Tuesday, April 10, 2007
Homosexuality and Fraternal Birth Order
This is new story in the New York Times is really interesting:
Pas de Deux of Sexuality Is Written in the Genes
THE NEW YORK TIMES
By NICHOLAS WADE
Published: April 10, 2007
http://www.nytimes.com/2007/04/10/health/10gene.html?pagewanted=2&_r=1&th&emc=th
A somewhat more straightforward clue to the origin of homosexuality is the fraternal birth order effect. Two Canadian researchers, Ray Blanchard and Anthony F. Bogaert, have shown that having older brothers substantially increases the chances that a man will be gay. Older sisters don’t count, nor does it matter whether the brothers are in the house when the boy is reared.
The finding suggests that male homosexuality in these cases is caused by some event in the womb, such as “a maternal immune response to succeeding male pregnancies,” Dr. Bogaert wrote last year in the Proceedings of the National Academy of Sciences. Antimale antibodies could perhaps interfere with the usual masculinization of the brain that occurs before birth, though no such antibodies have yet been detected.
The fraternal birth order effect is quite substantial. Some 15 percent of gay men can attribute their homosexuality to it, based on the assumption that 1 percent to 4 percent of men are gay, and each additional older brother increases the odds of same-sex attraction by 33 percent.
The effect supports the idea that the levels of circulating testosterone before birth are critical in determining sexual orientation. But testosterone in the fetus cannot be measured, and as adults, gay and straight men have the same levels of the hormone, giving no clue to prenatal exposure. So the hypothesis, though plausible, has not been proved.
It may be interesting to look on the last-born sons in large families composed mostly of sons, to see what is their reproductive success. It should decrease as the number of older brothers increases, controlling for the sibship size. Any predictions about their health and longevity?
It may be interesting to test whether men with older brothers live shorter lives or not.
By the way, here is a link to original study:
- 1: Proc Natl Acad Sci U S A. 2006 Jul 11;103(28):10771-4. Epub 2006 Jun 28.
-
Biological versus nonbiological older brothers and men's sexual orientation.
Department of Community Health Sciences, Brock University, St. Catharines, ON, Canada. tbogaert@brocku.ca
The most consistent biodemographic correlate of sexual orientation in men is the number of older brothers (fraternal birth order). The mechanism underlying this effect remains unknown. In this article, I provide a direct test pitting prenatal against postnatal (e.g., social/rearing) mechanisms. Four samples of homosexual and heterosexual men (total n = 944), including one sample of men raised in nonbiological and blended families (e.g., raised with half- or step-siblings or as adoptees) were studied. Only biological older brothers, and not any other sibling characteristic, including nonbiological older brothers, predicted men's sexual orientation, regardless of the amount of time reared with these siblings. These results strongly suggest a prenatal origin to the fraternal birth-order effect.
PMID: 16807297 [PubMed - indexed for MEDLINE]
See also:
Conundrum: The Evolution of Homosexuality
by N. J. Peters, Authorhouse - February 28, 2006
The Puzzle: Exploring the Evolutionary Puzzle of Male Homosexuality
by Louis Arthur Berman, Godot Press, 2003
Monday, April 9, 2007
New Books
New Books on Aging and Longevity Studies.
You are most welcome to add new books here yourself if you do know some new interesting books!
Greetings,
This is a place for continuously updated list of new interesting books on aging and longevity.
Consider this as a starter, and please feel free to add new books here!
(Please do not forget to mention the book ISBN number, if you know it!)
New Books and Book Chapters:
• Ageing: The Paradox of Life
by Robin Holliday (Hardcover - Mar 2007)
• Ageing Well: Nutrition, Health, and Social Interventions
by Alan Dangour, Emily M. D. Grundy, and Astrid Fletcher - Mar 1, 2007
• Aging of the Genome: The Dual Role of DNA in Life and Death
by Jan Vijg
• Aging and Disability: Crossing Network Lines
by Michelle Putnam (Editor) - Feb 28, 2007
• The Art of Aging:
A Doctor's Prescription for Well-Being
by Sherwin B. Nuland - February 27, 2007
This popular book is discussed here.
• How to Live Forever or Die Trying
by Bryan Appleyard - January 22, 2007
This popular book discussed here
• Statistical and Process Models for Cognitive Neuroscience and Aging (Notre Dame Series on Quantitative Methodology)
by Michael J. Wenger and Christof Schuster (Editors) - Jan 15, 2007
• Aging Research: A Look at Some of the Scientific Evidence on Aging
by Harold Massie Ph.D. (Paperback - Jan 10, 2007)
• Health Aspects of Aging: The Experience of Growing Old
by Gari Lesnoff-Caravaglia (Hardcover - Jan 2007)
• Mechanisms of Dietary Restriction in Aging and Disease (Interdisciplinary Topics in Gerontology)
by C. V. Mobbs, K. Yen, and P. R. Hof
• Book Chapter "Cytokine Polymorphisms and Longevity"
By Irene Maeve Rea, Giuseppina Candore, Luca Cavallone, Fabiola Olivieri, Maurizio Cardelli, Claudio Franceschi, Giuseppina Colonna-Romano,Domenico Lio, Owen A. Ross and Calogero Caruso
In: Cytokine Gene Polymorphisms in Multifactorial Conditions
by Koen Vandenbroeck (Editor)
• Book chapter "Anti-Aging Medicine and Science: Social Implications" by Robert H. Binstock, Jennifer R. Fishman, and Thomas E. Johnson
In: Handbook of Aging and the Social Sciences, Sixth Edition (Handbook of Aging)
• Book chapter "Mechanisms of Aging"
by Leng SX and Fedarko NS.
