of evidences this theory was also discarded.

d) Theory of biogenesis: This theory related with the origin of life from free existing life. The 

theory was forwarded by Francesco Reddi. Later theory was supported by the scientist Spallanzeni and Pasteur.

1. Reddi’s experiment: He collected dead snakes, meat and put into the several jar with or without coverings. In the covered jar, he didn’t find any extra life but found in the jars having no coverings. Thus he concluded that orifgin of life takes place from pre- existing life not from non-living things.

2. Spallanzeni’s experiment: He collected both from the continous boil meat and was kept in several jars with or without coverings. He also found extra life development only in the jars without coverings. Thus concludes in similar manner.

3. Pasteur’s experiment: Pasteur experimented simple experiment as shown in the figure. He took swan necked bottle in which kept hay particles and added tap water. The solution was boiled for hours and hours. Then, let free for few days. After few days, he found certain extra life in the neck of the bottle having condensed liquid. But no sign of extra life in the main solution. After that he broke the neck of the bottle and again let free for few days. Later found extra life in the main solution which no doubt came from atmospheric air. Hence origin of life only takes place from pre- existing life but never from non-living things.

 

Theory of Organic evolution:

This is the latest and most scientific theory which said that in the beginning origin of life took place from simplest organic compounds but later from pre- existing life.

It is believed that our planet earth existed since 4.5 billion years back. In the beginning, the surface of the earth was too hot. Temperature believed between 3000-4000⁰C and was surrounded by primitive atmosphere. As the time passed gradually temperature decreases on the surface. Various reactions took place in the primitive atmospheric gases in the presence of high voltage energy. As a result first primitive living solution was developed at the sea bed. It was called coacervate solution having replicating characters. After the solution has also called Darwin’s little pond or earth primodeal soup or both.

The coacervate solution shows the composition of organic compound like amino acid, pentose sugar, fatty acid, nucleotides etc. With the change of climatic condition from the coacervate solution evolved first primitive life called cynobacteria or blue green algae. Since 3.2 billion years back. Later evolved prokaryotic organisms like bacteria and evolved eukaryotic organism like protozoans. In these manner slowly evolved more and more complex organisms such as poriferans, coelenterates, platyhelmenths and so on.

 

Oparin- Holdane theory:

Alexander Oparin in 1923 and JBS Haldane in 1928, both the scientist supported theory of organism and published theory called Oparin Holdane theory.

According to this theory said that in the beginning life was originated from the simplest organic compounds. In the early origin of the earth was blanketed by primitive atmosphere or reducing atmosphere which constituted various gases like CO₂ , CO, SO₂, SO₃, N₂, NO₂, N₂O₅, H₂S, CH₄, H₂O, etc. Among these gases, most of the gases reacted with each other in presence of high energy which may be energy from lightening, energy from solar energy or sun, energy from radioactive element, energy from volcanic eruptions.

The reactions of gases resulted out of the permission of primitive living replicating solution coacervate. This solution evolved first life cyanobacteria or blue green algae.

Conclusion: Origin of life took place from simplest organic compound in the beginning but not these days.

 

Miller Urey experiment:

Miller and Urey in 1953 experimentally supported the theory given by Oparin Haldane regarding origin of life from simplest organic compounds.

They set up the experiment as shown in the figure, in the gas bulb four gases were taken such as water vapour, H₂,CH₄ and ammonia and were reacted at very high voltage. After the reaction, reacted gases, passed through cooling jacket for condensation. The condensed liquid was collected in the resultant bottle and analysed in the lab.

Resultant solution was found the mixture of amino acid and pentose sugar which was also the basic component of coacervate solution.

There is no doubt that in the beginning life originated from the simplest organic compound but these days. Only, originate from the pre-existing.

Evidences for the support of organic evolution:

1.Evidence from comparative anatomical character or morphological characters.

a)Homologus organs

b) Analogous organs

c)Vestigeal organs

d)Connective link

2.Evidence from embryological character.

3.Evidence from paleontological or fossil research character.

4.Evidence from physiology or bio-chemistry

6.Evidence from Genetics.

 

a)Homologus organs: They are those organs having similar origin and anatomy but differ in morphology and functions.

