Genetic advantage of single over pea comb

[Red Mangrove]

Plenty of mutations were the result of accidents that were then brednby people because they liked the look

The code was already there inside of the bird. Rhode Island Reds didn't magically get their red color, they got it from Malay ancestors and then a man specifically bred for that color he found in the Malay DNA

Pea combs are too useful and widespread to be an accident from inbreeding distorting DNA in my opinion, though to be fair I'm just a peasant and not a geneticist

 

[JacinLarkwell]

The code was already there inside of the bird. Rhode Island Reds didn't magically get their red color, they got it from Malay ancestors and then a man specifically bred for that color he found in the Malay DNA

Pea combs are too useful and widespread to be an accident from inbreeding distorting DNA in my opinion, though to be fair I'm just a peasant and not a geneticist

Pea combs have been around for decades at the very least, probably more like centuries. Plenty of time for things to be transfered all over the world, just like cats and rats have been.

Plus there are cases were seperate groups of an animal develop certain traits at seperate times. I forget the name of it, but pretty sure there was a study of lizards or finches on some island about it. I'll try to find what it was called

 

[fluffycrow]

There's nothing in nature that occurs as an accident. The pea comb came from somewhere and it served a specific genetic purpose wherever it originated

Your theory about an unknown junglefowl ancestor (in southeast Asia?) is probably correct


I have some very fat Brahma X Orpington here and I've never noticed their behavior in regards to temperature being any different from my single combs. My flock all engages in nearly identical behavior regardless of their comb. Perhaps it's because they have cold water outside here, or maybe it's a coop specific issue

Since the brahma coop is one of my most well-ventilated ones, it's shady day round, and as mentioned before has cool water for them, I'm inclined to believe it's not coop-related. Orpington and brahma crosses would produce modified peas, which as with the example of my male, cope a little better

 

[JacinLarkwell]

Pea combs have been around for decades at the very least, probably more like centuries. Plenty of time for things to be transfered all over the world, just like cats and rats have been.

Plus there are cases were seperate groups of an animal develop certain traits at seperate times. I forget the name of it, but pretty sure there was a study of lizards or finches on some island about it. I'll try to find what it was called

I was thinking of Parallel Evolution. Blue eggs and black skin are also ones that developed at different places at different times

 

[Red Mangrove]

Since the brahma coop is one of my most well-ventilated ones, it's shady day round, and as mentioned before has cool water for them, I'm inclined to believe it's not coop-related. Orpington and brahma crosses would produce modified peas, which as with the example of my male, cope a little better

I thought pea combs were dominant. I had an Ameraucana breed a bunch of my single combed hens around here and every single one of his offspring inherited pea combs

Maybe these are the "modified pea" you mentioned

 

[NatJ]

There's nothing in nature that occurs as an accident. The pea comb came from somewhere and it served a specific genetic purpose wherever it originated

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.

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

Single combs are also removed by cockfighters because they present a physical liability during combat

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.

Are there any genetic advantages to having a single comb over a pea comb?...
Are pea combs simply genetically superior?

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.

 

[NatJ]

I thought pea combs were dominant. I had an Ameraucana breed a bunch of my single combed hens around here and every single one of his offspring inherited pea combs

Maybe these are the "modified pea" you mentioned

Technically, pea comb would be considered "incompletely dominant."

One copy of the pea comb gene makes a comb that is recognizably different than a single comb. But it usually looks different than the comb on a chicken with two copies of the pea comb gene. The wattles are usually normal sized (the size you would expect on a chicken with single or rose comb.)

Two copies of the pea comb gene make the tidy little pea comb we expect in purebred pea comb chickens, and also makes the wattles much smaller.

Because of the differences, many people say "pea comb" for the version with two copies of the gene, that is found in various pure breeds of chicken. Then they call the one-copy version a "modified pea comb," because it looks different (usually bigger, often rather blobby or untidy or otherwise a bit different in shape.)

 

[FunClucks]

I thought pea combs were dominant. I had an Ameraucana breed a bunch of my single combed hens around here and every single one of his offspring inherited pea combs

Yes, pea combs are dominant.

 

[fluffycrow]

The thing with gamefowl, especially Oriental gamefowl, is that they are rather lacking in feather abundance compared to say, a brahma, or most birds really. Like I said above, I keep chickens in a climate that is rather hot. My straight comb birds do a lot better, and even my heterozygous pea birds do ok. Do I think that comb is the most important thing when it comes to heat protection? No. But for me the fact that the bird I showed above, with a really large comb and wattles, who by the way is much more abundant in the feathered department than my gamefowl male, is proof enough. But that's just me. I've seen what works better and I'm sticking to it. Something else might work better for someone else

 

[Florida Bullfrog]

If I remember and have time, I’ll take out the thermal scope at dark and take some pics of pea and straight combed birds

Actually I’ll have to hit the office this evening, but I can do it tomorrow evening.