The Beard is beard and muffs. The no beard lost the muff/bearded gene - just something the hatcheries do when they loose one of the genes necessary for fuzzy faces. Some of them even look like they have a single comb??? One breeder of Wheaten Ameraucanas also lost one half of the bearded/muffs gene - but she notes it when she sells eggs/chicks that they may only have one gene - and to remove the chicks not showing super fuzzy faces at birth and not use them for breeding. She is working on fixing that though.
Ironically, I just had a pretty indepth discussion about this very topic with Mike Gilbert on the ABC Forum. According to Mike the muff/beard gene is one gene although he indicated on some of the other genetic threads he's following there is some discussion about whether that is actually the case. He's already forgotten more about genetics than I'll learn in a lifetime so until I hear differently from him, I'm going with it being a single gene. It is referred to as Mb or mb and each parent contributes one gene. So it can be either homozygous or heterozygous.
So the above isn't technically correct. No beard birds didn't lose the muff/beard gene, they just came from two heterozygous parents that did not contribute a Mb because Mbmb (hetero) would still be bearded and have muffs. Though they would be more sparse than a homozygous bird. Therefore, the one breeder of Wheaten Ameraucanas, in my opinion, is jumping the gun to advise calling any chicks "not showing super fuzzy faces at birth" and "not use them for breeding".
I say this after my discussion with Mike about using a Splash Wheaten cockerel that I'm almost 100% positive is Mbmb (hetero). I don't have time right now to go into it all so suffice it for now to say there are some very good reasons for using a hetero muffs/bearded bird. Several in fact.
God Bless,
Royce