Can someone become his own grandpa?

Answer 1

No it is not possible because even if you did marry your grandmother your parents were born before you and you did not have them so they could have you.

AnswerYou could be your parents step-parent. ANSWER:Well

First you would have to marry a widow who has a grown up daughter. Your father then marries the daughter, which makes your dad your son-in-law. Then your daughter is your mother because she is your father's wife. Then you and your wife, the widow, have a son, who then becames a brother-in-law to Dad, and so becomes your uncle.

That means that if he is your uncle, then that also made him brother of the widow's grown-up daughter who is also your stepmother. Then Father's wife has a son who therefore becomes your grandchild, for he is your daughter's son. Your wife is now your mother's mother and althogh she is your wife, she's your grandmother too. So if your wife is your grandmother, then you are her grandchild. And as husband of your grandmother, you are your own grandpa!!!

- Taken from the song "I'm My Own Grandpa" by Guy Lombardo and rephrased into paragraph form

Step-step-GrandpaIn the above answer, you are not your own grandpa, but your own STEP grandpa (actually, you are your own Step Step Grandpa, since you are the Step Father of your Step Mother). However, you could have stopped after the two marriages - no further kids are necessary, unless you're a song writer trying to stretch this whole scenario into a full-length song. For that matter, you need not involve your father or some young chick for him to marry. You just marry your own natural grandmother, and then you will be your own Step-Grandfather (just one "step"). Time Travel(Note, to make the following discussion simpler, I'm assuming that you're talking about becoming your own PATERNAL grandfather - your father's father - though the logic works just as well for a MATERNAL grandfather.)

To TRULY become your own grandpa, you would have to travel back in time, to 9 months before your father was born, and have sex with your grandmother. But I seriously doubt this would work. Presumably, your ORIGINAL grandpa was not you, but someone else. His sperm provided half of the genetic material in your father's chromosomes. If the sperm provided by your original grandpa was replaced with YOURS, your father would likely be a very different person (let's call him dad.2). It is extremely unlikely that he would still meet and marry the same woman (your mother), and therefore, even if the two of them still had a kid (which is not a given), three fourths of your genetic material (the half provided by your mother, plus half of your father's half) would be different than it is. For all practical purposes, "you" would not be the same person you are now. Even if your father still met and married the same woman, one fourth of your genetic material would be altered, and you still would not be the same person you are now.

This could lead to a serious paradox. You see, it is almost certain that your personality and life circumstances would be altered so dramatically that you never get in that time machine and go back to have sex with your grandmother. Then, your original grandfather would be restored as your actual grandfather, but then the "you" that emerged two generations later would be the original you and would still go back in time and have sex with your grandmother. Can you see the never-ending cycle that is now emerging?

On the other hand, maybe you, even in your genetically-altered state, still go back in time and have sex with your grandmother. This is still a paradox, and it is still a never-ending cycle, but the cycle doesn't just repeat itself, verbatim, every other pass like it does in the previous example. The genetically-altered you (the one that has you as a grandfather - we'll call him you.2) will replace you.1 as your father's father, further altering your father's genetic material (dad.3), and further altering your OWN genetic material (you.3). Assuming you.n continues to go back in time and have sex with your own grandmother, it will lead to an infinite series of you.n's, each one genetically different from the rest.

On second thought, there won't be an infinite number of different you.n's. Though there are a whole lot of different possible genetic makeups, it is not an infinite number. Eventually, after maybe something like 102,000,000 iterations, you.n would be genetically identical to the original you.1. So there would not be an infinite number of different you.n's. But you would still continue to go back and have sex with your grandmother, and the cycle, however long it already is, would still continue. So I guess the series is infinite, and there is still an infinite number of you'n's, but they will not all be different, genetically.

But there's also the problem of inbreeding. Any time you have multiple generations of inbreeding, it eventually results in serious handicaps, including mental retardation and sterility. If one you.n after another keeps going back in time and impregnating grandma, your grandmother's genes will become highly concentrated in your father. Eventually, dad.n will be unable to breed. And you.n will never be born. The cycle would stop there, and no "you", of any version, would ever be born. But then you wouldn't have gone back and knocked up grandma, while your original grandfather would have, which means you would still be born. Which means ... oh, this is giving me a headache.

