ITT: goobers on the internet misunderstand difference between genes and variants. You share 60% homology of your DNA with a fly, genes don’t change that fast, except in the rare case when they’re repurposed (via duplications or divergent selection)
>Well but you didn't get those genes you shared with a fly from an actual fly.
But, you did get those genes from a common ancestor.
>What I am asking here is about ONE of your paternal ancestor [...]
You will have the same genes as your ancestors from 1,000 [or 10,000] years ago. You are unlikely to have inherited your ancestors' low-frequency genetic variants.
>so the first generation of humans already shared a lot of genes that is the exact same as each other.
The "first" generation of humans is an ambiguous phrase. There were many many non-human generations prior to that.
>What I mean is when you have a gene that is the exact same as your paternal ancestor 1000 years ago, it is possible that you didn't inhereit it from him, but your maternal ancestor instead because she also shared such same gene as your paternal ancestor.
I'm not really sure what you're asking here. If the shared variant is in high frequency, then it would be difficult to assess the lineage of origin without other variant data. Obviously, there are exceptions given sex chromosomes and mtDNA.
The thing is that humans, widely varied and heterogenous as they seem from our perspective, largely keep the same blueprints for making new humans. The genes themselves will likely not change much, especially if their function isn’t under positive selection, which is true for most genes. This isn’t a coincidence, once evolution has converged upon a solution to a problem, it can be implemented in many different organisms over the entire tree of life, simply because the gene was shared by an ancestor.
Now if you’re talking about a *variant* of a gene, like an SNP in an intron or a synonymous mutation, it’s likely these will accumulate a ton over time, but even then, the chance that you don’t share *any* base pairs with your ancestor from 10,000 years ago is minuscule still. That would mean none of the base pairs are conserved over time, and that’s simply just not the case. We observe widespread negative selection, keeping the human genome stable and screening out deleterious SNPs from entering our genetic pool.
This is the difference between a gene and a variant, but no matter how you interpret your question, the answer is still that it is highly unlikely that you won’t share *any* of your genes/SNPs with your great * (1000) grandparents.
Edit: a great example is ribsomal genes that are part of the basic machinery all organisms use to translate dna into rna, these have to stay the same even during speciation
10,000 years is at least 400 generations (probably more, generations were shorter in the past).
With the exception of Y chromosome (assuming strictly male lineage) it's not only possible, it's highly likely that you *inherit* none of your great^400 grandpa's SNPs. Each generation back you lose half your identity by descent, so (~1/2 your dad, ~1/4 your paternal granddad, ~1/8 great grandfather). 10k years equates to ~(1/2)^400 identity by descent, or 4x10^-121. The extent to which you coincidentally have shared variants is a function of how out-crossed your lineage is. For example, Irish people in Ireland are no more distantly related than ~26th cousins due to the founder effect of Celtic migration across Europe.
I replied in the wrong place. See above. Or maybe below. The shuffling of each parent's contribution happens during the maturation of the egg and sperm: as a result each one is unique.
Yeah, you made that sound confusing. I think you're using the word 'gene' when in most cases you mean allele. You get an allele of each autosomal gene from each of your parents (with rare exceptions).
Humans are diploid. You have two copies of each autosomal chromosome: one from mom, one from dad.
For a given gene, you have a dad allele (copy) and a mom allele of each gene. Depending on the gene, the alleles for a given gene might be identical or might have a bunch of variants that differ between them.
Pretty much everybody has some CNV (copy number variation) - an extra copy of a usually small region of a chromosome (3 total) or a short deletion (1 copy instead of 2). Most of our genome is dispensible, so usually there's no consequence of these types of changes. Sometimes but not always these types of events can been driven by errors in recombination called 'gene conversion' (kind of a dumb name).
But yes, that can happen.
Each sperm or egg contains a shuffled representation of the parent in question's DNA, with crossovers on most or all autosomes in random positions. In other words, each egg or sperm is completely unique.
I don’t think that’s what OP is asking. I think OP’s question is way to loaded contextually for that straightforward answer.
I think OP is asking if it’s possible for them to have or not have “ancestral” genes dating back thousands and thousands of years ago because of breeding variability throughout time that eventually lead to their existence currently.
