Question: "Did Jacob placing branches in front of his flock really result in the offspring being speckled and spotted?"
Answer: In Genesis 30 Laban asked Jacob to “name his wages,” and Jacob said, “Let me go through all your flocks today and remove from them every speckled or spotted sheep, every dark-colored lamb and every spotted or speckled goat. They will be my wages. And . . . in the future . . . any goat in my possession that is not speckled or spotted, or any lamb that is not dark-colored, will be considered stolen” (Genesis 30:32–33). Laban agreed, and the animals were divided. Laban separated out the multi-colored animals, leaving only the solid-colored animals for his son-in-law to tend. The agreement seemed to favor Laban, as speckled or spotted sheep and goats were the exception, not the rule.
To increase his flocks (and diminish Laban’s), Jacob instituted some sort of folk-medicine selective breeding process. He took fresh-cut branches from poplar, almond, and plane trees and peeled the bark to create white stripes on them. “Then he placed the peeled branches in all the watering troughs, so that they would be directly in front of the flocks when they came to drink. When the flocks were in heat and came to drink, they mated in front of the branches. And they bore young that were streaked or speckled or spotted” (Genesis 30:38–39). It is unclear how or if these striped branches impacted the mating of the animals. The Bible simply records what Jacob did and the result in the flock, with no explanation.
An ancient breed of sheep, still raised today, is the Jacob sheep, which has the distinction of having multi-colored fleece. The black-and-white spotted wool is highly prized for handspinning, or roving. This breed is called “Jacob sheep” because some trace its origin to the story of Jacob’s selective breeding of sheep in Genesis 30.
In addition to increasing the number of spotted animals, Jacob also wanted to make sure that the spotted ones were stronger than the rest. He only placed the branches in the troughs when the stronger females were in heat, “but if the animals were weak, he would not place them there” (Genesis 30:42). The result was that the stronger of the flock were multi-colored, and the weaker were normal colored. In the end, Jacob “grew exceedingly prosperous and came to own large flocks” (verse 43).
Some try to find a natural explanation to the account of Jacob’s striped branches and the resulting speckled flocks. Some theorize that Jacob, through a lifetime of experience with sheep, knew that something in the branches would cause the animals to be sexually stimulated and to mate more often. He placed the branches strategically to breed those animals more likely to produce speckled and spotted offspring.
A better view is that the God of Abraham, Isaac, and Jacob supernaturally intervened to increase Jacob’s flocks. Jacob may have relied on his own efforts, tainted as they were by pastoral folklore, but God had determined to bless him.
The biblical answer to the mystery of how Jacob’s peeled poles resulted in speckled sheep is found in the next chapter: Jacob says to Rachel, “I’ve worked for your father with all my strength, yet your father has cheated me by changing my wages ten times. However, God has not allowed him to harm me. . . . So God has taken away your father’s livestock and has given them to me. In breeding season I once had a dream in which I looked up and saw that the male goats mating with the flock were streaked, speckled or spotted. The angel of God said to me in the dream, . . . ‘Look up and see that all the male goats mating with the flock are streaked, speckled or spotted, for I have seen all that Laban has been doing to you’” (Genesis 31:6–12).
The Bible does not teach the validity of visual, prenatal influence over genetics. Whatever superstitious, nonsensical ideas were behind Jacob’s placement of the branches in the troughs, it was God who caused the increase in the speckled sheep and goats. All of Jacob’s work had been for naught. Peeling the branches and setting them out in front of the flocks was really a lack of faith on his part. Jacob’s schemes to increase his flock were unnecessary, because God had already determined to enrich him. God graciously worked, not because of Jacob’s streaked branches, but in spite of them.