Hybrid Vigor

Hybrid vigor is a phenomenon in which crossbreeding of different species results in increased vigor in the hybrid (1). This is also called heterosis which is defined as of the presence of any sort of increased beneficial characteristic in the hybrid that is not present in the parents. Hybrid vigor was first studied by Charles Darwin (3). This can affect things such as organism size, plant yield from seed, or how fast an organism grows (2). All of this is accomplished basically by the increase of certain cell tissues, but not all cell tissues in the hybrid (3). Hybrid Vigor often results from a combination of heterozygotes of different species (3).

Hybrid Vigor has had a significant influence on agriculture and food production. Corn is an excellent example of this because many hybrids and even double hybrids are grown commercially. When strains of corn from different geographic regions are bred together the F1 generation often shows hybrid vigor (4).

References
 * 1) American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 * 2) Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
 * 3) Unraveling the genetic basis of hybrid vigor. (n.d.). Retrieved April 7, 2015, from http://www.pnas.org/content/103/35/12957.full
 * 4) Demin, Y. (n.d.). HETEROSIS. Retrieved April 7, 2015, from http://www.fao.org/docrep/005/b3310e/B3310E08.htm