De muchas de sus ideas y consejos deberíamos tomar hoy buena nota.
Curiosamente comienza con una frase dirigida a quienes se muestran demasiado confiados en los avances notables en el estudio de la evolución así:
"Occasionally one hears today the statement that we have come to realize that we know nothing about evolution. This point of view is a healthy reaction to the over-confident belief that we knew everything about evolution.
Porque (P 26):
"My good friend the paleontologist is in greater danger than he realizes, when he leaves descriptions and attempts explanation. He has no way to check up his speculations and it is notorious that the human mind without control has a bad habit of wandering."
"The geneticist says to the paleontologist, since you do not know, and from the nature of your case can never know, whether your differences are due to one change or to a thousand, you can not with certainty tell us anything about the hereditary units which have made the process of evolution possible.
And without this knowledge there can be no understanding of the causes of evolution."
El genético dice al paleontólogo, ya que usted no sabe y por la naturaleza de su caso, nunca sabrá, si sus diferencias son debidas a un cambio o a mil, usted no puede decirnos ciertamente acerca de las unidades de la herencia que han hecho posible la evolución.
Y sin este conocimiento no pueden entenderse las causas de la evolución.
No obstante, también Morgan a veces se equivocaba. Veamos sino ( p 38)
"Today the belief that evolution takes place by means of natural processes is generally accepted. It does not seem probable that we shall ever again have to renew the old contest between evolution and special creation."
En general, su escrito es de una gran lucidez y acierto:
"We must find out what natural causes bring about variations in animals and plants; and we must also find out what kinds of variations are inherited, and how they are inherited. If the circumstantial evidence for organic evolution, furnished by comparative anatomy, embryology and paleontology is cogent, we should be able to observe evolution going on at the present time, i.e. we should be able to observe the occurrence of variations and their transmission. This has actually been done by the geneticist in the study of mutations and Mendelian heredity, as the succeeding lectures will show."