Then there's a practical matter. When you.2 goes back to have sex with your grandmother, assuming he did everything exactly like you.1 did, he would arrive at the same time and place as you.1. The two could appear at exactly the same moment in exactly the same place. That can't be good. Or maybe they don't arrive at exactly the same place. But they'll presumably be pretty close in both place and time. And they'll both be pursuing a sexual encounter with the same woman, so they'll eventually run into each other anyway. Who wins that competition? Does it get ugly? Is one or both of them killed? While they're pre-occupied fighting each other, does the original grandfather go ahead and have sex with his wife? Assuming you.2 wins the fight, in time to still have sex with grandma, then there's going to be a you.3 thrown in the mix, and now there are 3 you.n's all vying for the honor of having sex with grandma. And assuming you.3 wins that fight, there's a you.4, and on and on and on. How many you.n's will be around trying to have sex with grandma? Or does each you.n peacefully yield to you.n+1? And how the heck do they all know which one is the LATEST you.n? Time travel can be sooo confusing.

Then there's the "branched timeline" theory of time travel. In this paradigm, if someone goes back in time and changes something, it immediately causes the timeline to split. In one branch, history plays itself out the same way it always did (in this case, with your original grandfather remaining your grandfather). The other branch is where the "change" occurs. In that branch, you become the father of your grandmother's child (though that child will not the be same person you know as your father, because his genes will be very different). 20-30 years later, that child might have a child of his own, but it certainly won't be you! In this scenario, you are not your own grandfather, because the timeline in which you impregnated your grandmother is not the same timeline in which you were born to your grandmother's son. In one timeline, you're the grandfather; in the other timeline, you're the grandson. But in neither are you both grandfather and grandson.

There's another theory of time travel that goes something like this. There is only one timeline, immutable and unchangeable. Time travellers or no time travellers, whatever happened in the past, happened, and it can't be changed. If time travellers go back and "change" something in the past, it's not really a "change" at all, because it always happened exactly that way. So, for the case at hand, if you really do go back and have sex with Grandma, then it was already pre-ordained that you do so, and by doing so, you are merely fulfilling your own destiny, not "changing" history.

Make sense? Not when you look at genetics again. If you are your own grandpa, then you neccessarily have the exact same genetic make-up as your grandfather (yourself). In other words, after crossing your genes with your grandmother's to create your father's genes, and your father crossing his genes with your mother's, the genes of this second generation offspring would be IDENTICAL to yours. The odds against this happening are astonomical. In fact, I believe that, for most of the possible human genotypes, it is simply impossible (I don't mean so small a chance as to be "practically impossible", I mean downright, absolutely, no holds-barred, physically IMPOSSIBLE) for a grandfather and his grandson to share the exact same genotype.

I'll use just one gene as an example - the A/B/O blood type gene (ignoring the Rh part of the blood type, which is on another gene). Let's say you are blood type AB and your grandmother is O. Your two A/B/O alleles are A and B. Your grandmother's are both Os. Your father (the offspring of you and your grandmother) would necessarily be either blood type A or blood type B, though in both cases, there is a recessive (not expressed) O allele. Now, let's say your mother is type O. Whether your father is type A or B, there is absolutely no combination of his genes and your mother's that can result in a child with blood type AB. That is your blood type, as we established in the set-up. But it is impossible for you to have that blood type. This is what I would call a "genetic paradox".

Now, I admit that blood type AB is decidedly rare, and in all likelihood, you and your grandmother would not be faced with such a genetic paradox when attempting to mate, at least not with that particular gene. But keep in mind that the human body has tens of thousands of genes. Though there might be a very small chance that any ONE such gene would result in a genetic paradox when yours and your grandmother's were matched up, it is a near certainty that, with the large number of genes involved, there is at least one gene that would cause a problem. In fact, it would have to be very rare combination of your genes, your grandmother's genes, and your mother's genes that would not result in such a genetic paradox.

ActuallyI stopped reading the above answer because: Going back in time and inseminating your grandmother and successfully becoming your own grandfather will not change a thing. It already happened! Your father was always your son, even though your grandfather is still someone else; he is not biologically related to you. You don't have to be married to someone to get them pregnant. Therefore it is entirely possible to become your own grandfather if, indeed, time travel is entirely possible. Time Travel, revisitedThe person who posted the "Actually" contribution should have finished reading the previous "Time Travel" contribution. "It already happened" is just one theory regarding the effect of changes made by time travellers on the present. And a very poor theory at that. But even if it were the "correct" theory, it is still very improbable (if not impossible) for someone to become his own grandfather.

