Genetic advantage of single over pea comb

[Finnie]

The code was already there inside of the bird.

Actually, in the case of mutations, the code was not already there in the bird. That’s what a mutation is, a change in the DNA from what was there to something different.

That change is usually an accident. These accidents in replication happen all the time. They go unnoticed unless they happen to damage the way something works and cause a noticeable difference. Then we see a new form occur that had never occurred before. Due to an actual change in the DNA.

 

[Auntiejessi3]

Pea combed breeds live perfectly in many different places though, including many very hot places. Clearly heat alone is irrelevant. Perhaps humidity is the missing factor here

I have a light brahma and live in Central Texas, she does amazingly well in the heat and humidity

 

[Florida Bullfrog]

Actually, in the case of mutations, the code was not already there in the bird. That’s what a mutation is, a change in the DNA from what was there to something different.

That change is usually an accident. These accidents in replication happen all the time. They go unnoticed unless they happen to damage the way something works and cause a noticeable difference. Then we see a new form occur that had never occurred before. Due to an actual change in the DNA.

What we’re learning about DNA is that many or most mutational possibilities are already built into the genome of the animal. They are merely activated or deactivated, and its usually not accidental. Change is rapid and purposeful, and DNA like a Swiss Army knife that pulls out needed modifications as conditions change.

Molecular biology is rapidly proving much of what we believe about how evolution works to be wrong.

https://www.thethirdwayofevolution.com/

 

[Red Mangrove]

Your point about cockfighters removing single combs (dubbing) is interesting, because some of them are in hot places. If the dubbed birds fare poorly and the un-dubbed birds are fine, it would be pretty good evidence that comb type matters in the heat. If all the birds do equally well, it would strongly suggest that a small comb (dubbed or pea) is just as good as a normal single comb in hot weather.

I would never expect an amputated organ to function as well as a natural and healthy one. Your other points are insightful though

 

[Finnie]

What we’re learning about DNA is that many or most mutational possibilities are already built into the genome of the animal. They are merely activated or deactivated, and its usually not accidental.

Very interesting information to be found on this subject. Interesting rabbit hole I went down this morning.

 

[RobG7aChattTN]

Lots of mutations occur as an accident. The harmful ones die out quickly, the helpful ones get spread, and the ones that people specially select will become common in captive chickens.

Things like crest, muff/beard, silkie feathers, and frizzle feathers would all be disadvantages in wild chickens. But people like them, so the people keep breeding them.

The pea comb mutation happened at some point, and some people kept breeding it, so it is still around in domestic chickens.




People in cold climates have been more likely to select for pea combs, but they are also more likely to select for chickens with large amounts of feathers (like Brahmas and Orpingtons.) To see if pea comb is a problem in hot weather, I would look at pea comb chickens from hotter places (examples: Cubalaya, Sumatra, Aseel). I would also look at some of the Easter Eggers that have large amounts of Leghorn in their heritage (example: Whiting True Blue from McMurray hatchery.) That should make it a comb difference only, not a comb + feathers difference.

Your point about cockfighters removing single combs (dubbing) is interesting, because some of them are in hot places. If the dubbed birds fare poorly and the un-dubbed birds are fine, it would be pretty good evidence that comb type matters in the heat. If all the birds do equally well, it would strongly suggest that a small comb (dubbed or pea) is just as good as a normal single comb in hot weather.

I have never lived in a place that gets very hot, so I don't have any personal observations of pea comb vs. single comb chickens in hot places.



I know of at least three points against pea combs:

--Pea combs are smaller, so it is harder for people to recognize male chicks when they are young. This does not hurt the chicken, but is a point that matters to some people. (I read of one breed-in-development that has single combs for exactly this reason.)

--The pea comb gene also causes a strip along the breastbone that has no feathers. This does not seem to bother the chicken, but does affect how it looks after butchering (different texture to the skin there.) This matters to some people raising chickens for meat (especially commercial meat-producers.) I can't remember whether this happens only in chickens homozygous (pure) for pea comb, or if it happens in the heterozygotes (split) as well.

