Genealogy Chat

Richard, I saw that discussion a few weeks ago and remember thinking how mistaken that guy was. Anyway, Google 'Mitochondrial Eve'. That's just one example of DNA we get from the female side, regardless of our sex. Rose

This from my daughter who is about to start studying forensic science majoring in biology. Also explains why my parents ( Both black haired ) had 3 children with black hair and one with pure almost snow white hair. My Grandfather was snow white! ( Unless my mother slept with the postman!!!LOL!) jackie

Hello, I am the daughter of Jackie and she asked me about this question so I thought that I'd provide some input that might help you out Regardless of what sex you are, you will contain genetic material from all of your grandparents... Let me explain... The concept that we get 50% of our genetic material from each parent is correct, however it is not necessarilly true that all genetic material from one specific parent will show as well as the genetic material from the other parent. It's a difficult idea to comprehend, but in simpler terms: Each egg and each sperm contains half the number of chromosomes (which contain the DNA/genetic material) than the parent. Each egg and sperm will recieve its genetic material from a random formation during cell separation - This is where differences come from - we have so many chromosomes that it's unlikely that two siblings will have the exact same chromosome inheritance. Further more, Chromosomes contain dominant and recessive genes. For example (a very simple example - hair is more complicated than this but i'm simplifying it down) - a gene for hair is inherited by both parents, that is, they provide a possibility for certain genetic material to be displayed. If your mother has brown hair and your father has blonde hair, you will inherit both genes, but will only display the dominant gene, in most cases, the brown hair. It gets even more difficult if a brown haired person that CARRIES the gene for blonde hair has a child with someone with the same genetic characteristic - this produces fully recessive characteristics as there is a 1/4 chance that the recessive (blonde) genes will combine in the zygote and produce a child that displays a different characteristic to both parents. To say that you dont inherit any characteristics from your grandparents is highly silly, as genetics are passed down generation to generation, however, to say that we inherit exactly 25% of one of our grandparent's genetics is slightly untrue - A lot of our genetic material is unique to us (as in, we haven't inherited it from either parent - this is what distinguishes us from another person during forensic analysis - even if we were in a murder investigation and the two suspects were siblings, Forensic analysts would focus on the 'non coding DNA' which is different regardless of relations to other people, thus, would produce a 99.9% positive chance even if the siblings were very similar) Whilst we will inherit 25% of the genetic material from each grandparent, the characteristics displayed in an individual aren't likely to be that simple - whilst we could inherit 25% of our material from one grandparent, it is possible that we only display 1% of that data, as the other 24% is dominated by a gene from a separate grandparent. I hope this helps you understand a little better. Everyone you find in your family tree you will have a slight genetic relation to - the closer they are to your direct family the more similarities there will be in the coding DNA - far distant relatives will have a much smaller coding-DNA similarity to you, but to say that you contain no genetic information from a specific side of your family or grandparent is completely silly... that is, unless you were a pure clone of one specific parent, which has never been attempted. ;) -Sarah

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About a week ago here, on a discussion about whether one should 'waste time' on following sideways branches on trees, a member here said not only would he not do so, he'd also not bother doing his maternal grandmothers ancestors, because as a male child of his mothers he would share zero genetic material with her. I found this disturbing. First that's 25% of my tree (probably the most researched 25% as it happens) pretty much written off. Second my grandma was rather dear to me bless her, and to think I share no genetic material from her was a shock. I have not been able to find any info online that can either confirm or deny this. I'm certainly no expert on the subject..but did do genetics breifly at school , and as I remembered it you got half your genes from mum, half from dad...so therefore 25% from each grandparent? (or so I'd always assumed!) Perhaps someone could explain it for me, been bothering me for a week now this!.