Before I proceed, let me make something absolutely clear. By "grandfather", I mean, and have always meant, one's biological grandfather. So arguments about the guy you call grandpa, because he's married to grandma and is believed (falsely, in this case) to be your biological grandfather, are irrelevant.

Now, to proceed. Under the "it already happened" time travel paradigm, if you are your own grandfather, then you have exactly the same set of genetic material as your grandfather had. In other words, after crossing with your grandmother's genes to produce your father, then crossing again with your mother's genes to produce you, the genes end up EXACTLY the way they were in your grandfather's cells.

There are over 20,000 genes in the human genome. Even if 90% of them are identical for all humans, that leaves 2,000 genes that vary between humans. Each of these genes has at least two possible alleles, which, considering that genes are paired, results in four different possible combinations of alleles. The total number of human genotypes, therefore, is something larger than 4 to the power of 2000, or approximately 1.32 x 101204. That's 13200 followed by 1200 zeroes. That's a trillion, multiplied by itself 100 times. That's a very large number. That's how many possible genotypes a human can have. And the possibility that any two individuals would have the same genotype is the inverse of that number, expressed as a zero, followed by a decimal point, then 1,203 more zeroes before the first significant digit.

Furthermore, depending on the grandfather's, grandmother's, and mother's genotypes, it may be completely impossible, regardless of probability, to duplicate the grandfather's genotype in two generations. Go back and read the blood type example in the earlier "Time Travel" post. Though ABO blood type is just one gene, and you most likely don't have to worry about that one specific gene screwing up the works, there are 1,999 more genes where a similar situation could occur. And it only has to occur in ONE of those genes to make it completely impossible for a grandfather and a grandson to have the same genotype. In fact, out of all the possible scenarios involving the grandfather's, grandmother's, and mother's genotypes for a given simple, 2-allele gene (assuming both alleles have the same frequency), there's an 18.75% chance of impossibility, FOR EACH GENE, which leaves a 81.25% chance that, for the given gene, everything works out ok. But that's just one gene. You have 1,999 more of them to consider. Statistically, you would raise this 0.8125 chance to the power of 2000. This results in 4.43 x 10-181, which can be expressed as a zero, followed by a decimal point, then 180 zeroes, then the digits 443. So you see, there is a very small chance that the grandfather's, grandmother's, and mother's genotypes will even result in a possibility that the grandson will have the same genotype. And when it exists, even that possibility is a very, very small one.

It is possible!Using real science (albeit not perfected yet) you can become your own grandfather! All you need to do is transfer a nucleus from one of your cells into an egg with no nucleus (preferably one of your daughter's for thoroughness) and transfer that egg into your daughter's uterus. Nine months later you are born as your grandson. Congratulations! No, it's not!(At least not like in the answer above)

In the above answer (which essentially involves cloning), you will have a "grandson" who is genetically identical to yourself. While that is a minimum requirement, it does not result in you actually BEING your own grandfather. There is only one you. And despite the fact that your "grandson" is genetically identical to you, he is NOT you. Identical twins are called such because they are genetically identical. Yet they are not "the same person". QED.

For that matter, that child is not really your grandson, since he was not conceived in the way that a "son" is conceived, by definition. He's just a clone. The fact that your daughter's egg was used is irrelevant, since her own genetic material played no part in the clone's genetotype.

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It also isn't possible because in order to be your grandpa you would have to have your kids and his/her spouse have the exact same DNA that you had and then your grandson would go back in time (who he is you.)

You Bet your time traveling butt it is possible (although highly improbable)

You have a bunch of genes, some from dad and some from mom, You have a 50% chance of passing on each of your dads genes and 50% chance of passing on each of your moms Genes.

You travel back in time and combine genes with your grandmother. Your child (your dad) has half of your genes and half of his moms genes.

If you pass on only the genes you got from your dad and non from your mom, and then your son (who is your dad) does the same to you.

Since you and your father are both only conceived once, there is none of this you.n paradox nonsense.

Tada, you are your own grandfather.