With the help of homologous organs of the animals can trace out the common ancestor. For eg; forelimb bones of the animals are humerous, Radio-ulna, carpels, metacarpels and phallenges.

In the above animals origin of the bones are similar anatomically arrangement are similar but only differs in their morphology and functions because of different adaption. Hence having similar characters in the origin showed that all the vertebrates might have the common origin in the beginning.

b)Analogous organs: They are those organs which look different in origin, anatomy and morphology but have similar functions. For eg;

Wings of bird – forelimb modification

Wings of butterfly – thoracic appendage.

c)Vestigeal organs: They are those organs which were functional in the past but these days became totally non- functional.

With the help of vestigial organs also can find out the possible ancestor. It is believed that in human body, there are more than 200 vestigeal organs organs which showed the origin of man from different characters. Some of the vestigial organs are as follows;

Name of the organ

Location of the organ

function

Possible origin

1.Pinnae muscles

Around the pinnae

Help in the movement of pinnae for the collection of sound.

Movable pinnae ancestor

2.Vermiform appendex or short cylindrical

In between calcium and colon i.e. in the large intestine

Secrete enzyme cellulose for the digestion of cellulose or pectin or chloroplast

herbivorous

3.Mictitating membrane or 3rd eye lid or plica-semilunaris

Outside the eye ball

Protection for cornea

Functional mictitating ancestor

4.Post-anal tail

Very close to anus upper

For body balancing

Tailed ancestor

 

d)Connective link(connecting link): Connecting link or missing link is a character shown by the animals belonging to two or more than two different groups. For e.g. extinct Jurrasic reptile or bird Archeopteryx is the best example of it. It shows the character of two different groups.

1.Avian character:

- Body covers by feathers.

- Four limbs modified into wings.

- Presence of tail feathers

- Bones pneumatic

- Flying habit

2.Reptilian character:

- Hind limbs scaled

- Beak with teeth

- Tail short

- On the land shows crawling locomotion.

Therefore birds are also called glorified reptiles.

2.Evidence from embryological character: Embryology deals with the development of embryos, every vertebrate embryo shows following common character.

a. Presence of single median eye spot for sensation.

b. Presence of simple two chamber heart.

c. Presence of pharyngeal gill slits for respiration.

d.Presence of post and tail.

Presence of similar above character in all the vertebrate embryos means they might have the common ancestor. This character was present in prehistoric embryos so can be called as Phylogeny characters and also found in present embryos, can be called as ontogeny characters. Therefore, it can be said that ontogeny follows phylogeny.

According to the scientist Huxley, ontogeny follows phylogeny said to be recapitulation characters produced theory of recapitulation.

3.Evidence from paleontological or fossil research character:

Paleontogy deals with the study of fossils belonging to extinct animals. The study of fossil provides most convening and direct evidence of evolution. They help to trace the facts correlated with their origin and evolution, relationship, increasing complexity etc. The fossil evidences reveal a gradual development of organisms with time. Animals are better preserved as fossils as compared to plants.

Types of fossil:

Unaltered: In, these types, whole bodies of extinct organisms have been formed frozen in ice at the poles. This type of fossil found about 25000 years ago.

Petrified: This is rare type of the fossil. In this type the organic parts of body gets partly or completely replaced by mineral deposits, the replacement of organic parts by minerals deposits is called petrifaction.

Impression: These are formed by the organisms or the parts of the organism come in contact with soft clay.

Compression: These fossils are formed as a result of burial of organisms. It is useful in the study of the external morphology.

Cast or moulds: These are formed when an organism get submerged in water containing lime. Moulds exhibit the same external configurations of the organisms.

Importance of Paleontology:

1. It helps to reconstruct or build the chain of evolution.

2. It helps to understand the way of evolution.

3. It helps to study about the habitat and behavior of the extinct organism.

4. It helps to understand the structure of extinct animal.

 

Evolution of modern horse

On the basis of fossils records, it is conferred that the true ancestor of modern horse was Eiohippus which where lived 52 million years back. It was the size of the fox and possessed 4 limbs digits. From eiohippus modified into miohippus and mericyppus since 27 million year back. The body size slightly increases with 3 digits in the limbs. Phiohippus came into existence with almost the size of the donkey with two functional digits in the limbs with slightly extended Muzzele since 13 million year.

