From: [EMAIL PROTECTED] Subject: [OGD] Re: genetics of hybrids
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Actually, Mendel dictates that a first-generation primary hybrid will have exactly 50% contribution from each parent species (ignoring minor contributions from maternally inherited DNA in mitochondria and chloroplasts). It is in later generations of a cross that things become less certain. That's why those charts, so popular in orchid books, that claim a certain hybrid is 25% species X and 12.5% species Y are pretty silly.
Of course, that doesn't mean that all siblings of a particular primary hybrid cross will look identical. Variation in the offsping will be dependent on the degree of heterozygosity in the parents, but those offspring will all still be 50% each parent.
Nick
Nick, I am afraid you are mistaken. It is only 50/50 if and when you postulate a single gene and if and when there are no dominances involved and if there is no crossover etc. etc. etc. Thus only if you have a "monohybrid" This only occurs "theoretically" in biology text books. Just check Mendel's laws .... there is plenty avout that on the internet. regards Guido -- Prof. Dr. Guido J. Braem Naunheimer Str. 17 35633 Lahnau Deutschland/Germany _______________________________________________ the OrchidGuide Digest (OGD) [email protected] http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com
