That could be interesting - maybe the woman wants to give the clone the kind of childhood the woman herself wanted.
Twins and clones
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By "DNA," do you mean a cloned embryo? If so, I'm confused as to why implantation into a (related) surrogate would come across as wrong or be off-putting. Similar non-clone, but related procedures are done currently. For example, a grandmother can carry an embryo transplanted from her daughter (or with other family members being surrogates). In the clone case, it would be having the mother carry a copy of her original child. I'm confused as to why that would be wrong or off-putting. Then again, maybe I am misunderstanding your meaning.
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As before, think of it however you want, but biologically, I don't think it's blurred or open to interpretation really.
If, using current technology (not that we don't have the technology to clone humans, but no one has fessed up yet [I suspect there are probably clones out there that someone is going to reveal at some point -- like from Chinese labs, not some sci-fi thing]) someone used IVF and one of the fertilized eggs split. If they implanted one of those embryos, and then years later implanted the other, would those be siblings? I feel like you'd say yes because the same person gestated them. What if two different surrogates gestated them? What if one was gestated by the embryos' grandmother and one by an aunt?
I'm not trying to be argumentative, trying to understand how you're drawing the lines, because it's completely non-intuitive to me.
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Cousins are children of siblings. If a second child is produced (from the surrogate aunt and her brother-in-law's contribution), the child (in theory) is both a half-sibling and a cousin to the child of the brother-in-law and his wife. There is direct, genetic similarity between both children of the brother-in-law. Biologically, they are half-siblings. Socially, the father-in-law's children can be deemed cousins to one another (depending on who you ask) as well.
For me, an author would have to explain both biological and social elements (and not just one) to, perhaps, satisfy a broad readership. Even then, it might be off-putting for some readers (if explained abrasively). My views are my own. I think our side discussion focused on my views (more than needed) and, as a result, has hijacked the thread -- at least to some degree -- from the OP's request. I don't know if the OP got the information requested or not, so this may be my final post.
OP: As AW Admin suggested, biological and social issues sounds like a great way to work through the familial relationships (whether or not anything I added was useful to you). Good luck. It sounds like a challenging topic to address (for a broad readership).
I'm gonna hide on the shadows of my own thread and be slightly bewildered by the whole argument, if that's alright 
The set up is for a fantasy book where a race who have specific fertility problems (for complicated reasons) and reproduce almost entirely through invitro fertilisation.
Added into that mix are a pair of MCs who are clones of a specific set of fraternal twins, and basically I was trying to work out, in social AND biological terms, whether they still count as siblings, and would still share a sibling bond. They are genetically related, in the way that their "original" clone-parents are, and would share a surrogate womb together, so hopefully that's still believable as a bond.
The set up is for a fantasy book where a race who have specific fertility problems (for complicated reasons) and reproduce almost entirely through invitro fertilisation.
Added into that mix are a pair of MCs who are clones of a specific set of fraternal twins, and basically I was trying to work out, in social AND biological terms, whether they still count as siblings, and would still share a sibling bond. They are genetically related, in the way that their "original" clone-parents are, and would share a surrogate womb together, so hopefully that's still believable as a bond.
I'm gonna hide on the shadows of my own thread and be slightly bewildered by the whole argument, if that's alright
The set up is for a fantasy book where a race who have specific fertility problems (for complicated reasons) and reproduce almost entirely through invitro fertilisation.
Added into that mix are a pair of MCs who are clones of a specific set of fraternal twins, and basically I was trying to work out, in social AND biological terms, whether they still count as siblings, and would still share a sibling bond. They are genetically related, in the way that their "original" clone-parents are, and would share a surrogate womb together, so hopefully that's still believable as a bond.
To me, that sounds entirely believable for a sibling bond. You have the non-subjective biological relationship — they share 50% of their DNA, same as the original fraternal twins — and you have the social aspect if they are raised together. You even have the shared gestation in the womb.
My father was an identical twin. My uncle’s children are genetically my half-siblings, since we share 25% of our DNA, but socially my cousins. My step-siblings are not my biological siblings, but are certainly my social siblings.
My daughter and my sister’s adopted daughter are social cousins, but not biological ones.
Social and biological definitions are not in conflict. They’re just different. It doesn’t seem confusing at all — to me, anyway — if you define your terms and are clear about the framework you are using to describe the relationship. And it seems to me you have both going for you in your scenario.
Genes are fun. You are as related to your full siblings as you are to your father and mother, since you share 50% DNA with each. I also like that you can be more (genetically) related to one grandparent, depending on how your recombination plays out.
