April 4, 2022 | Jerry Bergman

Sexual Selection Comes Under Fire

From several fronts, new problems confront
Darwin’s other selection theory


by Jerry Bergman, PhD

The idea of sexual selection was a concept developed by Darwin to explain the large number of traits that could not be explained by natural selection. The reason is that some of them decrease fitness. Examples include the clumsy antlers of deer, the many colorful differences in birds and certain animals which makes them more visible to predators, and even the sexual dimorphism existing in many animals.

Traditional Roles vs Sexual Selection

Before Darwin, the differences between the sexes were seen as examples of the beauty and design by the Creator. Human male and females were different because they were created for different roles in life: females to bear children and nurture them until they go off on their own and create their own families; males to support and protect their families. The differences were part of the design to carry out God’s reproductive purpose for them.

Creation Museum (AiG)

This Biblical idea was replaced in secular society by evolutionary philosophy and, as a result, “Darwin’s theory of sexual selection fundamentally changed how we think about sex and evolution.”[1] In short, sexual differences evolved like everything else. Darwinism postulated that there originally were no differences between the sexes aside from gonads, but male and female choice gradually evolved the many decorative differences that exist today. Women selected men that were tall, muscular, had facial hair, a deeper voice, and other traits. Men selected women who lacked facial and most other body hair, were less muscular than males, had a slender waist, wide hips, and large breasts (i.e., the stereotypical “hourglass” figure).

Problems with Sexual Selection Theory

If no sexual dimorphism existed at first, several theoretical questions arise. What traits at this time attracted the sexes to mate with the other sex and why? This would be a problem if the males and females of our alleged common ancestor looked identical. But if they were, they must have reproduced satisfactorily, because their descendants are around today. Would some early slight difference in hair, for example, be noticeable enough to trigger sexual selection? Sexual dimorphism is seen in many birds, but not in others. Darwinians allege that females are presumably attracted to males with bright colors, but in the early stages of plumage evolution, the differences would have been very slight, such as a male bluebird with a small amount of blue on its head or wings. Blue selection, they say, would increase until the males ended up with the bright male colors as seen today. Another question is, where did the genes or the drive come from that first caused female blue birds to prefer blue-feathered males? What about red cardinals? Why did one species of bird sexually select for blue, and another for red, yet another for yellow, and yet another for green or black or some dull color? This theory is far more like a just-so story than science. Sexual dimorphism is lacking in other bird species, such as crows and bald eagles.

The best-known case of sexual selection involves the peacock. This was the example Darwin himself used and it is still being used today. Unfortunately for the theory, research in 2008 found that the gaudy tail display in males is largely irrelevant in mating preference![2] The female peahens appear to pay little attention to the peacock’s tail. Most likely, many other sexual differences evolutionists allege to be important in sexual selection are probably irrelevant to the animals. Scientists still debate what factors are relevant.

In modern secular society sexual differences are deemed largely irrelevant

The secular trend today is to say that human sexual dimorphism is largely irrelevant. The minor plumbing differences, we are told, shouldn’t matter for educational and occupational success. Today, any remaining occupational differences between men and women is believed by secularists to be due to discrimination and societal bias. When I was teaching college, the government was cajoling us to have the same ratio, or close, of male to female students in nursing, elementary education, engineering, welding, and all other academic programs. To meet yearly goals, we were to eventually achieve equal enrollment of males and females in all academic areas.

Biological sex less important than what sex you think you are

Another fad is at work in society today. Many influencers allege that if your biological sex is incongruent with the gender you believe you are, your perceived gender should triumph. To make a person’s biology match one’s self-perceived gender as closely as possible, some doctors are using puberty-blocking hormones, lifelong hormone treatment, and surgery. Cases exist of males who married, had several children, and later in life decided they were actually females. To fix the “mistake” that occurred at conception, these transsexuals changed their dress and demanded they be referred to as females. And, if you use the term ‘male’ to refer to them, you will be banned from Twitter because using the wrong pronouns that a “non-binary” person prefers is now regarded as hate speech. One recent example involved Rachel Levine, Assistant Secretary of Health at the Department of Health and Human Services, who is now the highest-ranking openly transgender government official in U.S. history.

Doctors used to label such cases as gender dysphoria. A psychologist was required to diagnose the condition. These days, a self-diagnosis is considered the correct diagnosis, even if it is being made by one as young as twelve years old. Influencers in the transgender movement insist that those who make such self-diagnoses do indeed deserve to get surgery and hormone treatment. Male swimmers are now allowed to compete with women and those who object are being labeled transphobic. A recent example is the case of the Pennsylvania State University student Lia Thomas, who used to be a mediocre male swimmer named Will Thomas. After transitioning, “she” walked away with most of the world records for women swimmers. A report in The New Yorker wrote:

Her body, with its solid pectorals and compact, muscled hips, characteristic traits of a male athlete, didn’t align with her sense of who she was… men have testosterone levels around fifteen times that of women, and the competitive advantages of taking testosterone—at least exogenous testosterone, a steroid—were well established….  In the summer of 2018, after her freshman season, she realized that she was a woman, not a man…. hormone-replacement therapy may not counteract all the competitive advantages a body might gain during testosterone-driven puberty.[3]

Powerful forces in our culture insist that you are now the sex you say you are, not necessarily the sex you were born with. But there are an estimated 140 trillion cellular differences between males and females: the XY chromosomes are found in every male cell, and the XX chromosome pair is found in every female cell. Trans activists insist that Darwinism, Christianity and science need to be reinterpreted to accommodate their radical view of sexual differences.

