Thursday, January 25, 2024

The Genetics of the Birds and the Bees

Birds hybridize all the time. 

Barred Owls will mate with Spotted Owls, Canaries with Goldfinches, Mallards with Black Ducks, etc.  

Astoundingly, a Golden Eagle has even been crossed with a Harris Hawk, and they’re not even the same genus! 

The mind reels…

Hybridization is essential to life.  It is the watch spring of evolution, as Darwin observed.

Darwin’s finches on the Galapagos islands, for example, survived because the initial rootstock that blew over from South America contained, within it, the genetic possibility to express several different beak types variously suitable to different islands and different flora, fauna, and rain patterns on those islands. Some years, the rain favors a short heavy beak, and other years the rain favors a longer, curved beak. Genetic variability is essential to finch survival, and it’s perhaps no accident that so many species of finch the world over will hybridize with so many others.

The possibility of hybridization exists in many species, while inbreeding is generally discouraged in most wild animal populations.

For example young male fox and wolves are generally driven out of their natal areas to order to force them to find unrelated mates elsewhere. Inbreeding is simply maladaptive, and so behavior patterns generally discourage it. There are some exceptions (whiptail lizards, for example), but not too many.

Curiously, the push to hybridize and outcross even exists in bee hives.  

There are three basic types of bees:  Queens, drones, and workers.  A hive will typically have one queen, a few hundred male drones, and 20,000 to 60,000 sterile female workers with shifting responsibilities depending on their age.

In most hives, the queen is not inseminated by her own hive drones.  Instead, a young virgin queen flies out into forest and field and meets up with random drones from other hives. There she may be inseminated by half a dozen drones, each of whom will deviscerate themselves while mating her (they throw themseves backwards after penetration, pulling their guts out in the process). 

The young fertilized queen will now remain fertilized for the rest of her life, her eggs representing the diverse genetics of her wild mates and her own.

In short, bees tend to gravitate towards mutts.  

You may spend $200 acquiring a pure Russian queen, putatively more resistant to mites and viruses, but the hive itself will soon swarm, create new queens, and outcross to other genes in fairly short order.

Mother nature likes a hybrid and cares nothing for your investment in an expensive Russian queen.  

Mother Nature and Father Time have calculated that the best long-term odds for bee survival depends on bee genetic diversity.

Mutt bees rule. Go figure.

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