20 READINGS IN BIOLOGICAL SCIENCE 



THE EVIDENCE OF THE DESCENT OF MAN FROM 

 SOME LOWER FORM * 



CHARLES DARWIN 



He who wishes to decide whether man is the modified descendant of 

 some pre-existing form, would probably first enquire whether man varies, 

 however slightly, in bodily structure and in mental faculties; and if so, 

 whether the variations are transmitted to his offspring in accordance with 

 the laws which prevail with the lower animals. Again, are the variations 

 the result, as far as our ignorance permits us to judge, of the same general 

 causes, and are they governed by the same general laws, as in the case of 

 other organisms; for instance, by correlation, the inherited effects of use 

 and disuse, etc? Is man subject to similar malconformations, the result of 

 arrested development, of reduplication of parts, &c., and does he display in 

 any of his anomalies reversion to some former and ancient type of struc- 

 ture? It might also naturally be enquired whether man, like so many other 

 animals, has given rise to varieties and sub-races, differing but sHghtly from 

 each other, or to races differing so much that they must be classed as doubt- 

 ful species? How are such races distributed over the world; and how, 

 when crossed, do they react on each other in the first and succeeding 

 generations? And so with many other points. 



The enquirer would next come to the important point whether man tends 

 to increase at so rapid a rate, as to lead to occasional severe struggles for 

 existence; and consequently to beneficial variations, whether in body or 

 mind, being preserved, and injurious ones ehminated. Do the races or 

 species of men, whichever term may be applied, encroach on and replace 

 one another, so that some finally become extinct? We shall see that all 

 these questions, as indeed is obvious in respect to most of them, must be 

 answered in the affirmative, in the same manner as with the lower animals. 

 But the several considerations just referred to may be conveniently de- 

 ferred for a time: and we will first see how far the bodily structure of 

 man shows traces, more or less plain, of his descent from some lower 

 form. 



THE BODILY STRUCTURE OF MAN 



It is notorious that man is constructed on the same general type or model 

 as other mammals. All the bones in his skeleton can be compared with cor- 

 responding bones in a monkey, bat, or seal. So it is with his muscles, nerves, 

 blood-vessels and internal viscera. The brain, the most important of all the 

 organs, follows the same law, as shewn by Huxley and other anatomists. 

 Bischoff, who is a hostile witness, admits that every chief fissure and fold 



• From The Descent of Man and Selection in Relation to Sex by Charles Darwin. 

 D. Appleton and Co., New York. 1886. 



