THEMES IN AFRICAN HISTORY

The origin of man;

-There are two theories which explain the origin of Man:

Ø Creation theory

Ø Evolution theory

                             I.            CREATION THEORY

-This theory simply state that “Man was created by God as appears today” He has not changed.

-He was created to be the master of nature and therefore, there is not time man has ever being a slave of nature.

-He was created to be the master of environment like Animals and plants.

-The notion of creation is found in Holly Books such as “HOLLY BIBLE AND HOLLY QURAN”

-In the Holly Bible in Genesis 1:26-39

-In Holly Quran “God breathe out onto the soil and Man was created”

                         II.            EVOLUTION THEORY.

Ø Man and other forms of life have undergone gradual development from simple forms to complex human creature of today.

Ø Evolution is the gradual process of change through which species adapt themselves to the changing of environment and in the period of time developed gradually from simple forms to complex forms.

Ø The profounder/ founder of this theory was “CHARLES DARWIN” in 18^thcentury.

Ø The theory of human evolution tells us by 30 million years ago, there existence a group of primates, these primates were known as “Old world monkey, new world monkey and Apes (gorillas and chimpanzes).

Ø As the time went on some primates like old world monkey and new world monkey became extinct (disappear), only Apes continue to live on Earth.

Ø At about 14-12 million years ago B.C ,Apes became to develop along separate line:-

vChimpanzes and orangutans

vGigantopithecus

vRamapithecus

Ø Also by 5 millions ago chimpanzee and orangutans and Gigantopithecus they became extinct in the earth only remain Ramapithecus. Therefore Ramapithecus is remained group, Also is said to be the eariest known representative of the hominid family to which the modern Human being belongs.

Ø HOMINID- is the biological term means the early Human like creatures with larged brains and ability to walk on two legs as well as making and use tools and language development.

Ø Ramapithecus involved into the following species:

vAustralopithecene

vAustralopithecus

vHomoerectus

vHomosapiens

vMeandarthal man

vHomo sapiens sapiens( Modern human being)

CHANGES OF MAN

Ø The basic factor that influence and condition Man evolution was Environment.

Ø During the Eocene and Oligocene period ( 50 million years ago to 25 million years ago).the environment was characterized by extensive rainforest.

Ø But during Miocene and Pliocene (25millions years ago to 2 million years ago). There were greatly physical and climatic changes on the earth.

Ø Experience with massive faulting which produce ranges of mountains like Alps, Himalayas, Andes, Atlas and Rockies.

Ø At later stage between 1.5-1.2 million years ago similar movement produce the great African lift valley also produce a series of lakes.

Ø The volcanic mountains emerge at this time.

Ø Climatically there was a change from wet to drier conditions leading to the disappearance of forest in most part of the earth and predominant of grasses and thorny shrubs.

Ø These changes of environment forced their ancestor of man to adopt terrestrial life (living on land) instead of living on forest/ trees and to live on land.

Ø This situation was aided/supported by the development of BIPEDALISM.

Ø BIPEDALISM means standing on hind/back limbs, whereby before they use four limbs, and fore limbs using to collect food.

Ø The process of standing on hind limbs enabled the ancestor of man to reach foods in trees by using fore limbs and could easier to see enermies and run away faster.

Ø Also Bi pedalism enable the ancestor of man to use fore limbs to make and to use tools, and its where develop labour process.

Ø Development of labour such as making and using tools involved thinking, thinking led to increase in brain capacity and development of consciousness.

Ø Since labour was in complicated activity it necessitated some kind of communication thus man slowly developed language.

Ø A man born to acquire language.

Ø Tool making was a gradual process which depends on brain enlargement.

Ø Tool making was began in Paleolithic period (old stone age) at this time man made simple stone tools like choppers, hand axes etc. both of this tools was discovered on Oldvai gorge in Arusha.

Ø These stone tools were more improved in middle stone age (Mesolithic period) and late stone age (Neolithic period).

                                                            

WHY AFRICA IS SAID TO BE CRADLE OF MANKIND

Ø Discoveries made point to Africa as the original home of mankind and the principle center of Human evolution. Different discoveries indicate those early human beings are believed to live in Africa. For example, the fossils of a creature named “Kenyapithecus” are believed to be discovered in Fort Ternan in Kenya.

Ø This creature is believed to live about 14 million years ago and belong to a group of Ramapithecus.

Ø Also there was a group of Australopithecus Africanus and Robustus.