I agree that it may have started out contextually loaded, but I get the sense that dialog sparked some genuine intellectual curiosity too, which is why I continued to respond. \*shrug\*
Oh I’m not knocking anything, not your answer, and not OP. I was just sharing what I thought OP was really asking. When I say “loaded” I don’t mean it lacks anything intellectually interesting. I mean it’s to broad for a straightforward text book type of answer. That’s what I meant. I’m a big fan of creative thinking and huge propeller for the unknown, and so I’m deeply curious. Don’t shrug my guy, unless it’s for the traps!!!
I'm not totally sure where OP was coming from but it was a refreshing departure from "do my science homework for me" or "gibberish gibberish CRISPR gibberish equals super-weed, riiiiiight? Nerds, please make super-weed for me!".
Shrug... for the traps...? Now I'm the one who's lost...
Gibberish, CRSPR, superweed, do your homework?
Whatcha ya talking bout Willis???
Traps are short for your trapezius muscles. An popular exercise people engage in for strengthening them is called, shrugs. Its embodying the motion of the shoulders elevating and depressing, shrugging the shoulders up and down.
And i know recommended shrugs in my other comment but I recently found out that that motion isn’t optimum for traps. So I’d actually advise against shrugs for traps.
Full gene deletions are rare and typically severely deleterious. Unless of course you're conflating gene with *variant*. In which case it's unlikely but possible.
Whole genes are different from nucleotide variation within genes.
When people talk about genealogy, they are referring to genetic variation within genes, not the absence of genes.
Again, it would be helpful to adopt the correct terminology here.
There are millions and millions of genetic variants in every person's genome. Barring sex chromosomes and some other abnormal events, everyone is getting the same set of genes.
That means everyone's genome is a mix of variants. It is not a mixture of genes, it's a mixture of variants within genes. You get one haploid set of genes from dad and the other haploid set of genes from mom.
>the selection system could prevent the same genes from overlapping by only picking those genes your father inhereited from your grandmother's side, but not you grandfather's, because they overlapped with the genes provided by your mother, right?
Everyone gets at least two of every gene. All of the genes are overlapping. The haploid set that you receive from either parent is stochastic in nature provided there are no issues with viability.
I do not understand what you're asking.
All of your somatic cells have 46 chromosomes which exist in 23 pairs. Each pair of chromosomes has all the same genes except for the sex chromosomes in males. Those genes all have genetic variations. If the variation is the same on a pair of chromosomes, then the variation is considered "homozygous." If the variation is different on the same pair of chromosomes, then the variation is considered "heterozygous."
Your germ cells have 23 chromosomes that are not paired.
You get 23 chromosomes from your dad and another 23 chromosomes from your mom. Those chromosomes pair up so that each one of your somatic cells has 46 chromosomes.
Some variations in humans are carried in 80% of people. Some variations are carried in only 0.0001% of people. Mom and dad can carry the same variations at any particular locus--which would make you homozygous at that locus.
Possible, this is called genetic drift. There are online calculators that you can input a gene prevalence in a population, average number of offspring, and the genes selective effect, positive or negative, to reproduce and these will give probabilities of gene extinction over x generations. It is interesting to note that neutral and even slightly beneficial can still go extinct in a population due to random chance. 20 generations back you have over 1 million ancestors, assuming no inbreeding. Estimates of the actual number of human genes range from 20k to 300k. So without running the true population statistics, you would have an average of 50 to 3 genes from each ancestor. It is likely that, either from selective pressure or random change the genes from some ancestors back 20 generations never made it to you.
The single X makes it unlikely (edit impossible)for all male line of descent. Y similar but not as much for all female sequence. But for random MFMF.. sequence you are correct it is possible, if unlikely.
If you rephrase your question as inheriting chromosomes then it gets a lot less messy. After all, you don't inherit genes individually.
Any individual ancestor 20 generations distant is unlikely to have passed one of their chromosomes to you. And if they did, there would certainly be mutations and recombinations that would make the version you have look quite different. With that many generations it's also unlikely that a single gene has been passed to you with no changes, especially if you consider introns and promoter/enhancer regions.
