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Old 08-30-2017, 05:00 AM
 
Location: Austin
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You are 1/4 each. What DNA comes from whom is irrelevant
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Old 08-30-2017, 12:12 PM
 
Location: The High Desert
16,087 posts, read 10,753,057 times
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Quote:
Originally Posted by Bruins3445 View Post
Say for example my father is Italian and French.
My mother is Japanese and Lebanese.

Does that make each child a quarter of each? Or do we only inherit one from each parent?

...

Going back to my original example, if I thought I was 1/4 lebanese, 1/4 French, 1/4 Japanese, and 1/4 Italian but in reality I may only be half Japanese half French, OR half Japanese half Italian. OR half Lebanese half French OR half Lebanese half Italian...?
Ethnicity identification is largely cultural but you will inherit a chunk from each grandparent. When we were younger, my brother looked nothing like me. It seemed we were from different parents but now in our 70s we are unmistakably brothers...even to total strangers. It seems a lot of the appearance differences among younger siblings will diminish with age.
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Old 08-30-2017, 01:05 PM
 
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Just call yourself a Heinz 57.

Genetically and racially, Lebanese, Italian, and French are all basically the same anyway.
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Old 08-30-2017, 02:51 PM
 
10,075 posts, read 7,544,097 times
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Quote:
Originally Posted by Bruins3445 View Post
Say for example my father is Italian and French.
My mother is Japanese and Lebanese.
if you were born and raised in spain, I'd call you Spanish and ignore what your parents are...

why? because your list of "nationalities" aren't ethnicities
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Old 08-30-2017, 08:40 PM
 
16,825 posts, read 17,736,880 times
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Quote:
Originally Posted by brownbagg View Post
in theory yes but in reality no, they no way to tell how much you can receive, there been some study where grandparent had some native american and one grand kid had some and the other had zero. Even the parent would not be a perfect 50-50
That is not true.

Unless you have a genetic abnormality, you inherent one copy of each chromosome from each parent so it is not possible that each parent does not contribute 50% of the genetic material.
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Old 08-30-2017, 08:47 PM
 
16,825 posts, read 17,736,880 times
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Quote:
Originally Posted by Bruins3445 View Post
Say for example my father is Italian and French.
My mother is Japanese and Lebanese.

Does that make each child a quarter of each? Or do we only inherit one from each parent?

I'm wondering if this could explain how in larger families, the kids can vary so greatly and not resemble each other, sometimes not resembling parents.

Does this boil down to inheriting specific features that could affect that?


I'm wondering if anyone has done some of those genetic tests and found that they aren't the ethnicity they thought they were?

Going back to my original example, if I thought I was 1/4 lebanese, 1/4 French, 1/4 Japanese, and 1/4 Italian but in reality I may only be half Japanese half French, OR half Japanese half Italian. OR half Lebanese half French OR half Lebanese half Italian...?


Does that make sense? If I remember back to school days where we learned about genetics I thought we could only inherit one from each parent. And I'm wondering if anyone can clarify does that boil down to inheriting the Genes of one ethnicity from each parent? Or are we automatically a mixture of whatever ethnicities our parents are?
Parents have two copies of each chromosome. On each chromosome are genes which code for and contribute to different traits. Parents will contribute one chromosome each, sometimes when the chromosomes are near each other during cell division some of the genes switch from one chromosome to another. So if one of dads chromosomes was traits a,b,c and another chromosome was traits 1,2,3 when he gives his chromosome to his child, he may give a,2,3 to one kid, and a,b,3 to another and any combination thereof. Likewise for mom except it is about 30,000 genes instead of 3.

It gets even more compicared because it isn't like a means a big nose and 1 means a small one. Most traits are due to the interaction of many genes.

Finally, ethnicities do not translate to different genetics. Most people, regardless of where they come from have the same types of genes at each loci.
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Old 08-30-2017, 08:54 PM
 
16,825 posts, read 17,736,880 times
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Quote:
Originally Posted by PA2UK View Post
Everyone inherits 50% of their DNA from each of their parents (well, give or take a couple percentages - I actually share 52.7% with my mom, so only 47.3% from my dad). But we don't inherit exactly 25% from each grandparent. For example, I share only 20.3% with my paternal grandfather so I got about 27% from my paternal grandmother. However, it's extremely unlikely that you would inherit 0% from one grandparent and the full 50% from another. So while you might be 20% Lebanese, 30% French, 22% Japanese, and 28% Italian, you would not be only half of two of those.
This is also not true.

u less you have had your entire genome sequenced, as well as that of your parents and grandparents this would be impossible to know anyway.

