why do we have to have deserts?
553344
They are a natural part of the environment. If you are proposing getting rid of them, I would like to review your plans first.
104095
Because back then in the desert long time ago, they didn't have water to bathe
92526
Adaptation, which means that they develop special roots and leaves that make them more prone to survive. Such as some plants have waxy leaves in order to withstand high temepratures and various other conditions. In deserts, some plants have very long roots, which affects if there population is random or very populated.
566412
It is very easy Deserts are sand, dunes, diferent kinds of cactus, small bushes, some animals like lizards, insects variety of them, and you can add an Oasis to make it more interest in in the Oasis there are Palms a few, water, you can put a small lake. tents, camels form a caravan in the desert.
17806
It should be noted that you are salty. We have a natural salinity that is important to maintaining homeostasis. Any disruption of our salinity can cause serious metabolic and physiologic problems.
550377
1) Sand grains are too heavy compared to bits of dust. Gravity overcomes cohesion and adhesion in their case. Dust, on the other hand, is light enough to get blown around by the breeze your legs create when you walk through the room. As the bits are blown around, they collide with each other and get hung up on each other. As sand gets blown around, it just falls down again.\n\n2) Also, unlike the building blocks of dust bunnies, sand is not dead cells shed from humans and other animals. Most of the dust your body produces probably has enough skin oils to create a little bit of stickiness.
695255
one reason may be that humans don't go running through the bush as other mammals to. onther reason is in the genes. Some mammals may have genes the control the growth of hair in some species. \n\nBut i like the thought of the first one. if we were having to run and catch our food or we had to sleep on the ground our hair may not be allowed to grow as long.
9475
I don't have any solid research but I imagine there were at least a few general reasons:\n\nTo spread out a kingdom because individuals and their livestock needed more land, OR to accomodate growing populations in a certain kingdom/city/empire.\n\nTo provide a safer buffer from enemies, that is, cities in the center of an increasing territory for better protection.\n\nTo secure resources or trade routes\n\nTo convert other people to the expanding religion\n\nTo populate newly/randomly discovered territories\n\nI am editing now, I suppose those things could have been the reason in the very earliest of times but in prehistoric societies, I bet survival sums it up pretty well. Maybe not expansion but certainly the nomadic thing...pick up and move to beat the weather or a threatening pack of animals, to find food or land appropriate to grow food and support livestock. Territory would certainly have had something to do with it, if there was a serious enough pissing contest with a threatening enough adversary, such as an unfriendly neighboring clan, a settlement of people might pick up and move to give themselves more safety by giving the big guy wider berth.
560833
why cant we have both?
1167318
The need for research is a small one because we could certainly get by without it. Research could however be advantageous because characteristics of these plants and animals could help with medicine and science if understood since they are designed to survive in extreme conditions. Also some will go extinct and we should try to understand them before that.
1115641
If it hits sand, it will often make glass.  It makes the ground very hot for a short time, having so much moisture around it draws the heat away quickly.
466356
I'm not sure about the Sahara specifically but in most deserts if you see a desert plant, such as a cactus, it generally indicates the presence of a small amount of hidden or trapped water underground. This is why no one in a desert would dig for water in a place that does not have a plant in it. It would be a waste of time. So it indicates the presence of water.
1139795
Err you want proof?\nThe Continent of Africa is turning slowly but surely into a vast uninhabitable desert.\nNot fun for the animals let alone the people!\n\nSomething to think about next time you use your energy wasting tumble-driers!  That's why there's Wind & Sun, not because hanging your washing out MAKES YOU POOR!\nOnly an American could come up with a Crook o S**T like that!
875899
I'd say because humans aren't camels...we don't store food that we can easily use for energy later.  Also, their stomachs are bigger, and probably there are a lot of psychological issues: they get hungry when somehing goes wrong or right...whatever it is that makes them want to eat so much.  And then some fat people just have bodies that won't process food correctly, no matter how much they eat.  Some probably eat junk food...Lots of reasons, I'm sure.
530008
Because our body just like every other living thing needs to excrete waste and other harmful chemicals in our body, and things that are unnecessary.  If we didn't, we'd either die, or our bodies will turn everything we eat into fat or something...
706126
Yes, there are actually quite a few insects and animals that don't drink water.  They get the water they need from the food and plants that they consume.  Very handy for desert animals.
228093
OMG...this is a very sad question. The reason why gloval warming NEEDS to affect the earth is because without it, we would all DIE. Think about it, what would we do if there was no heat at ANYTIME. We would all die because we would all freeze to death. Besides in order to keep anything alive we need Gloval Warming. The food we eat need it, the water need it, the plants, animals everything and everyone needs it.