Wed, 25 October 2017
Thanks to 23andMe for sponsoring this video! http://www.23andme.com/minuteearth Male birds have the largest genital diversity of any class of animals because their sex chromosomes make it easy to pass male-helping mutations down the line. Thanks also to our supporters on https://www.patreon.com/MinuteEarth To learn more, start your googling with these keywords: If you liked this week’s video, you might also like: Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Say hello on Facebook: http://goo.gl/FpAvo6 And download our videos on itunes: https://goo.gl/sfwS6n Credits (and Twitter handles):
References: Brennan, P. and Prum, R. (2015). Mechanisms and Evidence of Genital Coevolution: The Roles of Natural Selection,Mate Choice, and Sexual Conflict. 1-21. Cold Spring Harbor Perspectives in Biology. Retrieved from: http://cshperspectives.cshlp.org/content/7/7/a017749.abstract Brennan, P. (2013). Genital Evolution: Cock-a-Doodle-Don’t. Current Biology. R523-R525. Retrieved from: http://www.sciencedirect.com/science/article/pii/S0960982213004430 Brennan, P., Birkhead, T., Zyskowski, K., van der Waagand, J., and Prum, R. (2008). Independent evolutionary reductions of the phallus in basal birds. Journal of Avian Biology, 39: 487-492. Retrieved from: http://onlinelibrary.wiley.com/doi/10.1111/j.0908-8857.2008.04610.x/abstract. Briskie, J. and Montgomerie, R. (1997). Sexual selection and the intromittent organ of birds. Journal of Avian Biology. 28: 73-86. Retrieved from: https://www.jstor.org/stable/3677097?seq=1#page_scan_tab_contents Herrera, A., Brennan, P., and Cohn, M. (2014). Development of Avian External Genitalia: Interspecific Differences and Sexual Differentiation of the Male and Female Phallus. Sexual Development. 9: 43-52. Retrieved from: https://www.ncbi.nlm.nih.gov/pubmed/25011524. Reinhold, K. (1998). Sex linkage among genes controlling sexually selected traits. Sexual Selection. 44:1-7. Retrieved from: https://link.springer.com/article/10.1007/s002650050508. Image Credits: Mandarin Ducks - Francis C. Franklin Gorillas - Based on photo by Wikimedia user No escape Lake Duck Penis - Kevin McCracken (Published in Nature 2001) |
Thu, 12 October 2017
The incredible chemical weapon-making abilities of fungi, bacteria, and plants have created an incredible array of compounds that are useful to humans. Thanks to the University of Minnesota for sponsoring this video! http://twin-cities.umn.edu/ Thanks also to our supporters on https://www.patreon.com/MinuteEarth To learn more, start your googling with these keywords: Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Say hello on Facebook: http://goo.gl/FpAvo6 And download our videos on itunes: https://goo.gl/sfwS6n Credits (and Twitter handles):
References: Bills, G.F. and Gloer, J.B. (2016) Biologically Active Secondary Metabolites from the Fungi. Microbiology Spectrum 4(6): 6 Cragg, G.M. and Newman, D.J. (2005) Biodiversity: A continuing source of novel drug leads. Pure and Appled Chemistry 77: 7–24 Mazid, M., Khan, T.A. and Mohammad, F. (2011) Role of secondary metabolites in defense mechanisms of plants. Biology and Medicine 3(2): 232–249. Newman, D.J. and Cragg, G.M. (2016) Natural Products as Sources of New Drugs from 1981 to 2014. Journal of Natural Products 79: 629-661 O’Brien, J. and Wright, G.D. (2011) An ecological perspective of microbial secondary metabolism. Current Opinion in Biotechnology 22:552–558 |
Wed, 4 October 2017
Female hyenas don't have penises, but it sure looks like they do - and we still aren't quite sure why. To start using Tab for a Cause, go to: http://tabforacause.org/r/minuteearth2 Thanks also to our supporters on https://www.patreon.com/MinuteEarth To learn more, start your googling with these keywords: If you liked this week’s video, you might also like: Hyena having a baby at the Buffalo Zoo Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Say hello on Facebook: http://goo.gl/FpAvo6 And download our videos on itunes: https://goo.gl/sfwS6n Credits (and Twitter handles): Video Credits: Image Credits: Striped Hyena (Hyaena hyaena) - Flickr user Jean Brown Hyena (Parahyaena brunnea) - Bernard DUPONT Proteles cristatus - Dominik Käuferle Squirrel monkey - Wikimedia user Megapixie Ring tailed lemur - Wikimedia user Sannse Fossa - Ran Kirlian Binturong - Tassilo Rau ___________________________________________ References: Cunha GR, Risbridger G, Wang H, Place NJ, Grumbach M, Cunha TJ, Weldele M, Conley AJ, Barcellos D, Agarwal S, Bhargava A, Drea C, Hammond GL, Siiteri P, Coscia EM, McPhaul MJ, Baskin LS, Glickman SE. (2014) Development of the external genitalia: perspectives from the spotted hyena (Crocuta crocuta). Differentiation. 87(1-2):4-22. http://www.sciencedirect.com/science/article/pii/S030146811300087X?via%3Dihub Frank LG (1997) Evolution of genital masculinization: why do female hyenas have such a large 'penis'? Trends Ecol. Evol. 12:58-62. http://www.cell.com/trends/ecology-evolution/abstract/S0169-5347(96)10063-X Frank LG and Glickman SE (1994) Giving birth through a penile clitoris: parturition and dystocia in the spotted hyaena (Crocuta crocuta). J. Zool. 234:659–665. http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.1994.tb04871.x/abstract Frank LG, Weldele ML, and Glickman SE (1995) Masculinization costs in hyaenas. Nature 377:584–585. http://www.nature.com/nature/journal/v377/n6550/abs/377584b0.html?foxtrotcallback=true Glickman SE, Cunha GR, Drea CM, Conley AJ and Place NJ (2006) Mammalian sexual differentiation: lessons from the spotted hyena. rends in Endocrinology and Metabolism 17 (9): 349–356. http://www.sciencedirect.com/science/article/pii/S1043276006001767 Holekamp, KE, personal communication. August and September 2017. Muller MN and Wrangham R (2002) Sexual Mimicry in Hyenas. The Quarterly Review of Biology 77 (1):3-16. http://www.journals.uchicago.edu/doi/abs/10.1086/339199?journalCode=qrb
Direct download: Why_Do_Female_Hyenas_Have_Pseudo-Penises-.mp4
Category:general -- posted at: 10:01am EDT |