MUTUALISM

THERE ARE CERTAIN TYPES OF CLOSE BIOTIC INTERDEPENDENCE AMONG THE SPECIES LIVING IN AN ECOSYSTEM SUCH AS-MUTUALISM, WHICH IS AN ASSOCIATION BETWEEN TWO OR MORE ORGANISMS IN WHICH ALL DERIVE MUTUAL BENEFIT WITH NO HARM TO ANY OF THE PARTNERS. MUTUALISM CAN BE SEEN BETWEEN PLANTS AND ANIMALS AND BETWEEN TWO DIFFERENT ANIMALS.


MUTUALISM BETWEEN PLANTS AND ANIMALS : IT IS AN IMPORTANT ASSOCIATION WITH REGARDS TO REPRODUCTION OF MANY KINDS OF PLANT SPECIES. PLANTS ATTRACT INSECT BY THERE SWEET NECTAR OR COLOUR. THE INSECT VISIT THE PLANTS TO OBTAIN THEIR FOOD. THE PLANTS DUST THEM WITH POLLEN AND THE INSECTS CARY THE POLLEN FROM FLOWER TO FLOWER. PLANTS ALSO TAKE THE HELP OF ANIMALS IN THE DISTRIBUTION OF SEEDS. ANIMALS, AFTER CONSUMING THE FRUITS, DISTRIBUTE THE HARD COATED SEEDS WHICH PASS THROUGH THEIR ALIMENTARY CANAL, IN THEIR DROPPINGS.


MUTUALISM BETWEEN ANIMALS AND OTHER ANIMALS : MUTUALISTIC ASSOCIATES BETWEEN BIRDS AND ANIMALS SUCH AS, THE COW BIRD AND BISON, THE OXPECKER AND THE ANTELOPE,  THE CROW AND THE CATTLE, DISPLAY SUCH RELATIONSHIP. IN ALL THESE RELATIONSHIPS THE BIRDS RENDER CONSIDERABLE SERVICE TO THEIR HOST BY RIDDING THEM TO TICKS AND EXTERNAL PARASITES. THEY ALSO SERVE AS SENTINELS. IN TURN THE BIRD RECEIVES A CONSTANT SUPPLY OF FOOD.


AN INTERESTING EXAMPLE IS BETWEEN THE CROCODILE AND THE BIRD, PLUVIANUS AEGYPTIUS. THE BIRD REMOVES LEECHES AND FRAGMENTS OF FOOD IN DECAYING CONDITION FROM THE CROCODILE. THE CROCODILE OPENS ITS JAWS AND PERMITS THE SEARCH AND THEN FINALLY THE BIRD RECEIVES THE FOOD FROM THE CROCODILE. THE COMMON STARLING BIRD ALSO PERFORMS THE SAME FUNCTION WITH THE SHEEP.


SPONGES GROWING ON THE SHELL OF THE HERMIT CRAB PROTECT IT BY PRODUCING BAD ODOUR. HERE THE ADVANTAGE TO THE SPONGE IS THAT, IT IS CARRIED TO NEW WATERS FOR ITS OWN FOOD. THUS, THE MUTUALISTIC RELATIONSHIPS BETWEEN PLANTS AND ANIMALS AND ANIMALS SHOW THEIR INTERDEPENDENCE FOR MUTUAL BENEFITS.


MUTUALISM MAY BE OBLIGATORY OR FACULTATIVE. AN EXAMPLE OF OBLIGATORY  MUTUALISM OCCURS BETWEEN A HORSE AND CERTAIN MICRO-ORGANISMS. MILLIONS OF CILITATE PROTOZOA AND BACTERIA LIVE IN THE STOMACH AND CAESUM OF A HORSE WHICH DIGEST CELLULOSE FOR THE HORSE  AND PROVIDES 20 PERCENT OF ITS NITROGEN REQUIREMENT PER DAY.THESE INTESTINAL MICRO-ORGANISMS ARE ESSENTIAL FOR THE NORMAL GROWTH AND HEALTH OF THE HORSE.


MANY MUTUALISTIC RELATIONSHIPS ARE FACULTATIVE, I.E., BOTH ARE FAVOURED WHEN LIVING TOGETHER. THOUGH BABOONS AND IMPALAS CAN SURVIVE WELL WITHOUT EACH OTHER, BUT EACH PROVIDES A PROTECTIVE WARNING SYSTEM  FOR THE OTHER WHEN THEY LIVE IN ASSOCIATION. SQUIRRELS FACILITATE THE EXTENSION OF THE HISKORY TREE  BY BURYING THE NUTS, THOUGH THE HISKORY TREE CAN PROPAGATE WITHOUT SQUIRRELS. IN THE SAME MANNER, SQUIRRELS  CAN SURVIVE WITHOUT HISKORY NUTS, IF AN ADEQUATE SUPPLY OF OTHER NUTS IS AVAILABLE.


MAN HAS CAPITALIZED ON MUTUALISM AS BIOLOGICAL  PRINCIPLE IN THE DEVELOPMENT OF AGRICULTURE. DEVELOPMENT OF AGRICULTURE RESULTED IN THE RELATIONSHIP OF FACULTATIVE COMMENSALISMS OR MUTUALISM OF PLANTS AND ANIMALS WITH MAN. AT THE DRAWN OF AGRICULTURE 10,000 YEARS AGO, MAN COULD LIVE WITHOUT DOMESTICATION OF PLANTS AND ANIMALS, BUT AS HE DEVELOPED THESE RELATIONSHIPS HE GOT INVOLVED IN OBLIGATORY MUTUALISM. MODERN MAN OBVIOUSLY CANNOT LIVE WITHOUT THE DOMESTICATED PLANTS AND ANIMALS OF AGRICULTURE, AND MANY OF THESE DOMESTICATED FORMS CANNOT LIVE WITHOUT THE SPECIAL HUSBANDRY PROVIDED BY MAN.