Two things. First of all, Fred mentions the miscarriage rate. I have seen several sources that reported that the spontaneous miscarriage rate is over 50%. Most of these are not even recognized as anything other than a late period. Here is a link:
Recurrent Spontaneous Abortions
From the link:
quote:
15 - 20 % of all pregnancies will endup as early prenancy losses. These losses however, are those recognised pregnancies which are confirmed usually 4 to 5 weeks after conception. There is now evidence that the pregnancy loss rate before this period i.e., during the 2 to 3 weeks following conception, may be as high as 50 %.
Now if I am reading that right, it says the total miscarriage rate is 15-20% that are recognized, and about 50% that aren't.
Second, the overall mutation rate for humans is around 100. Here are some links that discuss this:
quote:
In humans and other mammals, uncorrected errors (= mutations) occur at the rate of about 1 in every 50 million (5 x 10^7) nucleotides added to the chain. (Not bad - I wish that I could type so accurately.) But with 6 x 10^9 base pairs in a human cell, that mean that each new cell contains some 120 new mutations.
http://users.rcn.com/...tranet/BiologyPages/M/Mutations.html
quote:
Our data suggest an overall mutation rate of 2.14x10-8 per base per generation, or 128 mutations per human zygote.
Mutation rates in humans. II. Sporadic mutation-specific rates and rate of detrimental human mutations inferred from hemophilia B - PubMed
quote:
The average mutation rate was estimated to be approximately 2.5 x 10(-8) mutations per nucleotide site or 175 mutations per diploid genome per generation.
Estimate of the mutation rate per nucleotide in humans - PubMed
FK