--I have noticed that roosters seem more attracted to hens with single combs rather than pea combs, probably because the single comb is larger and more obvious. Roosters tend to mate with the laying hens (big red combs) and not with immature pullets (small combs). If the rooster considers the pea comb hens to be less desireable, this could potentially be an issue in a flock with mixed comb types. In practice, it does not seem to be a big deal in most flocks, because most roosters end up mating with all the hens often enough and with their favorite hens more often than that. I would not expect it to be a problem in flocks with only pea combs.

Personally, I like pea combs better than any other comb type, and I do not see them causing harm to chickens (but I'm not in a very hot climate). But any person can have different preferences about what comb looks best to them, and the points I listed can be important to some people.

When hens are allowed to “self-select” they always choose the roosters with the biggest, reddest combs. Big combs help the birds shed heat which is a big advantage for all the current wild jungle fowl because they are all tropical. With gamefowl I think they dub the combs, wattles and earlobes the same way that human boxers get their nose broken before actually boxing in a boxing match. It might not be beneficial in the grand scheme of things but might have an advantage in a fight. Fighting birds get dubbed to remove what is easy to grab ahold of and what bleeds profusely but also get feathers removed to help them shed heat. I need to look for the photos of Sumatra chickens in Indonesia to see if they have pea combs. I know they don’t have long tails as those were added in Europe later. Lots of genetic mutations occur spontaneously and are perpetuated for reasons that would make them less fit for the wild. Think of the Polish that can’t even see in front of themselves. In the wild they don’t last long.

 

[DarJones]

Single comb is an advantage in hot climates. Light body size is also an advantage. Light colored feathers are another heat advantage.

What about cold climate advantages? Pea comb, rose comb, cushion comb, and flat comb are all advantaged to different degrees in cold climates. But it takes a lot more to make a cold weather adapted chicken. Large body size, thick fluffy feathers, and yellow legs are all advantages in cold climates. How so? Large body size and thick fluffy feathers are better for generating and retaining heat. Yellow legs are from sequestering caroteinoids. Guess what a chicken needs to lay eggs? Yes, carotene! Where does carotene come from? It comes from grass and plants chickens eat. In a cold climate, there is a shortage of green plants in winter. Yellow leg chickens have a small but significant advantage. Also, midden heaps prove all chickens from 2000 years ago had white legs. As they moved further from the equator, yellow legs became more and more common. We know yellow legs came from green junglefowl along with several other traits needed in cold climates.

 

[JacinLarkwell]

When hens are allowed to “self-select” they always choose the roosters with the biggest, reddest combs. Big combs help the birds shed heat which is a big advantage for all the current wild jungle fowl because they are all tropical. With gamefowl I think they dub the combs, wattles and earlobes the same way that human boxers get their nose broken before actually boxing in a boxing match. It might not be beneficial in the grand scheme of things but might have an advantage in a fight. Fighting birds get dubbed to remove what is easy to grab ahold of and what bleeds profusely but also get feathers removed to help them shed heat. I need to look for the photos of Sumatra chickens in Indonesia to see if they have pea combs. I know they don’t have long tails as those were added in Europe later. Lots of genetic mutations occur spontaneously and are perpetuated for reasons that would make them less fit for the wild. Think of the Polish that can’t even see in front of themselves. In the wild they don’t last long.

I can somewhat agree based on my mixed flock. But I also have noticed that if they can't be bred by the single combed male, then their second choice is the araucana male (small, tight comb) and not my male that is a heterozygous pea comb. He is almost always the one they refuse to squat for and rarely fathered chicks this year

 

[Red Mangrove]

Yellow legs are from sequestering caroteinoids. Guess what a chicken needs to lay eggs? Yes, carotene! Where does carotene come from? It comes from grass and plants chickens eat. In a cold climate, there is a shortage of green plants in winter. Yellow leg chickens have a small but significant advantage.

Laying eggs in winter in a cold climate doesn't sound like an evolutionary advantage to me. That's good for humans but terrible in terms of survival for chickens, given the wasted calories expended on dead eggs

 

[Florida Bullfrog]

Straight and pea comb rooster comparison. Similar housing for both birds (wire coop with tarp top, wooden roosting branch, about the same height off the ground.