Genetic Things
Genetic Things
Interesting, in this list of human traits with simple inheritance patterns, I would have thought smooth chin was dominant and cleft chin recessive, since I rarely see people with cleft chins. I suppose that list is a gold mine of "what are you?" discussion.
Updated: I guess I misunderstood. I think "recessive" is the more common (the way they made the list), since "normal number of fingers" is in the recessive column. When I think dominant in terms of Mendelian genetics, I think of "if at least one of them is X, you get X trait" and recessive is "you need both to be X to get X trait."
Updated: I guess I misunderstood. I think "recessive" is the more common (the way they made the list), since "normal number of fingers" is in the recessive column. When I think dominant in terms of Mendelian genetics, I think of "if at least one of them is X, you get X trait" and recessive is "you need both to be X to get X trait."
Last edited by Digit on Wed Feb 06, 2013 8:30 am, edited 1 time in total.
Quod gratis asseritur, gratis negatur.
-
- Posts: 987
- Joined: Fri Jun 01, 2012 6:17 pm
Re: Happy Days in Random Chatter 10
Dominant/recessive doesn't necessarily correlate to frequency. If the majority of the population is recessive, than most people are going to procreate with other recessive people. For instance, you see a lot of blond hair and blue eyes in Scandinavian countries, even though those are recessive.Digit wrote:Interesting, in this list of human traits with simple inheritance patterns, I would have thought smooth chin was dominant and cleft chin recessive, since I rarely see people with cleft chins. I suppose that list is a gold mine of "what are you?" discussion.
Re: Happy Days in Random Chatter 10
OK, so it is dominant = at least one, you get X and recessive = you need both to get X. Interesting that polydactyly is dominant.
Quod gratis asseritur, gratis negatur.
Re: Happy Days in Random Chatter 10
Dwarfism is on the dominant side of that list, but I know I've seen dwarf parents (at least one of the parents) with normal-height kids. I guess there are different kinds of dwarfism, or that list isn't exactly right.
*D'oh. I always get it wrong. Of course a parent with a dominant trait would express it but could pass a recessive by chance to their child (assuming they're not homozygous). I've never seen two normal-height parents give birth to a child with dwarfism. The real inconsistency would be two recessive parents with a child with a dominant trait.
*D'oh. I always get it wrong. Of course a parent with a dominant trait would express it but could pass a recessive by chance to their child (assuming they're not homozygous). I've never seen two normal-height parents give birth to a child with dwarfism. The real inconsistency would be two recessive parents with a child with a dominant trait.
Quod gratis asseritur, gratis negatur.
Re: Happy Days in Random Chatter 10
People with achondroplasia (the most common kind of genetic dwarfism) are heterozygous dominant for the gene, which means that they have one gene for dwarfism (D) and one gene for average height (d). Since dwarfism is dominant, anyone with genotype Dd will be a little person. However, if two Dd parents have children, their children have a one in four chance of being genotype dd, which would make them average height. (They also have a one in four chance of conceiving a fetuses with genotype DD, but those fetuses are nonviable, which is how you know that any child or adult with dwarfism is Dd.)Digit wrote:Dwarfism is on the dominant side of that list, but I know I've seen dwarf parents (at least one of the parents) with normal-height kids. I guess there are different kinds of dwarfism, or that list isn't exactly right.
Incidentally, average height parents can also have children with genetic dwarfism if there's a sporadic mutation in that gene when the child is conceived.
Re: Happy Days in Random Chatter 10
I should have said "little person" instead of "dwarf" as the noun form of a person with that condition, according to mainstream sensitivities, shouldn't I?
Quod gratis asseritur, gratis negatur.
Re: Happy Days in Random Chatter 10
I believe so. I have a friend whose son has dwarfism, so I'm trying to be more aware of the preferred terminology (and that's also why I knew the answer to your question off the top of my head), but when it comes to P.C. terminology, in general, I figure just do your best, and be open to learning better ways of communicating what you want to say.Digit wrote:I should have said "little person" instead of "dwarf" as the noun form of a person with that condition, according to mainstream sensitivities, shouldn't I?
