New book demystifies human sex via highly memorable non-human comparisons
It’s a challenge to write something original on a topic that’s as old as time, but the subject of sex is arguably never boring. Facuty of Science Professor Alexander Mills, associate dean, students, proves this point in spades. He has written an engaging and intellectually challenging new textbook, Biology of Sex, published by the University of Toronto Press (2018).
In this new book, Mills approaches the topic of sex and reproduction in a wholly original way by presenting intriguing comparisons between human sex and the many variations in sexual systems among non-human organisms. “By comparing the characteristics and patterns of a diversity of species, our knowledge of all life, including humans, is enriched,” he explains.
It’s not for the faint of heart. The author describes quite a few non-human species that maim, coerce, kill and eat their partners during the mating process, for example. Indeed, this publication is chock-a-block with highly memorable biological truths.
In writing this book, Mills sought to demystify so-called black box topics – voids in most people’s understanding of sex and the “facts of life.” This publication reflects Mills’ keen interest in aiding scientific literacy and, more specifically, improving the methods of teaching post-secondary biology.
Comprehensive book covers vast territory
Mills tackles this very large topic systematically over 400+ pages, considering genetic, physiological and evolutionary principles. He opens with sexual reproduction; asexual reproduction, as in the case of bacteria; and non-sexual reproduction in unicellular and multicellular organisms. He then moves on to sex and inheritance, which profiles DNA and chromosomes.
Chapter 4, on sex and evolution, is very interesting as it discusses the principles of natural selection and the role of sex in the creation of species. Chapter 5 continues the discussion on sexual selection, a subcategory of natural selection.
The book also profiles mating systems by breaking the topic down into monogamy and several types of polygamy, including polyandry, a form of polygamy where a female takes two or more male partners at a time. Mills also covers homosexuality. He states that homosexuality and associated behaviours, including same-sex courtships and pair-bonding behaviours, exist in hundreds of species, including mammals, birds, reptiles and insects. The biology of sexual conflict – before, during and after mating, and during parenting – is also covered.
Some content will be controversial
The book tackles many timely issues, some of which will be controversial.
Assigned sex, transgender and gender dysphoria, which occurs when sex assignment based on genital inspection does not align with the individual’s developing identity, are discussed. Mills explains that in the natural world there are individuals who are not clearly male or female, and many organisms are gender neutral. “However, the binary, male-female model runs very deep in biology,” he writes.
In Part 8, the author notes that environmental sex determination can override genetic sex determination in nature – as is the case for many developing reptiles. He also considers cases where mothers can use temperature to select their offspring’s sex and reflects on social systems of sex determination. Sex allocation is adaptive when having offspring of a particular sex is advantageous, he reports.
Mills also considers anomalies in sex chromosomes, genetic mutations, intersex conditions and rare cases where children who appear to be girls develop into men at puberty.
Read more in yFile.
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