Have scientists worked out that the average genetic mutation is during fertilisation (combining of the 2 chromosomes from the 2 parents) for humans is?
i.e. How different from the combination of our parent’s genetic information are we?
Note, I am just a student whose had a few classes in genetics/molecular biology - if this is very wrong, or way to generalized, its because I’m going by memory!
IIRC correctly there is an approximate rate of “wrong base insertion” during DNA replication. This wrong base might be one that causes no significant change, such as a change that leads to use of the same amino acid when the gene gets used to make a protein. Or, the change can be a bit bigger, but not too bad - like a change from lysine to arginine, which physiologically have the a similar charge and basicity, and so the overal protein doesn’t change much, but might have a slight effect (prehaps better or worse action, but not too significantly to the organisms health). Or the change can be more drastic - something that will disrupt the protein folding, or truncate the protein, etc, so that the protein doesn’t work at all, or barely functions.
Of course, a LOT of DNA is considered to be “junk DNA”, in which there is nothing coded for. These are the introns, that are removed before any protein gets made from the DNA (in eukaryotes, at least - like us). So if a mutation occurs in junk DNA, it will most likely have actually no effect on the organism, and since most DNA is junk, well, then, actual passed down mutations are pretty limited from one generation to another.
I seem to remember the “wrong base pair insertion” rate to be something like 10x10^(-8), but I don’t have my textbook handy. There are a lot of factors that can affect this rate, though, such as chemical mutagens (drugs, etc) or overexposure to UV-light.
One more thing about your original question, though: there is no frequency of mutation occuring during fertilization. Any mutation that might occur is done during meiosis, that is, when the precursor cells to the egg and sperm divide themselves to make sperm and eggs. Or possibly during a mitosis stage, in which these precursor cells divide simply to reproduce themselves. It would take direct exposure to a source of mutagenicity (?) to cause a spontaneous mutation, which is something that doesn’t usually happen, so stats for it are most likely non-existant (although theres plenty of stuff on E. Coli if you wish to learn more).
As I understand it different genes can mutate in different ways at different paces. One of the places I’ve been looking at lately are certain markers in the Y chromosone which mutate slowly and are used for genealogical research. The same ones in the whole Jefferson/Hemmings research.
Here a Professor from the University of Arizona reviews (the?) two ways that these markers can mutate. And while a rate of 0.002 is the standard rate used the people over at this mailing list are finding that some markers mutate faster and others mutate slower. Some markers for instance might remain inchanged for 1000s of years whereas other markers might change every few generations. However these markers are in the “junk” area since they don’t really do anything.
Anyway in order to find the average mutation rate per generation for a person’s entire set of DNA would require reading the entire set for parents and child. And repeating it many times with other families. And then comparing the enormous amount of data. Since this still takes a very long time we only have guesstimates arrived at by looking at small pieces of DNA in limited studies. I think we stand a good chance of having a good answer in 10 years.