Ø The fossils of this creature had been discovered in Krondrai and Makayangsgat, stekfontein and Tang which found in South Africa.

Ø  Also Australopithecus Robustus which include zinjaslopus discovered in East Africa found in Oldvai gorge, Laitoi site in Tanzania, in Kodafrola, Trukana in Kenya.

Ø  Also Homohabilis “Tool making creature” They discovery oldvai gorge, Lake Trukana in Kenya also in Hada Ethiopia.

HOMO ERECTUS

-This creature was completely uplight and widely distributed east Africa, Europe

                                   

AGRICULTURE

    AGRICULTURAL   SOCIETIES

                    Agriculture is the system of cultivating crops and keeping animals. Or, is an adaptation of early farming technique, crop cultivation and domestication of animals (during Neolithic revolution).

The Agricultural systems that were involved in Africa were influenced by

-Climate

-soil formation

-Drainage system

-Relief features.

v There were several Agricultural systems that involved in Africa. These were

Ø Shifting cultivation

Ø Intercropping

Ø Agro forest

Ø Irrigation system

Ø Mixed farming

Ø Terracing

                                                       I.            SHIFTING CULTIVATION.

This was the method of cultivation which involve shifting to a new land when the land cultivated for several season got exhausted, was suitable in low population and plain land it was more practiced in savanna bush land. E.g., kikuyu, Sukuma

                                                     II.            INTERCROPING FARMING

This was the Agricultural system which involves planting different species and varieties of crops on the same field, was good due to climatic change, E.g. Swazi people.

                                                  III.            AGRO-FOREST.

This was the Agricultural system which involves planting trees on cultivated field. Is suitable for soil fertility and it provide shade to crops. E.g. kikuyu, Haya and Sukuma

                                                  IV.            IRRIGATION FARMING

This was Agricultural system which involve the application of controlling amount of water to plant at needed interval, help to grow Agricultural crops, maintain land scape and revegetate in dry area or period of less rain. E .g. Egypt, North Sudan, Tunisia and North Nigeria

                                                    V.            MIXED FARMING

This was the system of Farming that involve growing of crops and raising livestock. E.g. Gogo, Kurya, Nyaturu in Tanzania

-Fulani in West Africa

-Swazi and Nguni in south Africa

                                                  VI.            TERRACING FARMING

This was the Agricultural system which involve the construction of ridges across the slope in order to avoid soil erosion, it is common in high land areas

CHARACTERISTICS OF AGRICULTURAL SOCIETIES

Ø There was increase of tendence of living of permanent and semi- permanent

Ø There was increase population

Ø There was increase modification of natural Environment

Ø Formation of classes in the society and social hierarchies

Ø They practice of land ownership was common

Ø Emergence of trading economies

CONFLICTS IN AFRICA.

CONFLICTS IN AFRICA.

               Conflict, is an active disagreement between people with opposing opinions or principle. This situation leads to actual fighting, which cause death of people and destruction of properties like building, infrastructures. Conflict in Africa began from 1960s, in which most African countries got their independence. Recent years many regions in Africa involved in wars, for example Sudan, Nigeria, Libya and Democratic Republic of Congo (DRC). There are Economic and Social factors for conflicts in Africa. By starting with economic factors for conflicts as follows:

               Massive unemployment, the state of being unemployed, means a situation where by people with qualification lacks job opportunities. Most of African countries became a victim of unemployment. Examples of countries which suffer from conflict like Libya, Sudan. For example in Nigeria gets into conflicts because of Inequality in provision of job opportunity that southern Nigeria are given much priority than northern parts of Nigeria that lead the rise of conflict.

               Natural resources, these are materials such as minerals, forests, water and fertile land that occur in nature and can be used for economic gain. In Africa there are many natural resources but due to unequal distribution of natural resources creates conflicts between them. For example, Libya due to oil, Tanzania and Malawi due to Lake Nyasa, North and south Sudan due to oil. This is initiated by those majorities who do not benefit with resources against those who benefits the resource.

               Foreign Investment, investment means action or process of investing money or material for profit. The surrounding of a place by hostile force in order to blocked it. Due to foreign investment means the investment done by people from another country. Tends to force some indigenous to move far from their settlement hence lead to the rise of conflict. For example in Arusha Tanzania

               Price fluctuation means suddenly raise and fall of price in a particular geographical area. Due to price fluctuation especially when price raise the majority fail to afford their needs. As a result they enter into conflict with their Government, for example Zimbabwe due to oil raised.