Lia Thomas (left) formally Will Thomas, accepts the first-place trophy for the 500-yard freestyle finals as second-place finisher Emma Weyant and third-place finisher Erica Sullivan look on at the NCAA Swimming and Diving Championships on March 17 in Atlanta. Will Thomas is clearly a very large man, not a women by any standard.

The sexual selection idea is sexist

According to a new analysis published in Science by Rosenthal and Ryan on January 21, 2022, Darwin’s sexual selection theory had sexist roots and is being used to support sexism still today. The authors observed several problems with Darwin’s idea, such as the difficulty of defining specifically

what makes one prospective mate more enticing than another? Darwin, shaped by misogyny and sexual prudery, invoked a “taste for the beautiful” without speculating on the origin of the “taste.” How to explain when the “final marriage ceremony” is between two rams? What of … the sexual spectrum in humans, all observable in Darwin’s time? By explaining desire through the lens of those male traits that caught his eyes and those of his gender and culture, Darwin elided these data in his theory of sexual evolution.[4]

Another review of Darwin’s sexual selection theory by John Horgan in Scientific American in 2017 was more direct, asserting that “Darwin Was Sexist, and So Are Many Modern Scientists….”[5] The article correctly observed that when women were seeking the right to vote, it was eugenicist Francis Galton, evolutionist Charles Darwin, and other scientists who “hardened sexism into something that could not be challenged.”[6] Darwin’s writings on this subject are well known. One of many examples is found in his 1871 book The Descent of Man. Darwin wrote:

The chief distinction in the intellectual powers of the two sexes is [shown] by man attaining to a higher eminence, in whatever he takes up, than woman can attain–whether requiring deep thought, reason or imagination, or merely the use of the senses and hands…. Thus man has ultimately become superior to woman.[7]

Rosenthal and Ryan note a false assumption in sexual selection theory. They assert that

most attention has gone to the intuitive but tenuous premise that mating with gorgeous partners yields vigorous offspring…. By focusing on those aspects of mating preferences that coevolve with male traits, many of Darwin’s influential followers have followed the same narrow path.[8]

Furthermore, “Darwin’s misogyny precluded much analysis of the ‘taste’; an increasing focus on mate choice mechanisms but analysis of before, during, and after mating reveals that these often … have little to do with sexual selection on chosen traits.”[9] Other problems with the theory include the following:

Even as they evolve toward ever-more-beautiful signals and healthier offspring, mate-choice mechanisms and courter traits are locked in an arms race of coercion and resistance, persuasion and skepticism. Traits favored by sexual selection often do so at the expense of chooser fitness, creating sexual conflict. Choosers then evolve preferences in response to the costs imposed by courters.[10]


Sexual selection theory has come under fire because it was developed by Darwin, a man recognized today as both a sexist and racist. It also implies that the male-female differences are hardwired into people as a result of evolution. The new belief ignores both the science and Christianity, which together indicate that sexual differences are innate, science saying that the differences are genetic in nature, Christianity teaching that they were created in God’s original plan. Secular culture is teaching that they are learned or are due to cultural bias, and, thus, can be overcome. The latest fad is that one can be born into the wrong body. Can such a radical diagnosis be made by a single psychologist or, worse, by a pre-teen child? These notions are not only contrary to nature, but irresponsible, too.


[1] Rosenthal, G. and M. Ryan, Sexual selection and the ascent of women: Mate choice research since Darwin, SCIENCE  375(6578) DOI: 10.1126/science.abi6308, 21 January 2022.

[2] Takahashi, M., H. Arita, M. Hiraiwa-Hasegawa, and T. Hasegawa, Peahens do not prefer peacocks with more elaborate trains. Animal Behavior 75(4):1209–1219, doi: 10.1016/j.anbehav.2007.10.004, April 2008. See  also Petrie, M., Evolution by sexual selection. Frontiers in Ecology and Evolution 16 December 2021 | https://doi.org/10.3389/fevo.2021.786868.

[3] Thomas, L., The Trans Swimmer Who Won Too Much, The New Yorkerhttps://www.newyorker.com/sports/sporting-scene/how-one-swimmer-became-the-focus-of-a-debate-about-trans-athletes, 17 March 2022.

[4] Rosenthal and Ryan, 2022.

[5] Horgan, J., Darwin was sexist, and so are many modern scientists, Scientific American, https://blogs.scientificamerican.com/cross-check/darwin-was-sexist-and-so-are-many-modern-scientists/, 18 December 2017.

[6] Horgan, J., 2017.

[7] Darwin, C., The Descent of Man, London, UK: John Murray, 1871.

[8] Rosenthal and Ryan, 2022.

[9] Rosenthal and Ryan, 2022.

[10] Rosenthal and Ryan, 2022.

Lia Thomas (left) formally Will Thomas, accepts the first-place trophy for the 500-yard freestyle finals as second-place finisher Emma Weyant and third-place finisher Erica Sullivan look on at the NCAA Swimming and Diving Championships on March 17 in Atlanta. Will Thomas is clearly a very large man, not a women by any standard.

Dr. Jerry Bergman has taught biology, genetics, chemistry, biochemistry, anthropology, geology, and microbiology for over 40 years at several colleges and universities including Bowling Green State University, Medical College of Ohio where he was a research associate in experimental pathology, and The University of Toledo. He is a graduate of the Medical College of Ohio, Wayne State University in Detroit, the University of Toledo, and Bowling Green State University. He has over 1,300 publications in 12 languages and 40 books and monographs. His books and textbooks that include chapters that he authored are in over 1,500 college libraries in 27 countries. So far over 80,000 copies of the 40 books and monographs that he has authored or co-authored are in print. For more articles by Dr Bergman, see his Author Profile.

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