xerath supp>xerath mid? =]
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Hi, I am a first-year biology teacher beginning my unit on Mendelian genetics. I have no questions about the concepts, they are pretty straightforward. However, I am having difficulty finding easy-to-understand examples of codominance and incomplete dominance relevant to urban students (majority black and Hispanic). When I investigate common ones that I know from high school, such as wavy hair, I cannot find any trustworthy, scientific sources that actually confirm that wavy hair is caused by incomplete dominance. In fact, many classic human examples (e.g. ear lobes) have not shown up in any trustworthy sources. The reliable lists of codominance and incomplete dominance in humans are very small.
I want to use real examples with my students, rather than made-up genes, when possible. So I have a couple of questions:
- What gene, if any, causes wavy hair in heterozygotes (vs straight or curly hair)?
- Is the above specific to people of European descent, or is it applicable to people of African descent too? Natural black hair seems to be classified separately from curly hair.
- Are there any other examples of incomplete dominance or codominance in physical human traits? Blood type and sickle cell anemia aren't as tangible as I would like...
- Am I crazy??? Or are those classic "dinner table genetics" examples like hair texture or ear lobes not scientifically supported?
Thank you!
So we know that genetics works differently in Asoiaf. That certain traits that would normally be dominant and are not and that certain blood is stronger as opposed to said traits. So far we know
Tully>Stark
Stark>Targaryen
Targaryen=Martell seem fairly equal based on Rhaeger and Elia's children
Baratheon > most other houses
One we can possibly consider
Whent>Arryn (Based on Robin's coloring. He inherited neither the Tully or the Arryn traits but I do not believe the "Littlefinger explanation. Lysa would have harped on that in her rant)
What about the other houses? Where would they rank and who is the strongest? And why?
House Baratheon has got to have the strongest seed, right? It was a major plot point, the black hair and blue eyes are so reliable they can be used to help identify bastards among the smallfolk.
House Lannister must be weaker than the Baratheons. The last time a marriage was recorded between the stag and lion, the child had black hair.
House Tully is probably stronger than House Stark. Of Ned and Cat’s five children, only Arya has the Stark coloring.
House Tully is also probably stronger than House Arryn. Harry the Heir is supposed to have the look of a young Jon Arryn, and his hair is sandy blond and he has deep blue eyes. Sweetrobin has brown hair which isn’t Tully auburn, but it’s closer than blond. And he has Lysa’s pale and watery eyes.
House Targaryen is probably the weakest? The blood of House Martell won out over Rhaegar’s in Rhaenys’ coloring. And Lyanna Stark’s blood won out over his as well.
I’m not sure about the Tyrells or Greyjoys.
Tentative rankings based on the discussion so far: (will update as more examples are given)
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Baratheon (every true child of this line has had the black hair and blue eyes; there is only one known exception † which involves three consecutive generations of Velaryon and Targaryen marriage and intensive inbreeding to fully eradicate the Baratheon traits)
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Tully (four out of five Stark kids favor Cat)
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Stark (Jon Snow takes after Lyanna)
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Arryn (Sweetrobin favors Lysa)
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Martell (tie with Targaryen because of Rhaenys & Aegon; also brothers Baelor Breakspear and Maekar I)
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Targaryen (tie with Martell because of Rhaenys & Aegon; also brothers Baelor Breakspear and Maekar I)
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Lannister (Genna Lannister’s Frey sons do not have the gold hair and green eyes. And the child from a distant Lannister-Baratheon union was black-haired.)
Tyrell and Greyjoy still unknown. Within the Reach however, Tyrell blood has proven stronger than that of Houses Hightower and Redwyne, as Margaery and her siblings still retain the curly brown hair and brown eyes typical of that house.
† Laena and Laenor Velaryon who probably had over 70% Valyrian blood. Their mother, Rhaenys, had at least 65% Valyrian blood, and exhibited the purple eyes but retained her mother Jocelyn Baratheon’s black hair.
Let's say among blue eyes and black eyes, black eyes is the dominant trait. Will that still be true in a different country/continent?
In a heterozygote, the dominant allele will be expressed in preference to the recessive allele. How does this work biochemically in the cell? Would it be that only the dominant allele is transcribed, or simply that the dominant allele is transcribed more than the recessive allele?
Additionally, after reading about X-inactivation, I am confused as to how this process can exist alongside sex-linked diseases. For instance, if I understand correctly, the gene for Hemophilia is located on the X-chromosome, and because females have two X chromosomes, the existence of a recessive disease-causing allele on one X-chromosome can be masked by the existence of a dominant allele on the other X-chromosome. However, if X-inactivation is a random process, then wouldn't some cells end up expressing the recessive allele while others end up expressing the dominant allele? What effect would this have on the organism as a whole, in terms of the pathology of Hemophilia and other sex-linked diseases?
Thank you! I'm not confident as to whether I understand these concepts correctly, so it would be great if someone could correct me if I'm wrong.
CONTEXT: So the premise of my world is a not-too-far-flung future on a terraformed Venus where there is a slave race [Rose Champagnes, aka Roscha/Roska depending on dialect], who are genetically engineered humans spliced with an alien micro-organism found on Venus called Slosh.
Slosh makes them forever young [until they most likely die of cancer] and gives them a rose-gold tint due to induced production of pheomelanin. The entire thing is heavily inspired by this Kurzgesagt video except I'm taking the creative liberty to speed up the process so it only takes like 300 years instead of 3,000. I can explain more about Slosh if anyone wants to know.
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Onto the point of the post. Considering that I don't want this Venusian planet-wide society to be devoid of known social issues, and the use of genetic engineering, I thought it obvious that genetic engineering is going to try to be used to get rid of disabilities, especially neurodivergences like Autism which is currently under threats like the use of prenatal testing. In Venusian society, they would likely try to locate the genes that turn Autism "on" and remove them.
As I don't want autism and various other neurodivergences and disabilities to disappear from my worldbuild (and such ableism to disappear as well) I was thinking of adding in biological consequences for attempting to remove these conditions from the gene pool. This is where I need the help of anyone who is taking the time to read this. I'm trying to make consequences that make biological "sense" if you know what I mean.
But I don't know if it's playing into stereotypes of the "autistic savant" by saying deleting autism severely damages passion, commitment, using patterns to make intellectual connections, and thinking outside of the box. I'm not diagnosed with autism [do want to get tested at some point] and I don't know where I'd be overstepping, or even if this whole thing is stupid.
I think it would work with ADHD [which I have] in that getting rid of it would damage the ability to make deep connections with others quickly, which is important if you're part of some space military and need to bond with your squad fast. It would also damage the ability to fall into flow, damage creativity, and probably also a lot of things that would overlap with autism like becoming passionate.
My entire idea is that these disabilities cause their own innate iss
... keep reading on reddit ➡)