A part from economic factors also there are social factors for conflicts in Africa, these as follows:

               Population pressure, rapid increase number of people in a certain geographical area. When the number of people is higher than available resource this lead to the shortage or scarcity of natural resources like land which is mostly used for settlement, Agricultural activities and mining. Whereby due to the scarcity of land influence people to get into conflicts. For example Morogoro in Tanzania this conflict include pastoralist and farmers.

               Religious difference, this means different ideologies in believes, there are Christians and Muslims. Due to this differences lead one religion to be favored by leaders in all aspect of life such as social services like education, health, water and electricity supplier as well as infrastructures, this lead other religion to react against this situation which creates classes and disunity among the people and later on lead to conflicts. For example in Nigeria and central Africa.

               Cultural difference,  especially in tribes differences this create enemity among of them, one tribe seeming that is superior than other that lead fighting, For example in Rwanda Genocide in 1994 is between Hutu and Tutsi that cause death of many people in Rwanda, also in Nigeria is between Hausa and  Fulan.

               Inequalities, this occurs in the society experienced with classes among the people, in area where leader live mostly there is the presence of good social services like infrastructures, education, health, water and electricity while in area where lower class lived there is absence of social services. This situation lead lower class to react against the government later on creates conflict.

                In fact that, conflicts in Africa lead to some effects like mass killing of people example in Rwanda Genocide (1994), lead refugees, destruction of properties like building, also leads to the decline of the economy of a particular country. In order to avoid these conflicts some solutions are to practice true democracy, provision of employment, avoiding religionism, equal sharing of natural resource as well as to avoid tribalism.

              

  

REFFERENCE OF BOOKS.

1.      Conflicts in Africa introduction of global issues (www.globalissues.org>article>http://conflicts).

2.      Conflicts and violence in Africa: causes sources and type (http://www.transcend.org>terms 2011/02).

3.      Conflicts definition and meaning/ Collins English dictionary (http://www.collinsdictionary.com)

GREEN HOUSE GASES

          Green House Gases is a gas that absorbs and emits radiant energy within the thermal infrared range. Green House gases cause green house effect. The primary green house gases in the earth’s Atmosphere are Water vapour, Carbon dioxide, Methane, Nitrous oxide gases cause the green house effect and ozone depression. Without green house gases the average temperature of earth’s surface will be about -18⁰C rather than the present average of 15⁰C.

 According to Mwakalila S, (2011). Green house gases refer to the gases which allow direct sunlight (relative short wave energy) to reach the earth surface unimpeded. As the short wave energy (that is visible and ultraviolet portion of the spectra) heat the surface longer-wave (infrared) energy (heat) in reradiated to the atmosphere. Green houses gases absorb this energy, there allowing less heat to escape to space and trapping, it in the lower atmosphere

Also Green house gases that absorbs and emits radiant energy with the thermal infrared range, Or is any gaseous compound in the atmosphere that is capable of absorbing infrared radiation, there by trapping and holding heat in the atmosphere, green houses gases are responsible for green house effect which ultimately leads to global warming. The following are the causes of green house gases, which are:

          Industrial activities, Industries produces 40% in the atmosphere concentration of carbon dioxide and methane gases by that gases which cause green house effect through destroy the ozone layer and lead to the solar radiation to the earth surface which lead to global warming. Example, cement manufacture contribute carbon dioxide to the atmosphere when calcium carbonate is heated producing lime and carbon dioxide. Carbon dioxide is also produced by burning fossils fuel that provides heat for the cement manufacture processes. It estimate that the cement industry produce about 5% of global man made of carbon dioxide emission of which 50% is produced from chemical processes itself and 40% from burning fuel to the power that process.

          Agriculture activities, divided into two parts which are crop cultivation and animal keeping whereby in crop cultivation due to the use of Agro-chemical and fertilizers contain methane gases which become the factor influence green house gases, for example in pads agriculture whereby there is the use of chemicals and go direct to the ozone layer and lead to destroy it that cause global warming in the earth surface. Also in animal keeping due to keeping large number of animals, example cattle’s produce the organic manure which produce biogases which contain methane gases and go directly to the atmosphere and cause green house gases.

          Mining activities, this is due to the use of bomb to extract minerals from the ground whereby different gases like carbon dioxide, Nitrous oxide are being emitted hence causing green house gases. Also some minerals itself like uranium tend to produce these green house gases like Hexafluoride (UF₆) not only that but also different machines applied during the process of extraction tends to produce green house gases like carbon dioxide. Example Geita Gold Mining (GGM), Mwadui

          Transportation, the transportation sector generating the largest share emission  of green house gases , the green house gases emitted from transportation primarily come from burning fossil fuel like petroleum which include gasoline and diesel for cars, trucks, ships and trains which emits gases like carbon dioxide gas, also emit smoke which lead to increase of carbon dioxide to the atmosphere.

