National Academies Press: OpenBook

In the Light of Evolution: Volume III: Two Centuries of Darwin (2009)

Chapter: Part III: SEXUAL SELECTION, OR ADAPTATION TO MATING DEMANDS

« Previous: 8 In the Light of Directed Evolution: Pathways of Adaptive Protein Evolution--Jesse D. Bloom and Frances H. Arnold
Suggested Citation:"Part III: SEXUAL SELECTION, OR ADAPTATION TO MATING DEMANDS." National Academy of Sciences. 2009. In the Light of Evolution: Volume III: Two Centuries of Darwin. Washington, DC: The National Academies Press. doi: 10.17226/12692.
×

Part III
SEXUAL SELECTION, OR ADAPTATION TO MATING DEMANDS

In The Descent of Man, and Selection in Relation to Sex, Darwin defined sexual selection as the “advantage which certain individuals have over other individuals of the same sex and species, in exclusive relation to reproduction.” Darwin appreciated that sexual selection could be mediated by intrasexual combat (e.g., between males) or by intersexual preferences (e.g., female choice of attractive mates). He also appreciated that sexual selection could be in opposition to natural selection with respect to particular phenotypic traits (such as a peacock’s tail), but he generally viewed sexual selection as less effective than natural selection.

After discussing Darwin’s original ideas about sexual selection (especially as presented in The Descent of Man), Adam Jones and Nicholas Ratterman in Chapter 9 identify three modern triumphs in sexual selection research: the introduction and widespread use of molecular markers to assess genetic parentage (the key to describing mating systems in nature) unequivocally; a better conceptual understanding (at least in formal models) of the mechanisms and consequences of mate choice by females (or by males in role-reversed taxa); and a better appreciation of why differences exist among lineages in the intensity of various forms of sexual selection. For the latter two topics, the histories of ideas on sexual selection—beginning with Darwin—are interwoven with how those notions laid the foundation for categorizing various forms of sexual selection, and for extending and expanding modern research into various aspects of sexual selection both in theory and empirically. The authors close by suggesting several lines of future research on sexual selection.

Suggested Citation:"Part III: SEXUAL SELECTION, OR ADAPTATION TO MATING DEMANDS." National Academy of Sciences. 2009. In the Light of Evolution: Volume III: Two Centuries of Darwin. Washington, DC: The National Academies Press. doi: 10.17226/12692.
×

In Chapter 10, Stephen Shuster provides a comprehensive overview (and contrast) of how sexual selection has been measured and studied in plant systems versus animal systems. One general theme that he emphasizes is the need to reconcile Darwin’s idea that sexual selection tends to be less rigorous than natural selection with the observation that sexual selection would seem to be responsible for many if not most differences between the two genders (in features other than the primary sex organs). In The Origin, Darwin wrote that sexual selection “depends, not on the struggle for existence, but on a struggle between males for possession of the females; the result is not death of the unsuccessful competitor, but few or no offspring. Sexual selection is, therefore, less rigorous than natural selection.” Shuster, by contrast, views sexual selection as being “among the most powerful of evolutionary forces.” The author proposes to reconcile these two stances in evolutionary models that combine quantitative differences in the fitness variances between the sexes (an approach traditionally applied to animal systems) with phenotypic and genotypic correlations underlying reproductive traits among breeding pairs (an approach often taken in plant systems). The net result, he claims, will be the ability to predict the magnitudes of sexual dimorphism and classify mating systems using existing genetic and life history data.

In Chapter 11, Patricia Gowaty and Stephen Hubbell offer a novel perspective on what underlies the individual decision-making process that in turn underlies patterns of mate choice and sexual selection in various species. Their central thesis is that even stochastic variation in various parameters that predict the time available for mating might promote considerable flexibility in individual decision making with regard to mate choice; and that even consistent sex differences in these mating proclivities might therefore, in at least some cases, reflect ecological constraints (habits-of-life considerations) rather than behavioral differences that might otherwise be genetically hardwired between the sexes. The parameters that might impact available time for mating include the probabilities of encountering mates, individual survivorships, mating latencies (times-out between mating events), and fitness distributions, all of which are likely to vary as functions of the natural histories as well as the evolutionary histories of species. Such considerations lead the authors to their switch point theorem, which in principle can quantitatively evaluate what proportion of potential mates in a population a focal individual should find acceptable as mating partners if it is to maximize its relative lifetime fitness.

