Interactive video lesson plan for: Why Do We Have More Boys Than Girls?

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Created by Henry Reich
Production and Writing Team: Alex Reich, Peter Reich, Emily Elert, Ever Salazar, Kate Yoshida, and Henry Reich
Music by Nathaniel Schroeder: http://www.soundcloud.com/drschroeder
Narrated by: Emily Elert
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MinuteEarth provides an energetic and entertaining view of trends in earth's environment -- in just a few minutes!

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References

Cameron, E.Z. (2004). Facultative adjustment of mammalian sex ratios in support of the Trivers-Willard hypothesis: evidence for a mechanism. Proceedings of the Royal Society of London Series B 271:1723–1728. http://rspb.royalsocietypublishing.org/content/271/1549/1723

Chahnazarian, A. (1988). Determinants of the sex ratio at birth: Review of recent literature. Social Biology 35 (3–4): 214–235. http://www.tandfonline.com/doi/abs/10.1080/19485565.1988.9988703?journalCode=hsbi20#.U-5oSPldWRM

Coale, A.J. (1991). Excess female mortality and the balance of the sexes in the population: An estimate of the number of "missing females." Population and Development Review 17(3): 517-523.http://www.jstor.org/discover/10.2307/1971953?uid=3739824&uid=2&uid=4&uid=3739256&sid=21104121507601

Clutton-Brock, T. H., Albon, S. D., and Guinness, F. E. (1986). Great expectations: dominance, breeding success and offspring sex ratios in red deer. Animal Behavior 34: 460-471. http://www.kora.ch/malme/05_library/5_1_publications/C/Clutton-Brock_et_al_1986_Dominance_breeding_success_and_offspring_sex_ratios_in_red_deer.pdf

Kalben B. (2000). Why men die younger: causes of mortality differences by sex. North American Actuarial Journal 4(4): 83–111. https://www.soa.org/news-and-publications/publications/other-publications/monographs/m-li01-1-toc.aspx

Schnettler, S. (2013). Revisiting a Sample of U.S. Billionaires: How Sample Selection and Timing of Maternal Condition Influence Findings on the Trivers-Willard Effect. PLoS ONE 8(2): e57446. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0057446

Song, S. (2012). Does famine influence sex ratio at birth? Evidence from the 1959–1961 Great Leap Forward Famine in China. Proceedings of the Royal Society B 279(1739):2883-2890. http://rspb.royalsocietypublishing.org/content/early/2012/03/16/rspb.2012.0320.full

Thogerson C.M., Brady, C.M., Howard, R.D., Mason, G.J., Pajor, E.A., Vicino, G.A., and Garner, J.P. (2013) Winning the genetic lottery: biasing birth sex ratio results in more grandchildren. PLoS One 8(7):e67867. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0067867

Trivers, R.L., and Willard, D.E. (1973). Natural selection of parental ability to vary the sex ratio of offspring. Science 179: 90-92. http://www.sciencemag.org/content/179/4068/90.abstract


Photo credits:

Elephant Seal 1
Photo by: Roy Mangersnes
http://roywildphoto.blogspot.com/2008/11/elephant-seals.html

Elephant Seal 2
Photo by: Mike Baird
https://www.flickr.com/photos/mikebaird/11830159673/

White tailed deer
Photo by: Public Domain
http://en.wikipedia.org/wiki/File:White-tailed_deer.jpg

Key Deer
Photo by: IanarÈ SÈvi
http://commons.wikimedia.org/wiki/File:Odocoileus_virginianus_clavium_fawn.jpg

Male Lion
Photo by: Wikimedia user Robek
http://commons.wikimedia.org/wiki/File:Pair_of_lions_v2.jpg

Baby Lion
Photo by: Flickr user fortherock
https://www.flickr.com/photos/fortherock/3897872187/

Brad Pitt
Photo by: Foreign and Commonwealth Office
http://www.flickr.com/photos/foreignoffice/14217374639/

Kids
Photo by: Barbara Hobbs
http://commons.wikimedia.org/wiki/File:Upclose_of_kids_-_Alberti_Flea_Circus,_MerleFest_2013.jpg

Tagged under: MinuteEarth,Minute Earth,MinutePhysics,Minute Physics,earth,history,science,environment,environmental science,earth science,Sex,Sex Ratio,china,india,preference, boys,boys girls,boys girls,XY,XX,Chromosome,male,female,reproduction,XY Sex-determination System,Biology (Media Genre)