            Deforestation, this involve cutting down trees in the bush permanent this lead to the shortage of plant species which help in absorbing some green house gases like carbon dioxide, so the absence or scarcity of trees lead to the increase the rate of concentration of carbon dioxide into the atmosphere.

          Development of modern weapons, for example nuclear bombs which are mostly used now days in wars. Whereby these weapons tends to emits carbon dioxide which are among the green house gases hence cause green house effect, this weapons used by Korea, United state of America.

          In fact that, although man cause much the occurrences of green house gases but there are natural factors like volcanic eruption, which tends to emits carbon dioxide gases, also green house gases it associated with some effects such as formation of acidic rain, global warming, climatic change as well as loss of biodiversity.

Thanks to Group member Number 13 MNMA  EGH

 REFFERENCE OF BOOKS

1.      Bast, J (2010): Seven theories of climatic change; what Climatic Change?  What is man’s influence?  What do leading scientists believe?  Science and Public Policy Institute.

2.      Mwakalila, S  (2011): Climatic change and adaptation; University of Dare es Salaam.

3.      Waugh, D. (1996): Geography; An integrated Approached. Second Edition, Nelson House Mayfield Road. UK

4.      Karl TR, Trenberth KE (2003). Modern global climate change

CLIMATOLOGY

Figure 1 Concept of climatology;

Ø Is the average condition of the atmosphere near the earth surface over a period of time.

ELEMENT OF CLIMATE AND WEATHER.

Ø Temperature / Solar radiation

Ø Rainfall / Precipitation

Ø Pressure

Ø Wind

Ø Humidity

Ø Clouds

These Elements acted as factors that affect the climate or weather of an area.

THE STRUCTURE AND COMPOSITION OF THE ATMOSPHERE.

Ø The Earth is not quite a sphere, it is technically an oblate spheroid with a radius which varies from 6,356 km at the poles to 6,378.4 at the Equator.

Ø The slight difference is due to the centrifugal effect of the spinning of the planet Earth that causes the Equatorial bulge.

Ø However the Earth is approximately spherical.

Ø The highest mountains are less than 10 km.

Ø Mountains are significance in their influence Temperature.

Ø Atmosphere is a mixture of transparent, odorless gases held to the Earth by gravity as a shallow envelope.

Ø It provides oxygen the vital support system for Human existence.

Ø It allows Temperature condition as thus suitable for life as we know it.

Ø It allows us to communicate by sound.

LAYERS OF ATMOSPHERE.

·      Troposphere

·      Stratosphere

·      Mesosphere

·      Thermosphere

1.   TROPOSPHERE

Ø Begin from 0-16 km from the Earth surface.

Ø Contains water vapour, clouds, dust and pollution.

Ø Pressure fall unstable as a result as the effects of gravity decreases although wind speed usually increase with height.

Ø Temperature decrease with the increase of height.

Ø Support life.

Ø There is a thin layer called “ TROPO PAUSE”  which form upper limit to the earth’s climate and weather. Also marked by an isothermal(equal) layer where temperature remain constant despite any increase in height.

2.  STRATOSPHERE.

Ø Is a second layer beginning from 20-50 kms.

Ø Characterized by a steady of increase in Temperature “ TEMPERATURE INVERSION” caused by a concentration ozone layer { O3}. That absorbs Incoming solar radiation from the Sun.

Ø Winds are light in the lower part.

Ø Pressure continues to fall and Air is dry.

Ø Act as protective shield against meteorites which usually burn out as they enter the earth’s gravitational field.

Ø There is another Isothermal called “STRATO PAUSE”, where the temperature does not change with the increase of heights.

3.   MESOSPHERE.

Ø Is the third layer of the Atmosphere.

Ø Temperature falls rapidly; there is no water vapour, clouds, dust, or ozone to absorb Incoming radiation.

Ø Experience Atmosphere lowest temperature (-90⁰c) and strongest winds nearly 3000 km/hr.

Ø The “ MESO PAUSE” there is no changes in Temperature.

