 Animals had been extremely important for the success of humans. The first animal was domesticated around 10,000 BC. Since then, there have been our beloved companions. They have tilled lands, fought wars, and most importantly, animals have contributed to food. Even today, animal protein continues to feed few billion humans. Their contribution does not end in feeding us with milk, poultry and meat. They have provided us with clothing which can withstand the harshest climatic conditions. Along with several benefits which animals have provided us, they did give us one important nemesis and that is diseases. And the most recent one is COVID-19. Hi, this is Gautam and this video is about the geography of pandemics. Now, before we understand what exactly a pandemic is, we need to go back to the foundation of the classification system of organisms. You get the foundation right, it's much, much easier to understand how epidemics and pandemics originate and how they spread. Now, when it comes to classification systems, you have different kinds of classification systems. You have five kingdom classification, six kingdom classification, seven kingdom, etc. Rather than going to the technical details of the classification systems, we'd rather look at what exactly does it mean to be classified into a kingdom. For example, like any classification system you take, you have something called as a plant kingdom. Now, in this plant kingdom, you'll find all those multi-cellular green colored plants that you find everywhere. Now, they have the capacity to produce or synthesize food by using sunlight. Similar to the plant kingdom, you have a huge kingdom known as Animalia or the animals. And of course, we fall under animals along with a large number of organisms who are cousins and distant relatives. Now, one thing about animal kingdom is within the animal kingdom, you have multiple classes and we Homo sapiens fall under a class known as Mammalia. Mammalia or animals or mammals or animals which feed their young ones using memory glands. Now, you can automatically ask a question. Now, what is the relationship between pandemics and discussing which class under animal kingdom you fall in? The relationship is simple. Now, you take any bacteria or virus or any pathogen. If it wants to infect a particular organism, if the two organisms are related, it is much easier for the bacteria or virus to jump from one organism to the other. To put things in perspective, let's take chicken. The point is simple and straightforward. If a virus or bacteria infects chicken, it is much more likely that the disease will infect a duck rather than a crocodile. So, the more closely you are related, the more chances you will get an infection. Now, we get to the story on how we got closer with animals. Even though human beings have stayed in this world for a very, very long time, we really did not have this practice of settling in one place in our entire history. It has been pretty recent. We lived a life of nomads where we moved from place to place in search of wherever we could find food. So, when you move across the forest, you know, you might find a tree which has fruits. You may just gather them and then eat them. At the same time, you find animals. You kill an animal and just by hunting, you try to get as many as much food as possible. So, similar to that, we just kept moving from place to place so that whenever we found opportunities, using that, we tried to gather as much food as possible. Things began to change around 9000 or 8000 BC in a place known as the Fertile Crescent. The Fertile Crescent is of today's Middle East, specifically encompassing parts of Syria, Iraq, Jordan, Israel and Turkey. It is believed that this is the first place in which the hunters and gatherer human beings began to settle down and start practicing agriculture. This brings us to the first point in geography, proximity. This brings up a huge change in dynamics. Now, before this, we did come in contact with wild animals but not frequently. Once human beings begin to settle down, you have large number of human beings in a small area. At the same time, animals begin to multiply and animals always stay with human beings. This provides wonderful opportunities for diseases to migrate from animals to human beings. The first pandemic possibly started in the Fertile Crescent which we don't even know whether it was documented. As far as it has been documented, our animal friends did provide us with a lot of gifts. As you can clearly see, they pretty much have everything in the textbook, starting from measles to tuberculosis to smallpox and there it is, influenza flu. Enough to jump to the definition of what exactly is a pandemic as defined by the World Health Organization. A pandemic is an epidemic occurring worldwide or over a wide area crossing international boundaries and usually affecting a large number of people. The point which you need to know from the definition is that the definition does not include or talk about busy severity. A pandemic can be very much global but at the same time, it may not be very severe. Of all the pandemics in the ancient and medieval world history, the most important pandemic which frequently occurs or captures the world imagination is the plague pandemic which affected Europe. Termed the Black Death, it pretty much wiped out half the European population between 1330s to 1360s. Plague would continue to revisit Europe multiple times in the 15th and 16th century. Its impact can be clearly seen in the paintings of that age. If one strives for analysis in all those multiple events, one can definitely come across two important parallels. That brings us to the second topic of geography, cities. Cities have high population density where people live very close to each other and whenever a pandemic begins to spread, it's always the cities which get affected or put it in a better way, it's the cities which get affected first and it's from the cities that diseases begin to spread or even further. And moving on, it brings us to the third important topic, transport networks. The importance of transport networks can be clearly seen in the case of ironic plague. If you look at how the disease begins to spread from one particular point to another like A, B and C, you can see a clear transition where all those nodes are interconnected and when people travel from one place to another, either they move through land or through the ocean waters, they clearly carry along with them. So if the area or the region which is under discussion is densely populated and strongly connected across transport networks, it has always seemed to be an epicenter for pandemics or at least an important receiver. If you live away from coastal areas in hinterland or you live in mountainous terrain or in deserts, the importance of pandemics or the impact of pandemics has been much less significant. The fourth geographic parameter is isolation and to understand isolation, we need to go back to 15th century. Human beings have colonized pretty much every continent but there was one minor problem. People who lived in the continents of Eurasia and Africa simply believed that it was the entire world. They did not know that they had four other continents, North America, South America, Australia and Antarctica. All of this was about to change in the late 15th century. A sailor named Christopher Columbus decided that he would find a new trade route to India by travelling westward. Columbus was right that you can find India except that he did not know that America's stood in the way of India. The discovery of continents would change history forever but that's a