The modern horse equals gained full body shape since 2 million year back which is still continuing. Due to continuous running habit limbs of the modern horse.

Hence in compare to the other evidence paleontological evidence is the best due to recovery of fossils of the extinct animals.

 

Evidence from physiology or bio-chemistry:

The bio-chemical natures of the cells of the animal are very similar to each other. E.g. enzyme tripase which digest protein in the amino acid is also present in the earthworm, cockroach, and frog and even in man. Similarly amylase and lipase are also present, help in the digestion of carbohydrate and fat. Presence of enzyme in lower invertebrates and higher invertebrates. Lower and higher invertebrate’s means probably belongs to common ancestor. The analysis of single animal cells shows similar characters in the cells of the all animals.

Blood sera or serum constitute plasma and corpuscles. RBC of the all mammals looks more or less similar showing similar origin.

About 5ml of blood of man and monkey, horse and donkey, cow and buffalo etc mixed together in the test tube shows less agglutination. If the blood of man and monkey mixed together with the blood of horse and donkey immediately agglutination takes place that is man and monkey must have close ancestor.

The haematic crystal of man and monkey looks very similar but differs with the horse and donkey or cow which also shows the similar common ancestor.

Evidence from Genetics

Genetics deals with the study of genes which carry hereditary characters from generation to generation.

On the basis of structure of genes of man and gorilla looks very much similar therefore must have the common ancestor.

 

Theory of Lamarck or Lamarckism or Theory of inheritance of acquired characters:

Jean Baptist De Lamarck (1744-1829) was a famous Botanist in that period has written many books and articles and also discovered many plants. He was the first man to coin the words biology and invertebrate. After the age of 50 turned his interest towards the evolution of animals. In 1809 published the theory called theory of inheritance of acquired character. In the French Science Journal Philpsophie Zoologique. According to his theory said that the modifications gained by the adaption will gradually hand down to generation as a part of heredity with respect to environment which after long period of time changes into new animals.

The major characters of theory are as follows;

1. Effect of environment

2. Use and disuse of organs.

3. Inheritance of acquired character.

 

1.Effect of environment:

Each and every animals are directly or indirectly affect by the surroundings or environment with the change of the environment gradually animals also changes habit or adaptation. Because of adaptation body modifications takes place, such characters either uses continuously will gradually change into developing characters if not in use gradually disappear convert into vestigeal organs.

These after born characters or acquired characters as heredity will continue from generation to generation as a result finally evolved new animal.

2. Use and Disuse of Organs: Continuous use of organs makes them more efficient and leads to their better development. The organism acquires certain new characters due to direct or indirect environmental effects during its own lifespan and these characters are called acquired.

3. Inheritance of acquired character: The character acquired during the lifetime of an individual are transmitted to its offspring.

For e.g.; lengthening of the neck of giraffe.

According to Lamarck, the short neck giraffe had the neck length 35cm and was feed upon the grasses. With the change of time and place started to feed upon the leaves of the herbs. Similarly changed in median leaves and finally upon the leaves of tall trees. During that feeding behavior neck portion was used continuously as a result after a long period of time evolved long neck modern giraffe.

Significances:

1. He was the first man to coin the word heredity and vestigial.

2. Effect of environment is true without which life cycle is impossible.

3. He was the first pioneer to give the evolutionary theory regarding the animals.

Criticism:

1. The development of body organs is only limit in their life time that is new inherited.

2. Wanting of new organs by exercises is totally or manifestly false.

3. Acquired character is the after boned character whereas heredity is genetic character.

Darwinism or Darwin’s theory of origin of species by Natural Selection:

Charles Darwin (1809-1882) was a nature lover and was good English writer. After completing his graduation about five years travelled in his own ship named HM Beagle around the Britain. Again from 1835-1855 travelled nearly for 20 years crossing over European seas and Indian ocean. From that voyage he has collected many animal species. In the same period another young scientist Sir Alfred Wallace was also study about the different nature of beaks of birds in Malayan peninsula. In 1858, Darwin and Wallace combinedly published book origin of species which became highest book sell in the world. In 1859, Darwin separately published the theory called theory of origin of species by natural selection. Similarly in 1871, published the book called Descent of Man which also became second highest book sell in the world.

