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J i; geience Explains Tkat Man's Elongated First L I : ''(Hun to Stand . J ' I (MH0lfc. Jf JIS11 lA I W His Brain fCIENTCE has discovered that man's V big toe is the feature which first Y made him really human, which now 'l4j distinguishes him from jvpes and all the lower animals and which has set him free Jurlug his evolutionary history to develop !j& his great mental powers. i : Professor John C. Merriam, of the Uni ' J jrersity of California, expressed this inter- - J tins vlew dur,n& a recent address before the National Academy of Sciences, explain- ug the descent o"f man as read from the geological record. ' 4N "In the foot of man, with the samo fun 1( Omental plan seeu in the apes," said professor Merriam, "we find an extreme 3 modification rarely duplicated in verte H borates, in that the normally short first X ilglt fbig toe), while retaining the normal 3jj aumber of phalanges for mammals, has tfeen groat ly enlarged and elongated until equals or exceeds the longest of the :M other digits. This extreme modi- flcation of the human foot is clearly to be r$ coupled with the specialization of the whole limb for running in a long-legged -"a two-footed form, running noi-mally with iverted toes." 'I a little farther on Professor Merriam, iplalning the bearing of the very pocu , Ikr human foot and big toe upon the de- yelopment of the human brain, said: jf 'I "It seems that we must set the human 2 lype off as very unusually modified for the fecial function of bipedal locomotion so I necessary if the hands are to be set freo to i pErve the liead." Few people probably stop to think of the t; Importance of the big toe. If they do they ijrlll realize that it is this featuro which enables a man to stand erect, to attend to' his work efficiently, to run and walk, and '3 to perform most of his remarkable feats I of endurance and agility. Professor Merri jim's address will help us to understand Iwhy the big toe has come to play such an important part in our development This study of man's big toe is an effort to make clearer the difficult subject of evo lution Most of us understand in a gen eral way that the theory of evolution is ac cepted by science, that man has evolved .from lower animal forms and that among this more immediate ancestors were forma 'resembling the existing monkeys and apes. Pewer perhaps understand that there are differences between man and the ape which jfhow that this creature is following a dif ferent line of development and that man ' JPtas lived on the earth about as long as the 5 justing apes, during which period no ape jjj jhas shown the slightest tendency to devel -jOp Into a man. It has been argued that :,nan started to evolve towards his human j orm many stages earlier than the existing vjjpes or monkeys. Some of these stages $ ;bave been lost to sight and can only be re i placed kypothetlcally. The evidence indi tes that a little animal similar to the mur marked the point where man's line ancestry started out. Other branches, king a different line from this point, de sloped into the monkeys and apes. Such observations as Professor Mer am's concerning the importance of man's Is toe help to explain the course of man'3 Glutton during those countless ages in Mch he has grown from a little lemur- or monkey-like animal. Professor Merriam says that man's rela Dnship to the anthropoid apes is evident id that it is more, important to study the fferences between the two thnn the sim iritles. The most striking contrasts between an and the apes are the shape and size the head, and after thai come the differ- ? P i ences in the extremities of the legs- jif&S they can hardly be called feet in thj JWW0M 'apes. The brain capacity of a gorilla, SSifiS the largest ape, is under thirty-six PSfeSJSlfe cubic inches, while that of an in- j0SWm telligcnt male American is WlHwW? ninety cubic inches, and vMWM even the brain of a Ved- ,1! dah. woman of Ceylon, MMmMM one of the lowest of yMiMmMm human races, meas- BMm imW ures fifty-seven cubic Difierences in skull are marked by the MkSnM enormous and very mS!Wm J prominent jaws of the WmmMmW' J apes, the relatively gWS Wi very high top head of XWmSMlkMBmfm the man and by the position in which the MMlW4iMMMWr- head is placed on the mKmmWWiW jm Professor Merriam SWWJ 'flfewmik is fully as marked as BSs ' W$3& in the skull. Tne dif- fP-' .i v t- ' ffW feronce in limbs am iiPMf not merely in degree, but in kind and tunc- forelimbs ' are the principal structures Iho ApCf Vhose Skelototr for moving about Most Nearly Rccemblcs a Man Which is by springing