I want to add that someone you are raised with from birth or toddlerhood can be considered a sibling, emotionally, even if you are not related. My foster sister is my real sister. I came to that realization a few years ago. Whereas my blood sister, who is a lot older, and was an accepted member of the family, is, emotionally, a distant, unloved, relative. I speak of the two now as "sister" and "crazy older sister" to differentiate them.
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Yes, a totally fair point, Cobalt. However, in this particular case, where all the children are raised communally without knowing their parents (in the style of Plato's Republic), it's quite possible that any of your friends might also be a sibling biologically. T
hat sort of means that the only bonds which are meant to exist, are the ones you make yourself. The set up is designed to encourage found families, in a sense, and to dissolve most bonds made on the basis of biological ties.
I hope that doesn't sound jumbled lol.
hat sort of means that the only bonds which are meant to exist, are the ones you make yourself. The set up is designed to encourage found families, in a sense, and to dissolve most bonds made on the basis of biological ties.
I hope that doesn't sound jumbled lol.
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What do you mean by "sibling bond"? Siblings don't need to be biologically related at all to share a sibling bond, IMO.
Personally, the correct biological terminology isn't so important to me in most contexts except insofar as it may have biological consequences.
Unless I'm literally in a biology seminar, I typically assume people are using terms like "parent", "sibling", "cousin", etc., with their social connotation rather than their biological definition. That's how I would interpret them as a reader unless in the context specifically implies otherwise.
I refer to a lot of people as "cousin" and "sister" who I may not be biologically related at all.
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All that sounds fine to me. The primary importance of recognizing biological relationships in that context would be knowing when you're too genetically similar to safely reproduce.
Okies Though j ahould explain that in this case that isn't issue--incest is safe for their race.
By sibling bond, I mean in a society that officially recognises everyone of a certain age as legally/philosophically "siblings" (because almost no one has any parents or nuclear family), I sort of wanted something which went against that--a wholly irrational (from society's point of view) attachment based on biology.
But then I got myself caught in this tailspin of overanalysing from genetics from every angle and... this thread was born!
Though j ahould explain that in this case that isn't issue--incest is safe for their race. By sibling bond, I mean in a society that officially recognises everyone of a certain age as legally/philosophically "siblings" (because almost no one has any parents or nuclear family), I sort of wanted something which went against that--a wholly irrational (from society's point of view) attachment based on biology.
But then I got myself caught in this tailspin of overanalysing from genetics from every angle and... this thread was born!
To me, that sounds entirely believable for a sibling bond. You have the non-subjective biological relationship — they share 50% of their DNA, same as the original fraternal twins — and you have the social aspect if they are raised together. You even have the shared gestation in the womb.
My father was an identical twin. My uncle’s children are genetically my half-siblings, since we share 25% of our DNA, but socially my cousins. My step-siblings are not my biological siblings, but are certainly my social siblings.
My daughter and my sister’s adopted daughter are social cousins, but not biological ones.
Social and biological definitions are not in conflict. They’re just different. It doesn’t seem confusing at all — to me, anyway — if you define your terms and are clear about the framework you are using to describe the relationship. And it seems to me you have both going for you in your scenario.
Genes are fun. You are as related to your full siblings as you are to your father and mother, since you share 50% DNA with each. I also like that you can be more (genetically) related to one grandparent, depending on how your recombination plays out.
It’s not quite that simple though.
While a child will always share 50% of its genome to each of their parents, siblings only share 50% with each other on average. They can actually share anywhere between 0 and 100%, with 50 being the mean. This is because each gamete (sperm/egg) takes a random chromosome from each pair.
Those percentages get trickier for cousins etc. as it’s all based on average values.
Of course identical twins take the chance out of the equation
It’s not quite that simple though.
While a child will always share 50% of its genome to each of their parents, siblings only share 50% with each other on average. They can actually share anywhere between 0 and 100%, with 50 being the mean. This is because each gamete (sperm/egg) takes a random chromosome from each pair.
Those percentages get trickier for cousins etc. as it’s all based on average values.
Of course identical twins take the chance out of the equation
Caught me simplifying for my example.
You're right, of course, and that explains the luck of the recombinant draw for inheritance from the grandparents. It’s fascinating stuff.
Two first cousins of mine, sisters, are on 23andme along with me. One I share 8.89 DNA with, the other 10.1. This disparity is interesting but I can't account for it.
That doesn't seem unusual to me. The one who shares less DNA probably got more from the parent who is not a blood relative of yours.
Also, DNA can "wash out" through successive generations and even be lost altogether.
Except when the DNA chains combine when egg and sperm meet, it's supposed to be 50/50 from both parents... I think...
Probably my non-blood uncle had some genetic material in him from far back that was also in my dad or mom, and that accounts for the one cousin's higher score.