 

Monumental regarding the theory:

1.Animals are highly fertile yet their totalnumber almost remains constant.

2.Struggle for existence.

3.Variation and heredity.

4.Natural selection

5. Origin of species.

 

1. Animals are highly fertile, yet their total number remains constant:

All the animals have high reproductive rate in their life cycle. For eg; one pair of housefly lay eggs about 6-7 batches of eggs, each batch of egg content 130-150 number of eggs , such egg hatches in 10th day and after 14th day again start reproduction.Therefore till first parent lived number of housefly approximately would be 191 X 10ⁱ⁸ numbers.

If all the generation of the housefly continue their life cycle then in the near future world will be ruled by only housefly which is not happened yet. Although the reproductive rate is very high but in the nature population almost remain to be constant due to various factors.

2. Struggle for existence:

Increase in the numbers of the animals population automatically increases competition in between inters specific and intra specific animals. Due to such competitions develop food chain in which eating and being eaten process continue. As a result after long time only those animals continue their life cycles that can fight for struggle for existence mainly for food and space.

3. Variation and Heredity:

Animals who could fight for struggle for existence only continue their life cycles. Among those animals having best variation will only continue life cycle as heredity, rest of all automatically dies.

4. Natural Selection or Survival of the fittest (Spencer):

Animals that can fight for struggle for existence possess best variation and heredity characters are said to be best of the best animal commonly called survival of the fittest. Such animals Darwin termed as naturally selected animals. After the selection by the nature ready for evolution of next animal.

5. Origin of new species:

From the naturally selected animals after long period of time changes in their morphological and anatomical characters due to various adaptations. As a result from those animals originate new species which is called origin of species.

Significances:

1. Darwin is the second pioneer to give the theory about origin of species by natural selection.

2. Every monumental are directly or indirectly related with the effect of environment.

3. First theory to explain about origin of new species in most simple manner which anyone can understood.

Criticisms:

1. Darwin did not mention about vestigial organs which are found in the animals.

2. No mentioning about mutation because without mutation origin of new species never takes place i.e. by natural selection new species never evolved.

3. Variation whether somatic or genetic because only genetic variation are heredity.

4. If applies to human beings becomes totally failure because of;

a) Human population never becomes constant.

b) Not only struggle for existence other also continue life cycle like beggars.

c)Instead of survival of the fittest in man only arrival becomes most fitted.

 

Neo-Darwinism:

After the dead of Darwin, his followers represented Neo- Darwinism which based upon the genetic character. This theory was developed when gene was discovered in 1901 by American Scientist Margon, Shutton, etc. The origin of species by natural selection become failure because for the evolution of new species should change in the character of the genes.

Mutation is the key character in the origin of species which takes place by;

a) Change in the characters of chromosomes.

b) Change in the number of chromosome.

c) Change in the characters of genes present in the chromosomes.

Neo-Darwinism forwarded many important ideal to explain his theory.

1. Germplasm Theory: in 1886, August Weismann explains about this theory. He explains that the body of an organism is composed of two types of protoplasm, i.e. Somatoplasm and germplasm.

2. Mutation theory: The concept of mutation is given by scientist Hugo De Vries. While he was studying in evening prime rose. The changes in the character of leaves, flowers, coloration of flower etc. are depending upon the character of chromosomes.

Hence for the evolution of any animals, mutation is most or mutation is a raw material for the origin of new species.

3. Isolation: Separation of organisms of a species into several groups or populations under geographical factors is supposed to be one of the most significant factors responsible for evolution.

4. Natural Selection: Animals that can fight for struggle for existence possess best variation and heredity characters are said to be best of the best animal commonly called natural selection. Further, natural selection creates new adaptive relations between population and environment, by favoring some gene combinations, rejecting others.

5. Genetic Drift: The variation in the gene frequency within population, simply because of chance rather than by natural selection is called genetic drift.

6. Gene pool: A gene pool may be defined as the total variety of genes and alleles present in sexually reproducing population. The gene pool may be changed by, mutation, hybridization and natural selection.

