37 And Jacob took him rods of green poplar, and of the hazel and chestnut tree; and pilled white strakes in them, and made the white appear which was in the rods. 38 And he set the rods which he had pilled before the flocks in the gutters in the watering troughs when the flocks came to drink, that they should conceive when they came to drink. 40 And Jacob did separate the lambs, and set the faces of the flocks toward the ringstraked, and all the brown in the flock of Laban; and he put his own flocks by themselves, and put them not unto Laban’s cattle. 41 And it came to pass, whensoever the stronger cattle did conceive, that Jacob laid the rods before the eyes of the cattle in the gutters, that they might conceive among the rods. 42 But when the cattle were feeble, he put them not in: so the feebler were Laban’s, and the stronger Jacob’s. 43 And the man increased exceedingly, and had much cattle, and maidservants, and menservants, and camels, and asses.
I had always read these verses as saying that goats who conceived while looking at striped sticks would give birth to striped children, which sounded superstitious and unscientific. Reading this again, though, I noticed it said that Jacob put the poplar, hazel, and chestnut sticks in the watering trough, which seems to suggest that they were being used for medicinal qualities to strengthen the goats as they conceived.
But he did not place them before all the cattle, only the ones that belonged to him. Furthermore, verse 40 shows that Jacob did not let his livestock mate with Laban’s, most likely to preserve the recessive gene that caused mottles or stripes in their coats. Thus, Jacob was able to artificially increase the number of speckled goats above the others, and he made them stronger and healthier at the same time.
I was wrong in my past readings of these verses. Jacob was employing shrewd tactics that were based upon a logical procedure, and as a result he came to exceed his own father-in-law.