Probably my non-blood uncle had some genetic material in him from far back that was also in my dad or mom, and that accounts for the one cousin's higher score.
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Yeah, it's basically 50-50 but it's not the SAME 50-50 in each sibling. If it were, we'd all be identical (like identical twins) to all our siblings. We're not because aside from the vagaries of gene expression, there are different genes passed down from your parents. So unless your parents are each one of a set of identical twins who married identical twins, your cousins won't turn up with the same percentages because the genes each sibling inherits differ slightly.
Like... if your grandfather passed A-G-G-T to one kid (this makes no sense but just as an example) in that order, and A-G-T-T to the next, and those two kids are your parent and uncle, and you got G-T from your parent but your cousin got T-T, you've got more of a difference than you do from the cousin who got G-T. In addition, because humans are humans, if you've got the same gene from your mother and your father, that will affect what percentages show up in those tests when comparing you to relatives. If you want to track lineage, generally mitochondrial remains unchanged, but if you're testing percentages of entire genomes that are similar, you're going to get differences among different people even with the same relationships.
Hopefully that made sense and is generally correct. Ask Roxxsmom!
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Genetically, they would be full siblings.
Twin is a word we usually use when two individuals are born to the same mom at the same time, whether they be fraternal or identical.
So if the clones of each fraternal twin were gestated to term at the same time by the same woman, then they'd be fraternal twins. Otherwise, we'd call them siblings. Likewise, if clones of two siblings who weren't twins are implanted into the same woman at the same time (and are both carried to term), they could be considered fraternal twins, even if their clone parents weren't born at the same time.
There is no difference genetically between fraternal twins and siblings born to the same woman from different pregnancies. They share, on average, 50% of their DNA. Naturally occurring fraternal twins could even have different dads (and be half siblings) and only share about 25%.
Of course, the social definition of siblings is different and can refer to two or more children raised by the same parents in the same household, even if they are not genetically related (say they are adopted or result of embryo donation or something).
In a futuristic society, though, if artificial means of conception and gestation become commonplace, our definitions of these things could shift.
It’s not quite that simple though.
While a child will always share 50% of its genome to each of their parents, siblings only share 50% with each other on average. They can actually share anywhere between 0 and 100%, with 50 being the mean. This is because each gamete (sperm/egg) takes a random chromosome from each pair.
Those percentages get trickier for cousins etc. as it’s all based on average values.
Of course identical twins take the chance out of the equation
This is correct, though the odds of sharing 100% of your DNA with a full sibling who is not an identical twin, or 0% of your DNA with a full sibling is so astronomically small that it's not really worth considering.
The distribution for the amount of DNA shared by full siblings clustersclose to the 50% mark with humans.
It would be less for a fruit fly or another species with a small number of chromosomes, of course.
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Consider this another way of looking at what has already been said.
Meiosis is the process where the cell's genes divide up into strands of recombined genes of the parent.
What that means is the parent's DNA containing their two parent's genes doesn't just split in two the way it does in normal cell division (mitosis). Instead as the egg and sperm cells are formed with only half of each parent's DNA, the cells don't end up with copies of each side of the parents' DNA strands, they end up with genes mixed from the two sides of the strand.
Think of two decks of card, red and blue being each side of a DNA strand. When cells divide the DNA strand splits apart and a new copy is made from each side, the same red and blue sides. Then the cell divides with the new DNA dividing along with the cell. You end up with two cells with the same DNA strand in each. That's mitosis.
In meiosis when a sperm and egg are formed with only one half of the parent DNA strand, instead of one deck going into egg1 and one deck going into egg2, the decks are shuffled, then divided in half with all the right cards, but now the red and blue decks are shuffled before they are cut.
That is how one gets half one's DNA from one parent and half from the other, but each half is a shuffled mix of that parent's DNA, not simply the same half as the siblings got.
Meiosis is the process where the cell's genes divide up into strands of recombined genes of the parent.
What that means is the parent's DNA containing their two parent's genes doesn't just split in two the way it does in normal cell division (mitosis). Instead as the egg and sperm cells are formed with only half of each parent's DNA, the cells don't end up with copies of each side of the parents' DNA strands, they end up with genes mixed from the two sides of the strand.
Think of two decks of card, red and blue being each side of a DNA strand. When cells divide the DNA strand splits apart and a new copy is made from each side, the same red and blue sides. Then the cell divides with the new DNA dividing along with the cell. You end up with two cells with the same DNA strand in each. That's mitosis.
In meiosis when a sperm and egg are formed with only one half of the parent DNA strand, instead of one deck going into egg1 and one deck going into egg2, the decks are shuffled, then divided in half with all the right cards, but now the red and blue decks are shuffled before they are cut.
