(Based on Notes of a Series of Lectures on “The Sexes in Evolution.”)
In the present state of our knowledge of biological matters, no fact is more patent than that sex constitutes one of the greatest underlying principles throughout Nature.
Students of evolution will appreciate the fact that sex, like any other biological feature, has undergone a progressive evolutionary development—a development exhibiting many phases, both simple and complex—until we arrive at what is termed its “highest expression,” that of the human male and female.
Much of the course of this development is known, but the question of the origin of sex itself still remains one of the puzzling problems of biology. Certain it is that there was a time when what we know as “sex” did not exist. In many “lowly” organisms this condition of sexlessness obtains to-day. But at one stage in the development of living forms this condition was universal. By and bye there came a differentiation in the development of organisms, which resulted in a division of labour, where the special functions of each were confined to two separate and distinct individuals. From this point the independent history of the male and female sexes begins. Probably from the time of the appearance of life on the earth to that of the establishment of separate sexes, millions of years intervened. And probably, also, from the time that sex first made its appearance, millions more have elapsed. How and why sex differentiation came about at all is problematical. In all likelihood some crisis arose which threatened the existence of the particular species in which the phenomenon first occurred, and which had its appropriate physiological response in the organism, resulting in a division of labour, for, fundamentally, male and female are the same in biological essentials, the difference being some subtle biochemical quality whose essence is not quite understood.
We pass on, then, to the rise of the human animal where this sex differentiation concerns us most. They, like all other animals, have arisen from a line of organisms whose sex organs are ultimately identical, but in which, since modifications were introduced, have resulted in differences that are now of fundamental biological importance. Hence the “femininity” of women is not the product of education or convention, but is essentially biological in character. When our knowledge of the history of life on the earth has become more extended, it will be found that it is only by tracing the processes of differentiation throughout the two entire lines of development that we may hope to unravel all the mysteries bound up in the problem of sex, or to understand the prevailing differences in character and constitution which have arisen as the outcome of this early division of labour.
Tom Sala
1 comment:
Hat tip to ALB for originally scanning this in.
Mmm, not sure where this is going.
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