I’ve researched the Terah – Abraham genealogy and I see evidence of a hereditary transmission in this family of a peculiar Infertility/Twinning syndrome. Recent data about a similar syndrome appears in contemporary genetic literature. My question is does it make sense that Isaac did not have concubines in spite of the fact that he experienced 20 years of infertility with Rebecca and the fact that his father Abraham and his son Jacob both had concubines mentioned in Bible?
I will try and answer your various questions on a scientific and Biblical basis.
1st) Science teaches that there are dominant and recessive traits. Science also allows us to predict expected frequency in offspring of dominant and recessive traits. Certain traits for example may only appear in 25% of the offspring while others may appear in 50% or 100%.
So even if you ascribed the infertility to genetic causes it is not clear that having one exception (Isaac) would contradict anything. The statistics (2 vs 3) are too small in this case.
2nd) The Bible does not describe infertility. It rather describes DELAYED fertility. Psychology has shown that numerous causes can DELAY the first child. Not all of them are genetic. All the Patriarchs had a lot of suffering and stress can delay the 1st child. I would be interested if you carefully explored environmental as well as genetic causes.
3rd) All 3 patriarchs and all 4 matriarchs had children. Thus Isaac came from Abraham and Sarah; Jacob came from Isaac and Rivkah; Reuven came from Jacob and Leah while Joseph came from Jacob and Rachel.
As to the Biblical sources for the concubines: a) Abraham married his concubine Hagar after 10 years of lack of children by Sarah (Genesis 16). b) Jacob married the concubines of his two wives (Gen. 30) but the Bible indicates that this was an “act of competitive jealousy” and not based on a 10 year “delay” in having children. (In passing, and I don’t know if you are interested in this, but we can actually partially calculate the birth dates of the 12 tribes and this can be used to show that a 10 year interval was not involved. Write back if you are interested) c) We have no explicit source that Isaac did not have a concubine. Rather, we have omission of any mention of a concubine and from this we infer that Isaac did not have a concubine. However it would not contradict the Bible to say he did. However since the presence of a concubine causes so much marital friction we think it reasonable that the omission of mention of a concubine is proof that he had no concubine.
I hope the above answers most of your questions. I would seriously urge you to review both the probabilistic and psychological issues.
Dr. Russell Jay Hendel;