That is how one gets half one's DNA from one parent and half from the other, but each half is a shuffled mix of that parent's DNA, not simply the same half as the siblings got.
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Many thanks all, that is really helpful
Discussion aside, for the specific story in question I went with "fraternal twins cloned themselves to make another pair of fraternal siblings/twins" and I imagine it probably took quite a few tries to get it right. But she's got hundreds of years and a ship's worth of tech. My envisioning is they'll look similar but with somewhat different colouring to the originals (nonhuman race, with a lot of variation in skin colour + patterning).
Socially, they're recognised in general terms as being siblings/twins for having shared a womb in gestation, but since familial ties hold no cultural significance, the connection doesn't mean anything to anyone *except* them and their creator(s).
Discussion aside, for the specific story in question I went with "fraternal twins cloned themselves to make another pair of fraternal siblings/twins" and I imagine it probably took quite a few tries to get it right. But she's got hundreds of years and a ship's worth of tech. My envisioning is they'll look similar but with somewhat different colouring to the originals (nonhuman race, with a lot of variation in skin colour + patterning).
Socially, they're recognised in general terms as being siblings/twins for having shared a womb in gestation, but since familial ties hold no cultural significance, the connection doesn't mean anything to anyone *except* them and their creator(s).
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Another thing to consider is that the odds of a given human producing two identical egg or sperm cells is astronomically small
One chromosome from each pair (humans have 23 pairs) is randomly assorted into each gamete (egg or sperm) that is produced. This makes the odds of the same chromosomes being sorted into each gamete is 1 out of 2 to the twenty third power, or 1/8,388,608.
The odds of two identical eggs coming together with two identical sperm is 2^^23 * 2^^23 , or 70,368,744,177,664 (more than 70 trillion) genetically-distinct possible zygotes from a single pair of parents. This is far, far greater than the number of humans who have ever been alive!
And there's also the recombination of genes on chromosome pairs that occurs during early meiosis, before the chromosomes are separated. Chromosomes of each pair line up and swap some segments of their arms. This reduces gene linkage and makes the odds of the same exact combination of genes being sorted into two of the same egg or sperm much, much less.
https://genetics.thetech.org/ask-a-geneticist/odds-making-identical-eggs
Then come the odds of (even with the same two parents) a genetically identical sperm and egg (to a previous fertilization) getting together.
This explains why identical twinning (where the inner cell mass of an early embryo splits) is the only way we can realistically get genetically identical siblings via natural processes.
The children of identical twins are considered first cousins, but they will be as related as half siblings are (since one set of parents are virtually identical genetically). If identical twins marry identical twins, then their children would be as related as full siblings.
These little videos are cute explanations of various biological processes that might be useful to writers who need to grasp some biological concepts for something they are writing. I get some eye rolls from my non majors occasionally, because they're designed for school kids, but they explain things fairly well.
https://www.youtube.com/watch?v=VzDMG7ke69g
The crash courses videos for biology are fun too.
https://www.youtube.com/playlist?list=PL3EED4C1D684D3ADF
One chromosome from each pair (humans have 23 pairs) is randomly assorted into each gamete (egg or sperm) that is produced. This makes the odds of the same chromosomes being sorted into each gamete is 1 out of 2 to the twenty third power, or 1/8,388,608.
The odds of two identical eggs coming together with two identical sperm is 2^^23 * 2^^23 , or 70,368,744,177,664 (more than 70 trillion) genetically-distinct possible zygotes from a single pair of parents. This is far, far greater than the number of humans who have ever been alive!
And there's also the recombination of genes on chromosome pairs that occurs during early meiosis, before the chromosomes are separated. Chromosomes of each pair line up and swap some segments of their arms. This reduces gene linkage and makes the odds of the same exact combination of genes being sorted into two of the same egg or sperm much, much less.
https://genetics.thetech.org/ask-a-geneticist/odds-making-identical-eggs
Then come the odds of (even with the same two parents) a genetically identical sperm and egg (to a previous fertilization) getting together.
This explains why identical twinning (where the inner cell mass of an early embryo splits) is the only way we can realistically get genetically identical siblings via natural processes.
The children of identical twins are considered first cousins, but they will be as related as half siblings are (since one set of parents are virtually identical genetically). If identical twins marry identical twins, then their children would be as related as full siblings.
These little videos are cute explanations of various biological processes that might be useful to writers who need to grasp some biological concepts for something they are writing. I get some eye rolls from my non majors occasionally, because they're designed for school kids, but they explain things fairly well.
https://www.youtube.com/watch?v=VzDMG7ke69g
The crash courses videos for biology are fun too.
https://www.youtube.com/playlist?list=PL3EED4C1D684D3ADF
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