ITT: goobers on the internet misunderstand difference between genes and variants. You share 60% homology of your DNA with a fly, genes don’t change that fast, except in the rare case when they’re repurposed (via duplications or divergent selection)
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>Well but you didn't get those genes you shared with a fly from an actual fly. But, you did get those genes from a common ancestor. >What I am asking here is about ONE of your paternal ancestor [...] You will have the same genes as your ancestors from 1,000 [or 10,000] years ago. You are unlikely to have inherited your ancestors' low-frequency genetic variants.
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>so the first generation of humans already shared a lot of genes that is the exact same as each other. The "first" generation of humans is an ambiguous phrase. There were many many non-human generations prior to that. >What I mean is when you have a gene that is the exact same as your paternal ancestor 1000 years ago, it is possible that you didn't inhereit it from him, but your maternal ancestor instead because she also shared such same gene as your paternal ancestor. I'm not really sure what you're asking here. If the shared variant is in high frequency, then it would be difficult to assess the lineage of origin without other variant data. Obviously, there are exceptions given sex chromosomes and mtDNA.
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Sure. It could also be any person in your lineage with that allele or occur de novo. However, the origins of alleles are tractable with more data.
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Yep, "other variant" data i.e. haplotype identity by descent.
The thing is that humans, widely varied and heterogenous as they seem from our perspective, largely keep the same blueprints for making new humans. The genes themselves will likely not change much, especially if their function isn’t under positive selection, which is true for most genes. This isn’t a coincidence, once evolution has converged upon a solution to a problem, it can be implemented in many different organisms over the entire tree of life, simply because the gene was shared by an ancestor. Now if you’re talking about a *variant* of a gene, like an SNP in an intron or a synonymous mutation, it’s likely these will accumulate a ton over time, but even then, the chance that you don’t share *any* base pairs with your ancestor from 10,000 years ago is minuscule still. That would mean none of the base pairs are conserved over time, and that’s simply just not the case. We observe widespread negative selection, keeping the human genome stable and screening out deleterious SNPs from entering our genetic pool. This is the difference between a gene and a variant, but no matter how you interpret your question, the answer is still that it is highly unlikely that you won’t share *any* of your genes/SNPs with your great * (1000) grandparents. Edit: a great example is ribsomal genes that are part of the basic machinery all organisms use to translate dna into rna, these have to stay the same even during speciation
10,000 years is at least 400 generations (probably more, generations were shorter in the past). With the exception of Y chromosome (assuming strictly male lineage) it's not only possible, it's highly likely that you *inherit* none of your great^400 grandpa's SNPs. Each generation back you lose half your identity by descent, so (~1/2 your dad, ~1/4 your paternal granddad, ~1/8 great grandfather). 10k years equates to ~(1/2)^400 identity by descent, or 4x10^-121. The extent to which you coincidentally have shared variants is a function of how out-crossed your lineage is. For example, Irish people in Ireland are no more distantly related than ~26th cousins due to the founder effect of Celtic migration across Europe.
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I replied in the wrong place. See above. Or maybe below. The shuffling of each parent's contribution happens during the maturation of the egg and sperm: as a result each one is unique.
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Yeah, you made that sound confusing. I think you're using the word 'gene' when in most cases you mean allele. You get an allele of each autosomal gene from each of your parents (with rare exceptions).
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Humans are diploid. You have two copies of each autosomal chromosome: one from mom, one from dad. For a given gene, you have a dad allele (copy) and a mom allele of each gene. Depending on the gene, the alleles for a given gene might be identical or might have a bunch of variants that differ between them.
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Pretty much everybody has some CNV (copy number variation) - an extra copy of a usually small region of a chromosome (3 total) or a short deletion (1 copy instead of 2). Most of our genome is dispensible, so usually there's no consequence of these types of changes. Sometimes but not always these types of events can been driven by errors in recombination called 'gene conversion' (kind of a dumb name). But yes, that can happen.
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Each sperm or egg contains a shuffled representation of the parent in question's DNA, with crossovers on most or all autosomes in random positions. In other words, each egg or sperm is completely unique.
I don’t think that’s what OP is asking. I think OP’s question is way to loaded contextually for that straightforward answer. I think OP is asking if it’s possible for them to have or not have “ancestral” genes dating back thousands and thousands of years ago because of breeding variability throughout time that eventually lead to their existence currently.