7. Genetic Recombinant: The rearrangement of genes that occurs at the time of gametes formation is known as recombination. The recombination is the major source of genetic variations in the population which play a significant role in evolution.

 

Human Evolution:

Phylum: Chordata

Sub phylum: Vertebrata

Group: Gnathostomata

Super class: Tetrapoda

Class: Mammalia

Sub class:  Eutheria

Order: Primate

Sub Order: Anthropridea

Infra Order: Catarrhini

Super Family: Hominidae

Human beings have achieved tremendous development in electronic fields, communication fields and space fields. But unfortunately still now nobody knows the real ancestor.

Scientists TH Huxley was the first who wrote book about the evolution of man in 1863. Similarly Charles Darwin in 1871 published the book called Descent of Man. Similarly their came many scientist who discovered human fossils and wrote books in different ways. It is believed that ape like animals were evolved during Miocene period and man like creature developed in the Pliocene period of Cenozoic era.

On the basis of the taxonomic characters there is no doubt that man evolved from monkey like creature, the common group is Anthropoidea. It is conformed that man and chimpanzes, gorilla, orangutan were evolved from the common super family Hominoidea. Similary on the basis of genetic characters the banding patterns in the gene of man and gorilla looks similar.

To study human evolution in brief can be present as follows;

1.prior to the ape man.

2. Prior to the ape man including pre-historic man.

3. Prior to the prehistoric man including modern man or man of today.

Fig: Human evolution chain

1. prior to the ape man:

Ape man was developed from the Miocene period with having more or less similar characters of the modern man.

Anthropologists Lewis 1930, leaky 1955 have discovered fossil of ape man from the different regions of the world. On the basis of the fossil character some of the ape man is as follows:

Dryopethicus

Oreopethicus

Aegyptopethicus

Ramapethicus

Shivapethicus, etc.

The fossil analyzed following characters;

Almost walked by bipedal locomotion, nose almost flat, forehead flat, arrangement of teeth in the jaws are similar, possess arched palate, cranial capacity varies between 400- 600cc etc.

2. Prior to the ape man including pre-historic man:

After the ape men evolved man like pre historic man nearly from Pliocene period. There are many fossils of the pre historic men. Some the fossils are as follows;

1. Zinjan thropus: leaky in 1959 discovered fossils from Tanzania which analyzed about 5 fit tall, walked almost erect, more intelligent than the ape man, developed communicating ways as well as hunting tools.

2. Anotralpethius African: Antrophologist Prosf Dart in 1924 discovered fossils of child from Australia and later from Africa. The fossils analyzed about 4 fit tall, slight raised of nose bone, development of forehead, etc.

Similarly from the different parts recorded the fossils of the following pre-historic men;

a) Pithecanthropus – Java man

Java man, extinct hominin known from fossilremains found on the island of Java, Indonesia. It is discovered by the Dutch anatomist in the early 1890s were the first known fossils of the species Homo erectus.

Java man was characterized by a cranial capacity averaging 900 cubic cm (smaller than those of later specimens of H. erectus), a skull flat in profile with little forehead, a crest along the top of the head for attachment of powerful jaw muscles, very thick skull bones, heavy browridges, and a massive jaw with no chin. The teeth are essentially human though with some apelike features, such as large, partly overlapping canines. Thighbones show that Java man walked fully erect, like modern man, and attained a height of about 170 cm (5 feet 8 inches).

b) Sinanthropus – Peking man

Peking man, extinct hominin of the species Homo erectus, known from fossils found at Zhoukoudian near Beijing. Peking man was identified as a member of the human lineage by Davidson Black in 1927 on the basis of a single tooth.

Peking man is characterized by a cranial capacity averaging about 1,000 cubic cm, though some individual skull capacities approached 1,300 cubic cm—nearly the size of modern man’s. Peking man had a skull that was flat in profile, with a small forehead, a keel along the top of the head for attachment of powerful jaw muscles, very thick skull bones, heavy browridges, an occipital torus, a large palate, and a large, chinless jaw. The teeth are essentially modern, though the canines and molars are quite large, and the enamel of the molars is often wrinkled. The limb bones are indistinguishable from those of modern humans.

c) Atlanthropus – Atlantic man

d) Homohobilis – Toolmaker man

e) Eounthropus dowsoni- dowsoni man

f) Homo neanderthalenis –Neandenthal man

Neanderthals are our closest extinct human relative. Some defining features of their skulls include the large middle part of the face, angled cheek bones, and a huge nose for humidifying and warming cold, dry air. Their bodies were shorter and stockier than ours, another adaptation to living in cold environments. But their brains were just as large as ours and often larger - proportional to their brawnier bodies.

