Reprodct(A) Essay, Research Paper
REPRODUCTION: A-Courting to Nature!For some time she had watched his movements, appearing coyly in hishaunts. And now, had it paid off? Doubtless, he was in love. Hismuscles were taut; he swooped through the air more like an eaglethan a Greylag gander. The only problem was, it was not for her thathe then landed in a flurry of quacks and wingbeats, or for her that hedashed off surprise attacks on his fellows. It was, rather, foranother – for her preening rival across the Bavarian lake. Poor goose. Will she mate with the gander of her dreams? Or willshe trail him for years, laying infertile egg clutches as proof of herfaithfulness? Either outcome is possible in an animal worldmarked daily by scenes of courtship, spurning and love triumphant.And take note: these are not the imaginings of some Disney screen-16writer. Decades ago Konrad Lorenz, a famed Austrian naturalist,made detailed studies of Greylags and afterwards showed nohesitation in using words like love, grief and even embarrassment todescribe the behavior of these large, social birds. At the same time he did not forget that all romance – animal andhuman – is tied intimately to natural selection. Natural selectionbrought on the evolution of males and females during prehistoricepochs when environmental change was making life difficult forsingle-sex species such as bacteria and algae. Generally, thesereproduced by splitting into identical copies of themselves. Newgenerations were thus no better than old ones at surviving in analtered world. With the emergence of the sexes, however,youngsters acquired the qualities of two parents. This meant thatthey were different from both – different and perhaps better atcoping with tough problems of survival. At the same time, naturehad to furnish a new set of instincts which would make “parents”out of such unreflective entities as mollusks and jellyfish.. The peacock’s splendid feathers, the firefly’s flash, the humpbackwhale’s resounding bellow – all are means these animals haveevolved to obey nature’s command: “Find a mate. Transmit yourcharacteristics through time!” But while most males would acceptindiscriminate mating, females generally have more on their minds.In most species, after all, they take on reproduction’s hardestchores such as carrying young, incubating eggs and tendingnewborns. Often they can produce only a few young in a lifetime.(Given half a chance, most males would spawn thousands.) So it’s nosurprising that the ladies are choosy. They want to match theircharacteristics with those of a successful mate. He may flap hiswings or join a hockey team, but somehow he must show that hisoffspring will not likely be last to eat or first in predatory jaws. Strolling through the Australian underbrush that morning, she had
seen nothing that might catch a female bowerbird’s eye. True,several males along the way had built avenue bowers – twin rows oftwigs lined up north and south. True, they had decorated theirconstructions with plant juices and charcoal. Yet they displayednothing out front! Not a beetle’s wing. Not a piece of flower. Then she saw him. He stood before the largest bower and in his mouthheld a most beautiful object. It was a powder blue cigarettepackage, and beneath it there glinted a pair of pilfered car keys.Without hesitation she hopped forward to watch his ritual dance. Males have found many ways to prove their worth. Some, likebowerbirds, flaunt possessions and territory, defending theseaggressively against the intrusion of fellow males. Others, likemany birds and meat-eating mammals, pantomime nest building orotherwise demonstrate their capacity as dads. Still others,however, do nothing. Gentlemen may bring flowers, but most malefish just fertilize an egg pile some unknown female has left inunderwater sand. For a fish, survival itself is a romantic feat. For other species, though, love demands supreme sacrifices. Shortly after alighting on the back of his mate, the male prayingmantis probably had no idea what was in store. This would havebeen a good thing too, because as he continued to fertilize hispartner’s eggs, she twisted slowly around and bit off his head. Shecontinued to put away his body parts until well nourished and thusmore able to sustain her developing young. Luckily for most species, the urge to mate come on onlyoccasionally, usually in springtime. For love can hurt, particularlyif you intended has difficulty telling a mate from a meal. Pity thepoor male of the spider species, Xysticus Cristatus, for instance.His only hope of survival is to tie a much larger female to theground with silk thread, and keep her there. Every time a moth releases its attracting scent, or a bullfrog singsout its mating call, these animals are risking a blind date with somepredator. Such alluring traits have long puzzled scientists,particularly those which seem not only risky but useless as well.Why, after all, should a frigate bird mate more if he puffs out anextra large red throat sac? How does ownership of such a thingindicate a superior individual? Until recently, the question stymiedbiologists, but then researchers in the U.S. and Sweden announced apossible answer. While studying widowbirds, among whomextravagant tail feathers are hip, they discovered that thelongest-tailed males also carried a lower number of blood parasites.Sexual ornamentation seemed to be a means by which males couldshow of superfluous health and energy. All of which may bring us to fast sports cars, flashy clothes andother accessories of the human suitor. After all, if he can afforddinner at the city’s most expensive restaurant, chances are he couldfinance a baby too.