I think you might be confusing the percentages from those DNA heritage websites. The do not sequence all of your DNA at least not typically. Instead the look at a small percentage of your DNA that tends to be similar in certain groups and en extrapolate. But if someone who say has one European parent and one Asian comes back with 54% Asian that does not mean they got more than 50% of their DNA from the Asian parent it means their parent of European ancestry has a small amount of genes typically associated with Asian ancestry.
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Old 08-30-2017, 10:47 PM
 
Location: Georgia, USA
37,106 posts, read 41,277,178 times
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Quote:
Originally Posted by lkb0714 View Post
Parents have two copies of each chromosome. On each chromosome are genes which code for and contribute to different traits. Parents will contribute one chromosome each, sometimes when the chromosomes are near each other during cell division some of the genes switch from one chromosome to another. So if one of dads chromosomes was traits a,b,c and another chromosome was traits 1,2,3 when he gives his chromosome to his child, he may give a,2,3 to one kid, and a,b,3 to another and any combination thereof. Likewise for mom except it is about 30,000 genes instead of 3.

It gets even more compicared because it isn't like a means a big nose and 1 means a small one. Most traits are due to the interaction of many genes.

Finally, ethnicities do not translate to different genetics. Most people, regardless of where they come from have the same types of genes at each loci.
Genetic autosomal DNA testing uses single nucleotide polymorphisms - SNPs.

https://ghr.nlm.nih.gov/primer/genomicresearch/snp

"Single nucleotide polymorphisms, frequently called SNPs (pronounced “snips”), are the most common type of genetic variation among people. Each SNP represents a difference in a single DNA building block, called a nucleotide. For example, a SNP may replace the nucleotide cytosine (C) with the nucleotide thymine (T) in a certain stretch of DNA."

"SNPs occur normally throughout a person’s DNA. They occur once in every 300 nucleotides on average, which means there are roughly 10 million SNPs in the human genome. Most commonly, these variations are found in the DNA between genes. They can act as biological markers, helping scientists locate genes that are associated with disease. When SNPs occur within a gene or in a regulatory region near a gene, they may play a more direct role in disease by affecting the gene’s function.

Most SNPs have no effect on health or development ... "

https://www.23andme.com/gen101/snps/

"DNA is passed from parent to child, so you inherit your SNPs versions from your parents. You will be a match with your siblings, grandparents, aunts, uncles, and cousins at many of these SNPs. But you will have far fewer matches with people to whom you are only distantly related. The number of SNPs where you match another person can therefore be used to tell how closely related you are."

Y-DNA testing as done by Family Tree DNA looks at short tandem repeats: STRs.

https://www.familytreedna.com/learn/...ces-snps-strs/

"A SNP is a single nucleotide polymorphisms. That means that it is a single small change in your DNA code. These changes are rare. Once they happen, they seldom change back (back mutate).

An STR is a short tandem repeat. This is a place in your DNA code where a letter sequence is repeated. For example, AGTAAGTAAGTA is three repeats of the sequence AGTA. STRs have a fast mutation rate. When they change, it is an increase or decrease in the number of repeats. STR values changing back (back mutate) more common."


Quote:
Originally Posted by lkb0714 View Post
This is also not true.

u less you have had your entire genome sequenced, as well as that of your parents and grandparents this would be impossible to know anyway.

I think you might be confusing the percentages from those DNA heritage websites. The do not sequence all of your DNA at least not typically. Instead the look at a small percentage of your DNA that tends to be similar in certain groups and en extrapolate. But if someone who say has one European parent and one Asian comes back with 54% Asian that does not mean they got more than 50% of their DNA from the Asian parent it means their parent of European ancestry has a small amount of genes typically associated with Asian ancestry.
Yep, it's true.

Since the report is given as a percentage it is not necessary to sequence the entire genome.

You get 50% from each parent. The genealogy test will tell you how much of the tested DNA you share with someone. That will be about 50%, close enough to show a parent child relationship.

The percentages do get a bit skewed when you get back to the grandparents, though, due to recombination. Eventually, you get to a point where recombination has completely eliminated any DNA from some individuals. You do not have bits of DNA from every single ancestor you ever had.

Recombination gets ... complicated. You may get significantly more or less than 25% from a grandparent. Recombination rates differ for different chromosomes and differ for males and females.

https://gcbias.org/2013/10/20/how-mu...r-grandparent/

"I was a little surprised by how long tailed this was in males. Roughly 5/1000 fathers transmit less than 20% of one paternal grandparent’s autosome to the next generation!"