In: Geriatric Anesthesia
by Frederick E. Sieber
• Human Longevity, Individual Life Duration, and the Growth of the Oldest-Old Population (International Studies in Population)
by Jean-Marie Robine (Editor), Eileen M. Crimmins (Editor), Shiro Horiuchi (Editor), Yi Zeng (Editor)
Note a chapter "Patterns in mammalian aging: demography and evolution" by SN Austad there.
• Book chapter "The Mouse in Aging Research"
by Flurkey K, Currer JM, Harrison DE.
In: The Mouse in Biomedical Research, Volume 1-4, Second Edition (American College of Laboratory Animal Medicine)
by James G. Fox, Stephen Barthold, Muriel Davisson, and Christian E. Newcomer
• Longevity Health Sciences: The Phoenix Conference (Annals of the New York Academy of Sciences)
by Richard G. Cutler, Stromboli Conference on Aging And Cancer, Walter Pierpaoli, and Phonenix Conference on Longevity Health
• Longer Life and Healthy Aging (International Studies in Population) 
Note a chapter there: "Aging without dementia"
by Barberger-Gateau P, et al.,
• Biological Aging:
Methods And Protocols
(Methods in Molecular Biology (Clifton, N.J.), V. 371.)
• Aging Nation:
The Economics and Politics of Growing Older in America
by James H. Schulz, Robert H. Binstock
• New Dynamics in Old Age:
Individual, Environmental And Societal Perspectives
(Society and Aging Series)
by Hans-Werner, Ph.D. Wahl (Editor), Clemens Tesch-roemer (Editor), Andreas Hoff (Editor)
• The Evolution of Death:
Why We Are Living Longer
(Suny Series in Philosophy and Biology)
by Stanley Shostak
• Biology, Sociology, Geology by Computational Physicists,
Volume 1 (Monograph Series on Nonlinear Science and Complexity)
by Dietrich Stauffer et al.
This book includes discussion of biological aging, human mortality and longevity.
• Extending the Lifespan:
Biotechnical, Gerontological, and Social Problems
by Klaus Sames (Editor), Sebastian Sethe (Editor), Alexandra Stolzing (Editor)
Contributions by:
Vladimir N. ANISIMOV, Alexander BUERKLE, Gerald DeHAAN, Gerhard HOFECKER, Michael S. JAZWINSKI, Frieder KELLER, Valery N. KHABASHESKU, Tilmann KLEINE, Rosemarie MARTIN, Christoph MEISSNER, Ann-Kathrin MEYER, Will W.MINUTH, Gerald M NCH, Khachik MURADIAN, William O. OGLE, Klaus P SCHEL, Wolfgang von RENTELN-KRUSE, Volker RICHTER, Ramon RISCO, George S.ROTH, Antonio RUIZ-TORRES, Kenneth B. STOREY, Stefan THALHAMMER, Peter VISCHER, Jan WOJNAR, Bartosz WOZNIAK
• Biology of Aging: Observations and Principles
by Robert Arking
Textbook, third edition
• Aging: Concepts and Controversies
by Harry R. Moody
• Enduring Questions in Gerontology
by Debra J. Sheets, Dana Burr Bradley, and Jon Hendricks
Note a chapter "A biologist’s perspective: whence come we, where are we, whither go we?" by SN Austad there.
• The Evolution of Aging
How New Theories Will Change the Future of Medicine
This popular book is discussed here
• The Truth About Aging: Can We Really Live Longer and Healthier? (Full Spectrum Information Library Series)
by George Roth
• What Books People Read?
Somewhat disturbing list of best-selling books on aging and longevity
Upcoming:
• Austad, SN & Finch, CE (2007) The evolutionary context of human aging and degenerative disease. in S.C. Stearns & J.C. Koella (Eds). Evolution in Health and Disease, 2nd Edition. Oxford University Press, Oxford, UK (in press).
• The Biology of Human Longevity:
Inflammation, Nutrition, and Aging in the Evolution of Lifespans
by Caleb E. Finch (Hardcover - Jun 26, 2007)
• Forever and Ever
by Dan A. Baker - April 1, 2007
This novel (not scientific book) is discussed here
Have Questions? Comments? New Books to Suggest?
Post them below!
Key words:
New books, Ageing, Aging, Longevity, Life-extension, Genome, DNA, Death, Disability, Growing Old, Dietary Restriction, Disease, Gerontology, Anti-Aging Medicine, Life Duration, Oldest-Old, Longer Life, Healthy Aging, Growing Older, Old Age, Evolution of Death, Lifespan, Evolution of Aging, Human Longevity.
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