Re: Happy Days in Random Chatter 10
Yeah, that table is definitely not clear enough for my tastes. For instance, I cannot roll or curl my tongue, but everyone else in my family - half-siblings, mother - can. So clearly I did not get some copy of some gene that they did, but does that mean I am simply rr where they are Rr?Or are there epigenetic factors at work? Is this a single-gene trait?
I also have Morton's Toe - do both parents have to express the trait, or could they both be heterozygous?
When I first met my boyfriend, we were discussing his cousins' rather striking hair colors. (Anyone with a cursory familiarity with Divine Comedy or Studio C can draw their own conclusions.) He was like, "well, since red hair is a recessive trait..." I was like, "oh? indeed? you've unlocked the code to hair color heredity that has baffled geneticists for centuries? you know all the pigments present in human hair and all the gene loci? Please, share your research." Sarcastic but effective. :P
I also have Morton's Toe - do both parents have to express the trait, or could they both be heterozygous?
When I first met my boyfriend, we were discussing his cousins' rather striking hair colors. (Anyone with a cursory familiarity with Divine Comedy or Studio C can draw their own conclusions.) He was like, "well, since red hair is a recessive trait..." I was like, "oh? indeed? you've unlocked the code to hair color heredity that has baffled geneticists for centuries? you know all the pigments present in human hair and all the gene loci? Please, share your research." Sarcastic but effective. :P
Re: Happy Days in Random Chatter 10
I can roll my tongue into a basic 'u' and flip it almost upside down, but I can't do any of the fancy tricks as in this image (I'm not even sure exactly what the bottom-left one is).
Quod gratis asseritur, gratis negatur.
Re: Happy Days in Random Chatter 10
I can do the bottom-right one!Digit wrote:I can roll my tongue into a basic 'u' and flip it almost upside down, but I can't do any of the fancy tricks as in this image (I'm not even sure exactly what the bottom-left one is).
Re: Happy Days in Random Chatter 10
I guess I'm just a cloverleaf tongue level 1.
Quod gratis asseritur, gratis negatur.
Re: Genetic Things
Gosh, can't you guys keep off topic.
Re: Happy Days in Random Chatter 10
to be fair, it is recessive, but it's not as simple as other traits http://en.wikipedia.org/wiki/Red_hair#GeneticsPortia wrote:When I first met my boyfriend, we were discussing his cousins' rather striking hair colors. (Anyone with a cursory familiarity with Divine Comedy or Studio C can draw their own conclusions.) He was like, "well, since red hair is a recessive trait..." I was like, "oh? indeed? you've unlocked the code to hair color heredity that has baffled geneticists for centuries? you know all the pigments present in human hair and all the gene loci? Please, share your research." Sarcastic but effective.
Re: Happy Days in Random Chatter 10
I'm guessing they're just rolling their tongue into a "U" on the bottom left. What's going on in top right though? They somehow made their tongue into an ear shape?Digit wrote:I can roll my tongue into a basic 'u' and flip it almost upside down, but I can't do any of the fancy tricks as in this image (I'm not even sure exactly what the bottom-left one is).
Re: Happy Days in Random Chatter 10
That was a surprisingly solid Wikipedia article.Whistler wrote:to be fair, it is recessive, but it's not as simple as other traits :-) http://en.wikipedia.org/wiki/Red_hair#GeneticsPortia wrote:When I first met my boyfriend, we were discussing his cousins' rather striking hair colors. (Anyone with a cursory familiarity with Divine Comedy or Studio C can draw their own conclusions.) He was like, "well, since red hair is a recessive trait..." I was like, "oh? indeed? you've unlocked the code to hair color heredity that has baffled geneticists for centuries? you know all the pigments present in human hair and all the gene loci? Please, share your research." Sarcastic but effective. :P