Except That His Foot Is through the trees. To Rally , ,a cHa?f . Specially , . -t Adaptable for Living in the some extent, however. Trce3 and Not fop Valki the forohauds of the on tc Ground. The hind limbs of tho apes are used for grasping and the feot servo as hands. Tho ape's feet have a big toe acting as a thumb in a more marked degree than the first fingers of his forehands. In man the relatively long posterior extremities are used solely for walking or running. Tho human hands with their wonderful op posable thumhs serve the head mainly. They are sometimes used incidentally to help in climbing or in crawling on the ground, but their primary function is now to carry out the conceptions of the mind. The opposable human thumb is special ized to a high degree and freedom from use in locomotion permits the hands a great development of skill in many direc tions. In apes there are really four hands, but the pair with opposable first digit is situated on the portion of the body farthest fom tho head, so that neither pair is ad vantaged to specialize after the manner of ih? hand of man- This physical condition alone would prevent the ape from reach ing the same mental development as man. Tho foot portion of the posterior ex tremity of both ape and man represents in its fundamental plan the typical extromity o all vertebrates above the fish. It has the came elements arranged in the same order with relation to each other. It is charac terized, as in normal mammals and rep tiles, by five digits or fingers, In which tho inner or first digit corresponds to the thumb and is composed o a smaller num ber of phalanges or finger bones than tho other digits. In tho apes the first digit of tho foot is, as in normal mammals and reptiles, mucn shorter than the other, but is distinguished by extraordinary mobility, including oppo sabillty to the other digits, as- seon in the thumb of tho human hand. In tho foot of man, with the same funda mental plan seen in the apes, we find an extreme modification rarely seen In ints vertebrates in that theeiiormally short firsi digit, while retaining the normal number of joints for mammals, has been greatly enlarged and elongated until it equals or ex ceeds the longest of the other digits. This is what we call the big toe. The big toe has rel atively very small mo bility and is not i any sense opposable. The type of modification is "so extraordinary among the great number of foot forms known among different fami lies of animals that we must assume for it' an important relation to an extraordinary use. This we find, says Professor Merriam, in tho usual position of the fore and aft axis of the foot, which ruus obliquely across the foot and through the great toe, instead of through the middle toe, as In most animals, thus giving us a foot Why Four-Footed rAnimals Cannot WalU Erect. Interesting Drawing by Mr. Dan Beard, Showing the Relative Position of the Impor tant Joints of the Skeleton of a Man and a Horse. with the toes turned out, the weight of tho body being borne very largely upon the end of the big toe. This peculiar modification of tho human foot has been a most important part of the evolution of man into a long-logged, two footed creature running with outturned toes. The development of these rigid, the hands free to serve the head and of developing 'the head. Thus we owe our proud position as the powerful feet has had the effect ot leaving highest of thinking animals largely to our big toes. Thia difference between the human foot and the ape's foot is, in the Opinion ot present-day. scientists, the strongest evi dence of wide separation between man and the ape. The attractive chlmpauzoe can only be regarded as our distant cousin. Pro fessor Merriam considers that the separa tion is wide enough to Indicate that the beginning of changes leading toward tho (C) 1910, Internationa) Feature So-tIcc, Inc. human type of foot must have occurred at a very remote time, at least as early as the incipient specialization of the ape group. That specialization tended to produce a peculiar adaptation to tree lifo through use of the fore limbs for swinging or climb ing, with tho hind limbs used for grasping. There is another view, however, which has been taken by Dr. W. K. Gregory, that the human group may be derived from an ape lype which had gone far in the direc tion of tree dwelling and later loft the trees and passed through rapid evolution ary stages, producing a long-legged moving type with greatly developed big toe. According to Gregory, the erect position of man has been made possible by great elongation of arm, permitting fairly