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Evolution has fit out animal with arms and legs of all shapes and sizes — but is one case of limb more important than the other ? The answer lies in a different question : What species are you talking about ?
" Animals last in different environments . They do different things ecologically,“John Hutchinson , a prof of evolutionary biomechanics at the Royal Veterinary College in London , told Live Science . " What we can do is look at the pattern we see in nature through sentence and see how legs and arms have evolved , and that will give us some cue as to the importance of leg and arms . "
Humans are bipedal, which means they walk on two legs instead of four.
Let ’s begin with humans ( Homo sapiens ) , which are two-footed , meaning we use only two legs to walk , instead of four . As a result , it would probably be more difficult to survive without legs than without arms , particularly in the absence of mobility economic aid for handicapped people , such as prosthetics and wheelchair .
link : Which animals have the long arms ?
" I would say human race are an example where we ’ve emphasized our legs — they ’re much bigger , they ’re much longer , they ’re stronger,“Matthew Ravosa , director of the Center for Functional Anatomy and Evolution at Johns Hopkins University School of Medicine , told Live Science . " So I would say we fall into the leg category . "
Humans are bipedal, which means they walk on two legs instead of four.
However , mass with both leg and arm amputation have shown it is possible to thrive in the absence of sealed limb , researchshows .
Perhaps the severe example of a leg - driven creature in story , though , wasTyrannosaurus male monarch . These dinosaurs hadfamously puny blazon : A 45 - ft - long ( 13.7 meters)T. rexwould probably have had only 3 - foot - long ( 0.9 m ) limb , consort to theUniversity of California , Berkeley . To put that into view , that ’s like a 6 - foot ( 1.8 m ) human having arms that are a measly 5 inches ( 12.7 centimeters ) long .
" The earliest member of the groupTyrannosaurus … had long arms just like most carnivorous dinosaurs , great claws , three fingers , and so forth , " Hutchinson said . " So they were n’t especial in their forelimb ; they were pretty normal . But as we move through the chemical group , closer and closer , subsequently in metre towardT. Rex , we see that gradually , the forelimb get reduce . "
It is likely that these carnivores evolved to apportion more of their eubstance mass to their heads — more specifically , to their jaws , to snap down on prey , Hutchinson said .
But for fowl , coat of arms — or , more precisely , wing — are vastly more important than their peg . raspberry wing are essentially modified arms that are adapted for escape , fit in to Ravosa , and they ’re often the largest part of a flying bird ’s body . For example , the planetary millstone ( Diomedea exulans ) has a wingspread of roughly 11 feet ( 3.35 mebibyte ) , while its trunk is just around4.25 feet(1.3 m ) long from beak bakshish to track . One reason you do n’t often see birds with maul wing is that " it really stymie their ability to be successful and they … expire very promptly , " Ravosa said .
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The exception to this blueprint is flightless doll , " which very often reduce their front limbs unless they ’re doing something else with them , like penguins using them for swimming , " Hutchinson said . " But that ’s flight underwater , more or less , so that ’s kind of cheating . "
Some specie do n’t bet on legs or arms — because they do n’t have any . From Snake to worms to eels , many species haveevolved to become limblessbecause it reserve them to better catch prey through constriction or move faster through their environs , where special appendages may actually get in the way , according to theFlorida State Parks Department .
" That ’s very common , really , that front and hind legs are not important at all , " Hutchinson enjoin . " Plenty of animals again and again — from fish to snakes … have reduced all four limb . "