discussion for another video. Using this historical context the lands which was discovered after 1492 were termed the New World and all the others were termed the Old World. Take a look at this table. If you look at the list of domesticated animals you'll find that except for two. All of them are present in the Old World. So you can ask me what is the big deal? Well, there is relevance. Even though diseases spread from animals to human beings, over a period of time it also gives you a simple advantage. Let's say that you stay in livestock or domesticated animals for 200 to 500 to 1000 years. Over a period of time when you stay with animals even though diseases might spread to human beings at the first instant many human beings might die but over a period of time several decades and centuries human beings begin to develop a certain level of immunity for the diseases which the animals spread. Now if you look at the domesticated animals all of them or most of them is present in the Old World. So people in the Old World have immunity to those diseases. Now think about this. The people in the New World that is North America and South America have no exposure to zoonotic diseases or the animal diseases at all. So when people began to migrate from Western Europe and Africa to North America and South America along with a lot of things or along with the threat of colonization they did bring in a large amount of diseases. To be honest compared to more than the threat of colonization, military and guns more people in the Americas died simply because of diseases. The geographic factor being isolation. They were isolated from zoonotic diseases so when suddenly a disease comes you don't have the immunity for that. All our discussions of pandemic so far has been either in the ancient world or medieval worlds. Now coming to the modern world things take a new turn in the 18th century and the late 19th century or should I say the long 19th century. There is a reason why historians call it the long 19th century because of industrial revolution and the globalization of the worlds. To put things in perspective let's keep industrial revolution simple. For the first time humans start to incorporate machines in factory production or the process of production. Once machines become part of the production process productivity begins to increase tremendously. Now that is the biggest thing. Now once you begin to put machines on your machines or working in factories you need large number of workers. And where do workers come from? Well they come from rural areas. So in cities in 19th century when cities begin to industrialize in Western Europe large number of people move from rural areas to urban areas. And once people begin to migrate you clearly know that they really do not have large amount of salary or income being a worker. They begin to live in shanty conditions and poor conditions and that leads to the proliferation of slums. What used to be a thousand cities begins to become million cities where each city begins to house more than a million people starting from London. And these places of extremely high density become important for spreading diseases. You can look at the statistic. You take the 19th century every 20 years or every 24 years you will see one major pandemic which is spreading across entire Western Europe and possibly even moving to the Americas. The primary reason being industrialization. By the end of 1900 except for a very small portion of Africa Africa gets colonized by European superpowers. Now if you take by 1900 pretty much the world map is set and all parts of the world are interconnected between 1880 and 1900 the amount of ship traffic increases by 10 times. That is when we had the first wave of globalization where all parts of the world get interlinks. Now why are we stressing on 1900 you know when COVID made news all you know all the news media were actually very specific on one particular pandemic that is a Spanish flu. This Spanish flu began to spread in this global in the yesterglobalized world in the year 1918 and it kills more than 50 million people. And it was a crude shock to the human supply chain and human globalized system. After first World War One the biggest challenge which we faced as a civilization was World War Two. But post World War Three if you look at the number of diseases which occur both epidemics and pandemics there has been a slight change in occurrence and increase. So we need to appreciate why these things have happened. Human population growth has seen tremendous growth since 1945. If you have large number of people then it does lead to few challenges. To make sure that food production keeps pace with population growth the production systems had to change. We began to have large scale industrial farms. Think about it when you put so many animals together you give more chances for viruses and bacteria to move from one animal to another. For example from a cow to a chicken to a pig. When they move between different animals they have more chances in which the viruses could mutate and they become even more powerful. Apart from that we have also had large scale proliferation of wet markets. And in the last 25 years we have seen so many epidemics starting from H1N1, avian influenza, SARS, Ebola and Zika. When it comes to pandemics one important point is very easily ignored. When we saw the definition of the World Health Organization as a definition of pandemic we saw that there is nothing on disease severity or how fast a particular disease can spread. You know things in the last 25 years why pandemics have become they have the ability to move fast is because of the technology which you developed in air transport. But there are certain diseases which may not spread extremely fast but they do have an everlasting impact. For example in the year 1959 a virus was isolated from an individual. You know when it was first isolated it was considered not to be extremely damaging but later with developments in 1960s, 70s and most importantly 1980s it was identified and properly said that this virus human immunodeficiency virus can cause AIDS in Homo sapiens. And similar to many other zoonotic diseases human immunodeficiency virus HIV was transferred to human beings by our close relatives chimpanzees and primates. The reason why we stressed on AIDS or you take the case of malaria is that pandemics have mostly existed. What we need to agree is the challenges which lie ahead of us. After COVID-19 the wet markets in China have come under increasing scrutiny for the sale of wild animals and it is believed that measures will be taken. We cannot stay isolated anymore and human population has increased so much that consumption patterns are not going to change anytime soon. This will only increase humans competing with animals for resources leading to more deforestation and aggressive conversion of wildlife areas into human landscape. When there is more and more interaction with wild animals threat of new diseases would only increase with time. And remember old pandemics do not simply disappear. Plague does come back in countries like Madagascar and Peru and new diseases would continue to arrive. The point is every single time pandemics have devastated populations we have jumped right back in. There is no reason to believe that things will be different from COVID-19. Whatever be the challenge we have done it many times and we will continue to do more. Animals are extremely important. They have been indispensable for our success. Corona is just a heads up that apart from deriving benefits from them we also learn to respect them. After all who is a man's best friend?