erect position of tho body in an ape-like ances tor who rested his weight in some part upon tho fore limbs in walking, as tho modern gorilla does. Great Britain Rlclits Reserved. Should the views expressed by Gregory prove correct, man might be derived with changes of relatively little significance from the most man-like of modern apes. If other views are correct, the gap is wider and the modern apes will be assumed to represent a type built especially for the trees, while man will bo considered a type practised in running, long accustomed with free hand to serve a brain given wider opportunity for range of thought. Professor Merriam makes the interest ing suggestion that the "missing links" in man's chain of evolution may be found in the lG.OOO-foot deep Slwalik beds in north ern India, which aro filled with uncount able fossils of oxtinct animals accumulated during hundreds of thousands of years, and which have as yet been bnrely touched by the hands ot scientists. That man's evolution has been deeply affected by his ancestors' lifo in trees is a t (A) The Footprint of a Child Be 1 fore It Has Been Deformed by; , jH Shoes and Showing the Power- i ful Big Toe and Wide Stretch of the Whole Five Toes. I, (B) Footprint of Gorilla's Foot, j' Showing the Four Fingerlikc Small Toes ind the Position of the First Toe, Which Is Really a Thumb. , . (C) Photograph of a ' tf'SBfr. Gorilla's Foot, Show- I WitiMrS in& How This Ani HPpfk mal's Big Toe Is Real- 1 Kf ly a Thumb -That Can I 1 yk? Be Turned Toward u SpjBlL&, tne Centre of the Foot , WllmW&' Photo by E. R. Sanborn imwKi' r-& for the New York Zoological ' F conclusion that has been ' j utft reached by many scien , , . K?!mOVtf tists. A most interesting ' SSWv theory in a book, "Arbore- f i f " al Man," by Professor F. IH -L Woow Jones, of the Uni- j 'IH vehsity of London. jjH me quadrupeds, Professor Wood Jone3 JM points out. are generally marked by rigid . . IH limbs only suited for backward and fdV - 1 ward movements. The head is connected , I jH with tho neck and shoulders in a manner f that makes easy rotation of the head ira ! possible. Man's anatomy is remarkable for its ' freedom from such restriction. This may , be explained by the fact that an early an cestor of man, a lemur-like animal, left !' the ground and took to tree life. By climbing with his forearms and hanging J i from branches his arms acquired their flexible -character and freedom of rotation at the shoulder. As ho hung from trees by the hands a 1 ' great deal, his hind limbs became straight and acquired freedom of rotation at tho ' ! , hips, which ordinary mammals do' not " ; I possess. When at rest in tho trees he sat on JM branches and revolved his head or lifted it up to look at his surroundings. ' Tho mere fact that this tvee-dwelllng creature could sit on a branch and turn his head around freely was of vital im- . portanco in stimulating brain development. The brain in such an anatomical position , could grow much larger than if it were 1 encased in a head fastened closely to the i shoulders by ligaments, as it is in the sur- t face quadrupeds. As the tree dweller sit- J ting among the branches turned his head around and then gazed upward at the sky I it is reasonable to bolievo that the first i rudiments of really human thought orlg- H inated in his brain. Tho high intelligence j'H of the birds may be traced to the same ' H freedom of the head articulation. i !H At a later stage food conditions led him t to descend to the ground, where he found ijH his upright hind limbs of great service in j running and walking. The freedom of : movement at the shoulders and hips gave 1 j him enormous advantages in a life of war- 1 , faro and thus he rapidly evolved into a j IH When pursued by a stronger enemy ' one, perhaps, who had caught him un- il armed tho primitive man could always ll turn his head while running and look at IJ his pursuer and decide what was best tG do. No quadruped possesses the same ad- . vantage and naturalists know that hunted animals often lose their lives through turn- j ing their .whole bodies to look at their pur- '1 suors. Man's hand then enabled him to 'H handlo and throw a weapon, which gave him his most decisive advantage over all other animals. But how are we related to the apes? Certain of the tree dwellers, according to i'I this theory, specialized very intensely in 'll tree climbing and thus developed hind ex- , il tremitics, which could only be used for -1 tree grasping. They could not live on jH tho ground conveniently, thus they do 1 jH celoped into apes, which are mainly tree- jH iwollers. t