Wikipedy.com                                                                                           Online encyclopedia

   Home     Add article      About

 INDEX

Aging, facts about aging

When animals grow old, noticeable changes take place in their appearance and the way they function. For instance, in man the skin becomes wrinkled and the hair gray. A person's memory becomes poor and he cannot use his limbs so well. This happens in all warm-blooded animals: mammals and birds. They lose their vigor and adaptability.

Aging, facts about aging
The possible life spans of a few mammals. The smaller the animal the shorter usually its life spans. The average life spans of these animals are much less

As they get older, most creatures are less able to adapt themselves to changes and influences in their surroundings. They are no longer able to cope with certain unfavorable conditions, so that they become more prone to diseases and disabilities, particularly to the effects of non-infectious diseases. Excessive cold and damp, or too little food, leave an old animal more vulnerable than a younger one. At the same time, as these effects take place, the creature can take less exercise.

Among the mammals there seems to be some link between size and life span (length of life). Smaller animals age more quickly. Elephants are known to live for up to 70 years, horses up to 40 years, cows 30 years, dogs 20 years, mice only about 4 years. These are maximum ages. Even more important seems to be brain size. Man, who has - in relation to body size - the biggest brain of all mammals, commonly outlives the elephant.

Birds generally have even longer natural life (and big aging) spans than mammals of equal size. Parrots and eagles, for instance, can probably live for over 100 years. Coldblooded amphibians and reptiles live even longer, in relation to size. Frogs and toads can pass the age of 20, while giant turtles may live nearly 200 years.

Wikipedy.com ^@ - Online Encyclopedia