Dear Emmie,
When I want something sweet, I pull out a jar of honey made by my bee friends at Washington State University. I talked about your question with one of the insect scientists there, Rae Olsson.
They told me a honey bee colony includes one female queen, many female workers and, depending on the time of year, some male drones.
Workers have lots of jobs. They gather nectar and pollen. They take care of each other, the queen and the baby bees.
A drone’s only job is to mate with a queen from another colony.
The queen’s only job is to make more bees. A mated queen stores sperm cells from male bees in a little pouch. Then, she can decide whether to lay female eggs or male eggs. Eggs fertilized with sperm become female bees. Unfertilized eggs become male bees.
It works that way because bees and their relatives are haplodiploid.
Most animals—including humans like you and cats like me—are diploid. That means we have “double” copies of our genes. Genes are like DNA instructions your cells use. Some of your genes influence the traits that make you, you. Like your eye color or how shy you are.
A diploid animal has two copies of its genes because it comes from a fertilized egg. It gets one copy from the egg cell and one copy from the sperm cell.
Female bees are diploid with two copies of their genes, too. But male bees only have one copy of their genes. They’re haploid.
So, if something wiped out all the male honey bees, queens could just lay more male eggs. If those new drones matured in time to mate with the new queens, everything would be fine.
If male bees didn’t exist at all—like the idea of male bees vanished or there wasn’t time for new male eggs to mature—queen bees wouldn’t be able to lay fertilized eggs. That means no new workers and no new queens.
“The workers are like 98% of the hive,” Olsson said. “So, within a pretty short period of time there would be no female honey bees to take care of the colony.”
But cape honey bees in South Africa have a cheat code for emergencies that could save them—even if male bees were gone forever. If the queen bee dies, the workers can lay unfertilized eggs that become female bees instead of male bees.
Thanks to a quirk in the cape honey bees’ egg-making process, the egg cell contains two sets of genes instead of one set. The new bees are clones, or exact copies of the worker bee.
“They could have whole lines of just female bees without males,” Olsson said. “But they’re losing out on the genetic trait changes that might happen with fertilized eggs.”
The reason animals fertilize their eggs is to mix up the genes. It’s like shuffling a deck of cards. You probably aren’t going to get the exact same cards you had before you shuffled.
When every animal in a group has a different mix of genes, the group can adapt better to changes in their environment. There’s probably someone in the group who can survive whatever life throws at them.
Still, making cloned workers is a pretty sweet way cape honey bees already adapted. You could say it’s their plan bee.
Sincerely,
Dr. Universe