Some questions and answers
I was wondering if people that are blind their whole lives have dreams. If they do dream, can they see things or is it just sounds or feelings? There are 2 answer(s) for this question. View answers | Submit an answer Yes, research and testimonies of blind people say that they do infact! Dreaming makes your recall memories that may be visual, auditary, olefactory, touch or taste. We have visual dreams, because a large part of our memory is filled with visual images. However, the memories of blind people are stored with inputs from other senses. These memories are often connected with emotions, and blind people experience them too. Infact, research says that 1) If a person was blind from birth he hardly has no visual impressions in his dream. He may however, for example : dream that he is walking around the house touching the furniture as he goes by and he feels happy that his children have come home, by hearing their voices. 2) If a person lost his sight during his lifetime, the amount of visual information in his dreams will depend on when he lost it. A person who lost his sight before 5 years may hardly have any visual dreams when he reaches 40. However, a person who lost his sight 5 years ago will still have vivid visual perceptions in his dreams. This group of people may infact create visual memories through touching and feeling objects which they later recollect during dreams as visual perceptions. This question has an analogue to animals like snakes , bats which have very poor or no sight. However, it has been researched that even the most primitive animals like fish experience REM sleep. Categories: Human Body. Add to my favourite | Edit favourites | Email alert | Edit alerts | Send to friend There are 1 answer(s) for this question. View answers | Submit an answer Cooking has more than one advantageous , even to the cave man. 1) Raw food, especially meat, carries parasites and organisms that can make you ill. Cooking easily kills these organisms. Over decades, humans must have observed that people eating hot food are sick less often than people eating uncooked food, hence making this a social custom 2) Cooking makes the food tender. The proteins in food (especially meat) break down and makes it easier to eat. 3) In addition, the fire at the hut always kept the wild animals away, which was an added advantage. All these factors made cooking very popular. Possibly, (though I have no evidence of it, and I even doubt it) humans have evolved a little to adjust to cooked food. This may not be true if cooking grew only 40K years ago. Other estimates say that cooking existed even before homo-sapiens (millions of years ago) In this case, we have probably evolved our bodies, and digestive systems to the different ( and less taxing) demands of cooked food. Categories: Human Body. Add to my favourite | Edit favourites | Email alert | Edit alerts | Send to friend At school we have been learning about metals reacting with acid. I had a look at the periodic table and I saw that pottasium (K) was an alkali metal. I also knew that bananas are an excellent source of pottasium. So why, when I eat a banana, does the hydrochloric acid in my stomach not react and make me explode? Felix, 11, Norwich There are 3 answer(s) for this question. View answers | Submit an answer I agree with mmm Pottassium is not found in bananas in the elemental form, which is very reactive. It is instead found as a salt. Possibly as KCl or the salt of an organic anion. Look at it this way. Pottassium is so reactive, that it already reacted with something in the banana and formed a very stable potassium salt. So it doesn't react with HCl in the stomach. This stands for all other metals that the body requires, I believe. They do not come in elemental form. Last edited on: 2009-10-05 19:45:18 Categories: Human Body. Tags: stomach, alkalis, Acids, banana. Add to my favourite | Edit favourites | Email alert | Edit alerts | Send to friend There are 1 answer(s) for this question. View answers | Submit an answer Breath is released from your body at 37.5 C The temperature outside your skin is normally lesser than that. So, the skin ought to feel warmer when you breathe on it. So why does it feel colder when you "blow" instead of "breathing"? I thought a lot, and I can come up with two hypothesis. 1) There may be some perspiration/sweat/moisture on your skin, which evapourates when you blow on it. This makes it colder. This is similar to the effect of a hot wind. Even though the wind is hot, if it evapourates sweat efficiently, the net of the two effects may cool the skin. 2) The second reason is linked with human evolution. Wind has almost always been dangerous for cave-men. If you are out in the cold wind, there is a considerably increased chance of you dying out of cold. The body recognises this, and we have evolved mechanisms to recognise pressure on our skin as wind. The brain exaggerates the cooling affect of air on the body if it applies considerable pressure on the skin, and tells us that this can be dangerous. 3) There may be another reason. There is always a warm insulating layer of air near our skin. The wind removes this layer, hence exposing the skin to the colder air outside. Even if the air we blow is warm, after it passes the body, it brings in the cool air from outside. Student in Electrical Engineering, Indian Institute of Technology, Kharagpur I have noticed, as others may have, that as a race humans have everything done for them; travel (cars, planes etc.), hunting (guns, breeding food etc.), and also there is no longer a need too compete for homes (we can simply build more). is there any need to evolve any further? have we reached our final stage in our long evolutionary chain? There are 1 answer(s) for this question. View answers | Submit an answer Wow, this is a very interesting question. Infact, it is agreed upon by the scientific community that evolution does happen quickly in small groups of people, when the pressure to change is high. That is probably how the human species evolved from another primate in a small area in Central Africa around 200,000 years ago. Infact, most species probably undergo times of large changes, and then times of relative stability in gene structure. As of yet, we dont know of any significant threat to human existence, by such risks strike quickly and often without warning. In that case, humans would be forced to evolve or dissappear. Small incremental changes also seem to be happening, in human society, but not fast enough because it doesn't seem to be a life-death matter. Another possibility is that we will get to know our gene structures and how to manipulate them. Through this mechanism we will "evolve" , though this may itself pose risks to the stability of society. People would have to set quotas for increasing-- say intelligence -- in one generation, strict rules, and constant monitoring to see that the system of man-made mutations becomes successful. This would mean that skies are the limit for us, as we can make these mutations and test them at a much faster rate, maybe even through computer simulations( and eliminate the ethical aspect of it). These computer simulations may themselves become people, and we will be like god. But thats not the point. Thats a completely different topic. But yes, evolution as we know it is over, or will take too long for us to observe (in case there is any unforseen disaster forcing us to change) Categories: Human Body. Add to my favourite | Edit favourites | Email alert | Edit alerts | Send to friend 
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Is This The End of Human Evolution? 
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