Share

Human Sperm Competition

1994-12-31 Science
Download Human Sperm Competition PDF Online Free

Author :
Release : 1994-12-31
Genre : Science
Kind : eBook
Book Rating : 300/5 ( reviews)

GET EBOOK


Book Synopsis Human Sperm Competition by : R.R. Baker

Download or read book Human Sperm Competition written by R.R. Baker. This book was released on 1994-12-31. Available in PDF, EPUB and Kindle. Book excerpt: Behavioural ecologists and evolutionary biologists have long been interested in the biological implications of sperm from different males competing for fertilization of the egg in the female tract. This book discusses these implications for human sexual behaviour and human infertility problems.

Sperm Competition in Humans

2010-10-29 Science
Download Sperm Competition in Humans PDF Online Free

Author :
Release : 2010-10-29
Genre : Science
Kind : eBook
Book Rating : 173/5 ( reviews)

GET EBOOK


Book Synopsis Sperm Competition in Humans by : Todd K. Shackelford

Download or read book Sperm Competition in Humans written by Todd K. Shackelford. This book was released on 2010-10-29. Available in PDF, EPUB and Kindle. Book excerpt: In species with internal fertilization, sperm competition occurs when the sperm of two or more males simultaneously occupy the reproductive tract of a female and compete to fertilize an egg (Parker, 1970). A large body of empirical research has demonstrated that, as predicted by sperm competition theory, males and females in many species possess anatomical, behavioral, and physiological adaptations that have evolved to deal with the adaptive challenges associated with sperm competition. Moreover, in recent years, evolutionary biologists and psychologists have begun to examine the extent to which sperm competition may have been an important selective pressure during human evolution. Some research has suggested that male humans, like males of many bird, insect, and rodent species, might be able to adjust the number of sperm they inseminate according to the risk of sperm competition. Other research has examined whether such responses might be accompanied by psychological changes that motivate human males to pursue copulations when the risk of sperm competition is high. Furthermore, there is research suggesting that aspects of human penile anatomy might function to enhance success in sperm competition. Much of this work has been controversial; some of the findings have been disputed and others have been greeted with skepticism. However, the idea that some aspects of human psychology and behavior might best be understood as adaptations to sperm competition remains intriguing and, in certain cases, very persuasive.

Sperm Competition in Humans

2006-11-22 Science
Download Sperm Competition in Humans PDF Online Free

Author :
Release : 2006-11-22
Genre : Science
Kind : eBook
Book Rating : 391/5 ( reviews)

GET EBOOK


Book Synopsis Sperm Competition in Humans by : Todd K. Shackelford

Download or read book Sperm Competition in Humans written by Todd K. Shackelford. This book was released on 2006-11-22. Available in PDF, EPUB and Kindle. Book excerpt: In species with internal fertilization, sperm competition occurs when the sperm of two or more males simultaneously occupy the reproductive tract of a female and compete to fertilize an egg (Parker, 1970). A large body of empirical research has demonstrated that, as predicted by sperm competition theory, males and females in many species possess anatomical, behavioral, and physiological adaptations that have evolved to deal with the adaptive challenges associated with sperm competition. Moreover, in recent years, evolutionary biologists and psychologists have begun to examine the extent to which sperm competition may have been an important selective pressure during human evolution. Some research has suggested that male humans, like males of many bird, insect, and rodent species, might be able to adjust the number of sperm they inseminate according to the risk of sperm competition. Other research has examined whether such responses might be accompanied by psychological changes that motivate human males to pursue copulations when the risk of sperm competition is high. Furthermore, there is research suggesting that aspects of human penile anatomy might function to enhance success in sperm competition. Much of this work has been controversial; some of the findings have been disputed and others have been greeted with skepticism. However, the idea that some aspects of human psychology and behavior might best be understood as adaptations to sperm competition remains intriguing and, in certain cases, very persuasive.

Sperm Wars

2006-01-03 Psychology
Download Sperm Wars PDF Online Free

Author :
Release : 2006-01-03
Genre : Psychology
Kind : eBook
Book Rating : 965/5 ( reviews)

GET EBOOK


Book Synopsis Sperm Wars by : Robin Baker

Download or read book Sperm Wars written by Robin Baker. This book was released on 2006-01-03. Available in PDF, EPUB and Kindle. Book excerpt: This classic work on the rules of sex -- updated for a new generation -- is still as provocative as the day it was published, providing simple explanations for any and all questions about what happens in the bedroom. Sex isn't as complicated as we make it. In Sperm Wars, evolutionary biologist Robin Baker argues that every question about human sexuality can be explained by one simple thing: sperm warfare. In the interest of promoting competition between sperm to fertilize the same egg, evolution has built men to conquer and monopolize women while women are built to seek the best genetic input on offer from potential sexual partners. Baker reveals, through a series of provocative fictional scene, the far-reaching implications of sperm competition. 10% of children are not fathered by their "fathers;" over 99% of a man's sperm exists simply to fight off all other men's sperm; and a woman is far more likely to conceive through a casual fling than through sex with her regular partner. From infidelity, to homosexuality, to the female orgasm, Sperm Wars turns on every light in the bedroom. Now with new material reflecting the latest research on sperm warfare, this milestone of popular science will still surprise, entertain, and even shock.

Sperm Competition and the Evolution of Animal Mating systems

2012-12-02 Science
Download Sperm Competition and the Evolution of Animal Mating systems PDF Online Free

Author :
Release : 2012-12-02
Genre : Science
Kind : eBook
Book Rating : 13X/5 ( reviews)

GET EBOOK


Book Synopsis Sperm Competition and the Evolution of Animal Mating systems by : Robert L. Smith

Download or read book Sperm Competition and the Evolution of Animal Mating systems written by Robert L. Smith. This book was released on 2012-12-02. Available in PDF, EPUB and Kindle. Book excerpt: Sperm Competition and the Evolution of Animal Mating Systems describes the role of sperm competition in selection on a range of attributes from gamete morphology to species mating systems. This book is organized into 19 chapters and begins with the conceptualization of sperm competition as a subset of sexual selection and its implications for the insects. The following chapter describes the relationship between multiple mating and female fitness, with an emphasis on determining the conditions under which selection on females is likely to counteract selection on males for avoiding sperm competition. Other chapters consider the female perspective on sperm competition; the evolutionary causation at the level of the individual male gamete; and the correlation of high paternal investment and sperm precedence in the insects. The remaining chapters are arranged phylogenetically and explore the sperm competition in diverse animal taxa, such as the Drosophila, Lepidoptera, spiders, amphibians, and reptiles. These chapters also cover the evolution of direct versus indirect sperm transfer among the arachnids or the problem for kinship theory presented by multiple mating and sperm competition in the Hymenoptera. This book further discusses the remarkable potential for sperm competition among certain temperate bat species whose females store sperm through winter hibernation and the mixed strategies and male-caused female genital trauma as possible sperm competition adaptations in poeciliid fishes. The concluding chapter examines the predictions concerning testes size and mating systems in the primates and the possible role of sperm competition in human selection. This book is of great value to reproductive biologists and researchers.

You may also like...