4. THERMOSPHERE.

The temperature rises rapidly with heights perhaps to reach 1500⁰c. athough the Atmosphere behaves in a complex manner and it’s vertical structure is some what complex, measurements of it’s chemical makeup, such as those first made by Regnault in 1852 have shown that the composition of clean Air (Air from which water and unnatural pollutant have been removed, is remarkedbly is constant).

COMPOSITION OF ATMOSPHERE.

GAS                   VOLUME               MASS

N2                        78.09                      75.51

O2                         20.95                     23.15

Argon                    0.93                       1.23

CO2                       0.03                       0.05

Plus trace of hydrogen, hellium, neon, karypton and xenon

PERMANENT GASES.

These are Nitrogen and oxygen make up our 99% volume.

·      Mostly passive in Meteorogical process, oxygen highly active chemical combine with other substance  A rgon not react chemical with other gases varriable gases, occurs naturally:

·      Water vapour

·      Carbon-dioxide

·      Ozone

PERMANENT GASES.

v Water vapour: is important of its response to solar radiation, because change phase, naturally occurring in form of gas (water vapour, liquid water or solid {ice}). It contributes up to a maximum of 4%.

- It’s of course important component of all weather.

v Carbon dioxide: Absorb long wave radiation from the earth; it’s important in the photosynthesis process in plant where by carbon dioxide we exhale is converted into oxygen by plant.

- Oceans contain a large store of dissolved carbon dioxide.

v Ozone: is important constituence non-gaseous.

SOLAR RADIATION.

(ENERGY IN THE ATMOSPHERE)

-The Sun is the prime source energy on the earth.

-Radiates in all directions to space the earth intercept only a fraction (1/2,210- million) of its total output from the distance of some 149,450,000 km.

-The earth receives energy from the sun as an incoming solar radiation {solar radiation}.

Energy is responsible in controlling earth’s climate and weather system.

-Support all forms of life including plant life {photosynthesis}.

FORMS OF ENERGY IN THE ATMOSPHERE.

v KINETIC ENERGY

-Energy which moving atmosphere possesses by virtue of its motion.

v POTENTIAL ENERGY

-Energy which a body of air possesses by virtue of its position owing to the body doing work to overcome the earth gravity.

v LATENT ENERGY

-The heat energy absorbed and held in storage in a liquid or solid during the process of condensation and freezing respectively.

-Energy is required to melt ice (change it’s state) and evaporate water and such energy is released when the water vapour subsequently condenses or the water freezes.

FACTORS INFLUENCING INSOLATION.

The amount of insolation (incoming solar radiation) received by the earth is governed by the following factors

Ø  The solar constant, the flux/ amount of solar radiation, at the outer boundary of the earth’s  atmosphere received on a surface.

Ø Distance from the sun

-When the earth is near to the sun (periphelion) led high amount of insolation received on the earth surface compared to aphelion

Ø Altitude of the sun

-The height above the sea level, when you go far away from the sea level upward the amount of insolation is reduced compared to the same level with sea level.

Ø Latitude

-in tropical and equatorial regions are experienced with high amount of insolation compared to the Polar Regions.

Ø Rotation of the earth

-Lead the occurrence of day (high) and night (low) that cause the variation in amount of insolation.

Ø Cloud cover

-It influence amount of  insolation, it absorb (14%), reflect (35%) and scattering of  insolation.

Ø Albedo

-Amount of solar radiation which is reflected is high in north and south poles compared to tropical region.

Ø Global heat balance

-The balance between incoming solar radiation and outgoing solar radiation.

Ø Green house gases

-like chloro flouro carbon (CFC), carbon dioxide and methane that absorb reflected insolation.

ATMOSPHERIC PRESSURE AND WIND.

-Refers to the circulation of air over the earth’s surface as a result of difference in pressure.

-Atmospheric pressure can be defined as the weight exerted upon the earth by atmosphere. It is the measure of a force exerted by the mass of atmosphere on the surface at a given location especially of temperature and precipitation

WIND

-Is the movement of air in motion from high pressure (low temperature) to low pressure (high temperature).

-The movement of air may be vertical or horizontal

-Wind is the result of differences of temperature and the force that is exerted by gravity as pressure decreases rapidly with height

-Air flow from high pressure to low pressure, because of earth rotation.

v Air flow

Ø In northern deflected Right

Ø In southern deflected left

PRESSURE BELT AND WIND SYSTEM.

There are three major wind system in each hermisphere

vNorthern hermisphere

Ø North east polar winds

Ø South west wind

Ø North east trade winds

vSouthern hermisphere

Ø South east polar winds

Ø North west winds

Ø South east trade winds

vEquatorial