In Part 1 of the “Evolution of Sex,” I described a few of the major problems facing boys and men said that what boys and men need more than anything else is to reconnect with the community of life on planet Earth. The admonition to “know thyself” is a philosophical Delphic-maxim which was inscribed upon the Temple of Apollo in the ancient Greek precinct of Delphi. Understanding the biological roots of maleness is a key to knowing the essence of who we are as males and being guided by that wisdom.
To make sense of our biology, we have to understand something about how life evolves. Theodosius Dobzhansky was a prominent Ukrainian-American geneticist and evolutionary biologist, and a central figure in the field of evolutionary biology for his work in shaping the modern synthesis.
He said, “Nothing in biology makes sense except in the light of evolution.”
In their book, Gender Gap: The Biology of Male-Female Differences, evolutionary psychologist David P. Barash, PhD. and his wife, Judith Eve Lipton, MD, who is a medical doctor and psychiatrist say,
“When it comes to human nature, the differences between males and females must be acknowledged as real, important, and downright fascinating. Moreover, when it comes to understanding those differences, there is no better guide than evolution.”
Understanding the biological and evolutionary basis of our maleness in no way discounts the fact that there are also psychological, social, and cultural differences that are important as well. Nature and nurture can never be separated. They are now, and forever, united.
Let me be clear. What I will share about males and females are generalizations. A generalization, by definition, applies to the majority within a population, allowing plenty of room for individual exceptions. If I told you that men are taller than women, you would recognize that this is not true of all men. As a 5’5’’ guy, I’m very aware that this is a generalization — though I still wish I could magically become an undersized 6’5” basketball forward.
Yet, the generalizations can tell us a lot about who we are and why we evolved the thoughts, feelings, and behaviors that make us who we are. Because men tend to be a certain way does not mean that men are better than women or that these qualities are fixed and can’t change.
Biologists have a very simple and useful definition of what is male and what is female, whether we are fish, ferns, or human beings. An individual can either make many small gametes (sex cells) or fewer but larger gametes. The individuals that produce smaller gametes are called “males” and the ones that produce larger gametes are called “females.”
Since it makes biological sense to have the smaller male cells to move toward the larger female cells, it is usually the male that seeks out the female and the female who chooses which males she will allow to mate with her.
In the past, it was assumed that the egg was passive, just waiting for the male sperm to penetrate her membrane. More recent studies have demonstrated that the egg is far from being a passive recipience, but actually “chooses” which sperm to allow entrance.
In Part 1, I described the work of cosmologist Dr. Brian Swimme and historian Thomas Berry. In their book, The Universe Story, they described the first male organism, they call him Tristan, and the first female organism, they call her Iseult, and their coming together in the ancient oceans of planet Earth. This billion-year-old story takes us back to the emergence of the first sperm, the beginning of maleness, and our first male ancestor.
This is the first love story and the beginning act to a play that continues to unfold today. But as evolution continued, and the first multicellular animals appeared 700 million years ago, we started on the long journey to becoming the unique men we are today.
In the world of biology, size and numbers matter. Most of us are not aware of the difference in size and number between a sperm and an egg. A human egg is 85,000 times larger than a sperm. Each man produces 100 to 300 million sperm per ejaculate and must compete for access to that one precious egg produced by the female. Over a woman’s lifetime, approximately 400 to 500 eggs are released during ovulation.
Dr. Stephen Emlen is Professor of Behavioral Ecology at Cornell University and a world authority on the social behavior of animals. He says,
“Because of all the resources a female will put into each egg, it makes sense, in most cases, for her to be choosy about whose genes she allows to combine with it, and to continue to invest in its growth and survival after fertilization. For the male, it usually pays best to compete with other males for access to as many eggs as possible. This tends to give rise to the more traditional male/female sex roles.”
Our different genetic heritage also helps us better understand the biology of maleness. David C. Page, M.D., is professor of biology at the Massachusetts Institute of Technology (MIT) and director of the Whitehead Institute, where he has a laboratory devoted to the study of the Y-chromosome. He says,
“There are 10 trillion cells in the human body and every one of them is sex specific.”
He goes on to say, “It has been said that our genomes are 99.9% identical from one person to the next. It turns out that this assertion is correct as long as the two individuals being compared are both men. It’s also correct if the two individuals being compared are both women, but the genetic difference between a man and a woman are 15 times greater than the genetic difference between two men or between two women.”
Dr. Page concludes by saying, “We’ve had a unisex vision of the human genome, but men and women are not equal in our genome and men and women are not equal in the face of disease. We need a tool kit that recognizes the fundamental difference on a cellular, organ, system, and person level between XY and XX. I believe that if we do this, we will arrive at a fundamentally new paradigm for understanding and treating human disease.”
In the past, some believed that when we acknowledged biological differences between males and females, it would encourage the belief that women were inferior to men and their biology precluded them from being in positions of power. However, more recent research has demonstrated that our biology does not have to preclude men and women from entering certain professions or being capable of exercising leadership. It does not demonstrate male superiority, but, actually, the opposite.
Melvin Konner, M.D. is one of the most respected experts in the field of Gender-Specific Health. In his book, Women After All: Sex, Evolution, and the End of Male Supremacy, he says,
“Women are not equal to men; they are superior in many ways, in most ways that will count in the future. It is not just a matter of culture or upbringing, although both play their roles. It is a matter of biology and of the domains of our thoughts and feelings influenced by biology. It is because of chromosomes, genes, hormone, and nerve circuits. It is not mainly because of what your mother taught you or how experience shaped you. It is mainly because of intrinsic differences in the body and the brain.”
We will explore more about the evolution of sex and the biological differences between males and females in future articles. If you have not already subscribed to my free weekly newsletter, I invite you to subscribe here.