The ethnicity percentages are based on comparing the DNA tested with a reference database of known ethnicity (based on reports from people about where their most recent ancestors came from). Different companies use different references and come up with different ethnicity percentages, which are always estimates. It is pretty good at identifying the continent that your ancestors came from but not so good at narrowing it down much further, unless your heritage includes a significant degree of endogamy, such as being Ashkenazi Jewish.

Keep in mind that it is DNA being tested, not genes, per se. See SNPs and STRs above.
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Old 08-31-2017, 10:46 AM
 
16,825 posts, read 17,736,880 times
Reputation: 20852
Quote:
Originally Posted by suzy_q2010 View Post
Genetic autosomal DNA testing uses single nucleotide polymorphisms - SNPs.

https://ghr.nlm.nih.gov/primer/genomicresearch/snp

"Single nucleotide polymorphisms, frequently called SNPs (pronounced “snips”), are the most common type of genetic variation among people. Each SNP represents a difference in a single DNA building block, called a nucleotide. For example, a SNP may replace the nucleotide cytosine (C) with the nucleotide thymine (T) in a certain stretch of DNA."

"SNPs occur normally throughout a person’s DNA. They occur once in every 300 nucleotides on average, which means there are roughly 10 million SNPs in the human genome. Most commonly, these variations are found in the DNA between genes. They can act as biological markers, helping scientists locate genes that are associated with disease. When SNPs occur within a gene or in a regulatory region near a gene, they may play a more direct role in disease by affecting the gene’s function.

Most SNPs have no effect on health or development ... "

https://www.23andme.com/gen101/snps/

"DNA is passed from parent to child, so you inherit your SNPs versions from your parents. You will be a match with your siblings, grandparents, aunts, uncles, and cousins at many of these SNPs. But you will have far fewer matches with people to whom you are only distantly related. The number of SNPs where you match another person can therefore be used to tell how closely related you are."

Y-DNA testing as done by Family Tree DNA looks at short tandem repeats: STRs.

https://www.familytreedna.com/learn/...ces-snps-strs/

"A SNP is a single nucleotide polymorphisms. That means that it is a single small change in your DNA code. These changes are rare. Once they happen, they seldom change back (back mutate).

An STR is a short tandem repeat. This is a place in your DNA code where a letter sequence is repeated. For example, AGTAAGTAAGTA is three repeats of the sequence AGTA. STRs have a fast mutation rate. When they change, it is an increase or decrease in the number of repeats. STR values changing back (back mutate) more common."




Yep, it's true.

Since the report is given as a percentage it is not necessary to sequence the entire genome.

You get 50% from each parent. The genealogy test will tell you how much of the tested DNA you share with someone. That will be about 50%, close enough to show a parent child relationship.

The percentages do get a bit skewed when you get back to the grandparents, though, due to recombination. Eventually, you get to a point where recombination has completely eliminated any DNA from some individuals. You do not have bits of DNA from every single ancestor you ever had.

Recombination gets ... complicated. You may get significantly more or less than 25% from a grandparent. Recombination rates differ for different chromosomes and differ for males and females.

https://gcbias.org/2013/10/20/how-mu...r-grandparent/

"I was a little surprised by how long tailed this was in males. Roughly 5/1000 fathers transmit less than 20% of one paternal grandparent’s autosome to the next generation!"

The ethnicity percentages are based on comparing the DNA tested with a reference database of known ethnicity (based on reports from people about where their most recent ancestors came from). Different companies use different references and come up with different ethnicity percentages, which are always estimates. It is pretty good at identifying the continent that your ancestors came from but not so good at narrowing it down much further, unless your heritage includes a significant degree of endogamy, such as being Ashkenazi Jewish.

Keep in mind that it is DNA being tested, not genes, per se. See SNPs and STRs above.
Thanks for the blogsplaining but as I am more than passing familiar with genetics due to my science degrees I am still confident that I am not wrong. What the person I quoted stated that I said was untrue that they got more than 50% of their DNA from their father. That is not true. Your moving the goal posts to grandparents does not disprove my point about his parents.
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Old 08-31-2017, 11:55 AM
 
Location: North Carolina
10,214 posts, read 17,881,804 times
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Quote:
Originally Posted by lkb0714 View Post
What the person I quoted stated that I said was untrue that they got more than 50% of their DNA from their father.
Lol, that's not even what I said. Try actually reading what you quote.
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