Neanderthals made and used a diverse set of sophisticated tools, controlled fire, lived in shelters, made and wore clothing, were skilled hunters of large animals and also ate plant foods, and occasionally made symbolic or ornamental objects. There is evidence that Neanderthals deliberately buried their dead and occasionally even marked their graves with offerings, such as flowers. No other primates, and no earlier human species, had ever practiced this sophisticated and symbolic behavior.

 

g) Homo soloensis- solaman

h) Homo rhodesiensis – Rhodesian man.

The common character of the latest Pre historic man is as follows;

1. They walked in almost erect posture.

2.Development of nasal bone, forehead increases the cranial capacity of bone, bipedal locomotion, more intelligent, discovered different metal hunting tools, discovery of fires, know how to cook, lived in families, development of communicating ways, used animal skin as cloth , etc.

3.Prior to the prehistoric man including modern man or man of today:

The latest prehistoric man is consider as Cro-Magnon man which  were lived since 1.5 lakhs years back of become extinct since 15,000 years back. The fossils of this man were recovered by Anthropologist Mac. Gregot in 1868 in sedimentary rocks called Cro–Magnon rocks, first in Germany, Then in France, Czeehkaslovakia. The fossils analyzed the following characters:

1. Height ranges between 5 to 6 fit tall.

2. More intelligent than the prehistoric men.

3. Nose further raise, cheek distinct, fore head distinct.

4. Cranal capacity between 1590-1600 cc.

5. Complete bipedal locomotion, body almost erect.

6. Used animal skin as cloth, lived in colonies or in families.

7. Development of highly sophisticated metal hunting tools.

8. Know how to cook i.e. use of fire.

9. Development of communication or language etc. Before the extinction of Cro-Magnon man, they migrated in three different regions.

After the extinction of Cro-Magnon man came into existence man of today or modern man Homosapienswith more developed character such as; site of intelligence increased although cranial capacity slightly reduced to 1500-1550cc, developed various communicating ways or languages, enter into the age of aluminum age, discovered many technologies in the various fields, completely erect body, etc.

In these manner modern man is also on the ways of changing thus probably in the future will changed into Homosapiensfutureless with further developed characters.

 

Difference between man and Apes

There are a number of distinctive features of human species which make it different from his close relatives, the anthropoid apes (for example, gibbons, orangutan, gorilla and chimpanzee).

1. The human species walks erect on two feet (bipedal). He is terrestrial, gregarious (lives in community) and omnivorous. On the other hand, the apes are semi-erect, for-handed, tree-dwellers and less gregarious. Legs in man are 30% longer than the arms.

2. Hands of man are not specially modified as we find in bats and whales. Thumbs are better developed. Arms of ape reach below the knees. Apes walk with a bent posture and balance themselves on the knuckles of their hands. The hind limbs of the apes enable them to grasp an object. But the feet of man act as a platform and are suitable for palntigrade (walking on the soles of feet) type of locomotion.

3. The thumb of ape is short. In man the thumb is longer and it is more mobile to close in on other fingers. As a result, the hand can be used for a variety of purposes.

4. Bipedal locomotion in man leaves the arms and hand free for carrying or doing things, the movable joints of arms, wrists, hands and fingers afford a great deal of versatility and the forelimbs can be used with great dexterity for handling tools.

5. Teeth of an (incisor, canine, premolar and molar) are smaller and more ordered. The jaws and nose are smaller than those of gorilla. The capacity of the human brain box is 100cc; in gorilla it is 510cc.

6. The space between the two eyes is close enough for distance perception and stereoscopic vision.

7. The retina in the eye of man is provided with cone cells which perceive different colors.

8. In man the brow ridge is not as prominent as in gorilla.


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