In Genesis 30:31-39, Laban takes away all of the spotted and striped sheep and goats that Jacob wants, leaving Jacob with plain sheep and goats that don't have spots and stripes. So Jacob takes some tree branches and makes them look striped, then puts the tree branches by his flocks so that when they mate, they will see the striped branches and their offspring will have spots and stripes. And his plan works. The flocks look at the branches that appear to have stripes, and then conceive and give birth to lambs/kids that have stripes and spots and speckles.
In other words, you can make sheep and goats have spotted/striped babies by showing them things with stripes on them.
That's not really how genetics work, is it? Surely this is folklore that just found its way into the Old Testament, isn't it?
Nope. It's a true story, as we learn in an official LDS Institute manual.
Old Testament Student Manual, Religion 301, Genesis--2 Samuel, pg. 88
(7-19) Genesis 30:37–43. Did the Peeled Rods
Influence the Conception of the Flocks of Jacob?
Jacob’s peeling of branches and placing them before the animals so that when they conceived they would bear multicolored offspring seems to be a reflection of a common superstition that the conception of offspring is influenced by what the mother experiences or sees at the time of conception. Nothing is known by modern science to explain any relationship between what Jacob did and what happened in the hereditary patterns of the animals. Perhaps something is missing from the text. Perhaps the Lord was just taking advantage of the virility of crossbred animals. Divine intervention certainly played a part. In any event, Jacob’s herds grew and the Lord blessed him. Also, Jacob’s separation of the flocks (v. 40) follows principles of good animal husbandry and would have increased the likelihood of having multi-colored animals.P.S. For those of you who are just joining us, the topic of this thread is how the LDS Church is most definitely not a biblical literalist religion.
ETA: The Genesis 30 Laban is not the same Laban that Nephi turned into a Pez dispenser. Just thought I should clarify that.