In an uncharacteristic conceptual lapse, Darwin failed to appreciate that sexual selection (including both male-male competition and female choice) can continue even after copulation has begun. The intrasexual (male-male) component can happen via sperm competition for the fertilization of ova, and the intersexual component can occur via cryptic female

Suggested Citation:"Part III: SEXUAL SELECTION, OR ADAPTATION TO MATING DEMANDS." National Academy of Sciences. 2009. In the Light of Evolution: Volume III: Two Centuries of Darwin. Washington, DC: The National Academies Press. doi: 10.17226/12692.
×

choice of alternative sperm, all within the female’s reproductive tract. William Eberhard reviews the history of ideas for these underappreciated but nevertheless intense forms of postcopulatory sexual selection in Chapter 12. The miniature worlds of gametic competition and gametic choice have proven to be every bit as fascinating and compelling as the macroscopic worlds of mating competition and mate choice that have been the traditional foci of sexual selection studies. Eberhard brings this miniature Kama Sutra realm to light by detailing fascinating examples of sexual selection in the time interval (which is often but not invariably brief) between the onset of copulation and the completion of fertilization.

Suggested Citation:"Part III: SEXUAL SELECTION, OR ADAPTATION TO MATING DEMANDS." National Academy of Sciences. 2009. In the Light of Evolution: Volume III: Two Centuries of Darwin. Washington, DC: The National Academies Press. doi: 10.17226/12692.
×

This page intentionally left blank.

Suggested Citation:"Part III: SEXUAL SELECTION, OR ADAPTATION TO MATING DEMANDS." National Academy of Sciences. 2009. In the Light of Evolution: Volume III: Two Centuries of Darwin. Washington, DC: The National Academies Press. doi: 10.17226/12692.
×
Page 165
Suggested Citation:"Part III: SEXUAL SELECTION, OR ADAPTATION TO MATING DEMANDS." National Academy of Sciences. 2009. In the Light of Evolution: Volume III: Two Centuries of Darwin. Washington, DC: The National Academies Press. doi: 10.17226/12692.
×
Page 166
Suggested Citation:"Part III: SEXUAL SELECTION, OR ADAPTATION TO MATING DEMANDS." National Academy of Sciences. 2009. In the Light of Evolution: Volume III: Two Centuries of Darwin. Washington, DC: The National Academies Press. doi: 10.17226/12692.
×
Page 167
Suggested Citation:"Part III: SEXUAL SELECTION, OR ADAPTATION TO MATING DEMANDS." National Academy of Sciences. 2009. In the Light of Evolution: Volume III: Two Centuries of Darwin. Washington, DC: The National Academies Press. doi: 10.17226/12692.
×
Page 168
Next: 9 Mate Choice and Sexual Selection: What Have We Learned Since Darwin?--Adam G. Jones and Nicholas L. Ratterman »
In the Light of Evolution: Volume III: Two Centuries of Darwin Get This Book
×
Buy Hardback | $80.00 Buy Ebook | $64.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

Two Centuries of Darwin is the outgrowth of an Arthur M. Sackler Colloquium, sponsored by the National Academy of Sciences on January 16-17, 2009. In the chapters of this book, leading evolutionary biologists and science historians reflect on and commemorate the Darwinian Revolution. They canvass modern research approaches and current scientific thought on each of the three main categories of selection (natural, artificial, and sexual) that Darwin addressed during his career. Although Darwin's legacy is associated primarily with the illumination of natural selection in The Origin, he also contemplated and wrote extensively about what we now term artificial selection and sexual selection. In a concluding section of this book, several science historians comment on Darwin's seminal contributions.

Two Centuries of Darwin is the third book of the In the Light of Evolution series. Each installment in the series explores evolutionary perspectives on a particular biological topic that is scientifically intriguing but also has special relevance to contemporary societal issues or challenges. The ILE series aims to interpret phenomena in various areas of biology through the lens of evolution and address some of the most intellectually engaging, as well as pragmatically important societal issues of our times.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    Switch between the Original Pages, where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

    « Back Next »
  6. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  7. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  8. ×

    View our suggested citation for this chapter.

    « Back Next »
  9. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!