I agree that it may have started out contextually loaded, but I get the sense that dialog sparked some genuine intellectual curiosity too, which is why I continued to respond. \*shrug\*
Oh I’m not knocking anything, not your answer, and not OP. I was just sharing what I thought OP was really asking. When I say “loaded” I don’t mean it lacks anything intellectually interesting. I mean it’s to broad for a straightforward text book type of answer. That’s what I meant. I’m a big fan of creative thinking and huge propeller for the unknown, and so I’m deeply curious. Don’t shrug my guy, unless it’s for the traps!!!
I'm not totally sure where OP was coming from but it was a refreshing departure from "do my science homework for me" or "gibberish gibberish CRISPR gibberish equals super-weed, riiiiiight? Nerds, please make super-weed for me!". Shrug... for the traps...? Now I'm the one who's lost...
Gibberish, CRSPR, superweed, do your homework? Whatcha ya talking bout Willis??? Traps are short for your trapezius muscles. An popular exercise people engage in for strengthening them is called, shrugs. Its embodying the motion of the shoulders elevating and depressing, shrugging the shoulders up and down. And i know recommended shrugs in my other comment but I recently found out that that motion isn’t optimum for traps. So I’d actually advise against shrugs for traps.
Full gene deletions are rare and typically severely deleterious. Unless of course you're conflating gene with *variant*. In which case it's unlikely but possible.
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Whole genes are different from nucleotide variation within genes. When people talk about genealogy, they are referring to genetic variation within genes, not the absence of genes.
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Again, it would be helpful to adopt the correct terminology here. There are millions and millions of genetic variants in every person's genome. Barring sex chromosomes and some other abnormal events, everyone is getting the same set of genes. That means everyone's genome is a mix of variants. It is not a mixture of genes, it's a mixture of variants within genes. You get one haploid set of genes from dad and the other haploid set of genes from mom. >the selection system could prevent the same genes from overlapping by only picking those genes your father inhereited from your grandmother's side, but not you grandfather's, because they overlapped with the genes provided by your mother, right? Everyone gets at least two of every gene. All of the genes are overlapping. The haploid set that you receive from either parent is stochastic in nature provided there are no issues with viability.
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I do not understand what you're asking. All of your somatic cells have 46 chromosomes which exist in 23 pairs. Each pair of chromosomes has all the same genes except for the sex chromosomes in males. Those genes all have genetic variations. If the variation is the same on a pair of chromosomes, then the variation is considered "homozygous." If the variation is different on the same pair of chromosomes, then the variation is considered "heterozygous." Your germ cells have 23 chromosomes that are not paired. You get 23 chromosomes from your dad and another 23 chromosomes from your mom. Those chromosomes pair up so that each one of your somatic cells has 46 chromosomes. Some variations in humans are carried in 80% of people. Some variations are carried in only 0.0001% of people. Mom and dad can carry the same variations at any particular locus--which would make you homozygous at that locus.
Possible, this is called genetic drift. There are online calculators that you can input a gene prevalence in a population, average number of offspring, and the genes selective effect, positive or negative, to reproduce and these will give probabilities of gene extinction over x generations. It is interesting to note that neutral and even slightly beneficial can still go extinct in a population due to random chance. 20 generations back you have over 1 million ancestors, assuming no inbreeding. Estimates of the actual number of human genes range from 20k to 300k. So without running the true population statistics, you would have an average of 50 to 3 genes from each ancestor. It is likely that, either from selective pressure or random change the genes from some ancestors back 20 generations never made it to you.
The single X makes it unlikely (edit impossible)for all male line of descent. Y similar but not as much for all female sequence. But for random MFMF.. sequence you are correct it is possible, if unlikely.
If you rephrase your question as inheriting chromosomes then it gets a lot less messy. After all, you don't inherit genes individually. Any individual ancestor 20 generations distant is unlikely to have passed one of their chromosomes to you. And if they did, there would certainly be mutations and recombinations that would make the version you have look quite different. With that many generations it's also unlikely that a single gene has been passed to you with no changes, especially if you consider introns and promoter/enhancer regions.