""In humans, it is estimated that there are about 30 mutations per individual per generation, thus three in the functional part of the DNA. This implies that on the average there are about
3/2000 beneficial mutations per individual per generation and about 1.5 harmful mutations.""
check and mate
I see you cherry picking a source since the rest for your source says the complete opposite.
Like this part:
"To be precise about the human situation, there are about 3.5 * 10 9 base pairs in the human genome, and each person has two copies of these, one from the father and one from the mother. The rate of mutation in humans is believed to be about 1 * 10 -8 per base pair per generation, or, 35 mutations per generation per individual. We can assume that 9/10 of these occur in the non-functional part of the DNA, and that of the remainder, possibly half are neutral, leading to about 1.75 harmful or fatal mutations per generation. Now, the typical individual will have mutations from both parents, and therefore will have about 3.5 harmful mutations per generation. Let's divide a generation into n small time intervals; then the chance of a harmful mutation during 1/n of a generation is 3.5/n, and the chance to avoid a harmful mutation during this small time interval is 1 - 3.5/n. Thus the chance to avoid any harmful mutations during the entire generation is (1 - 3.5/n)n, which is about (1/2.718)3.5, or, 0.0302084. This means one child free of defects per 33.1 children. In order to have two children free of defects on the average, to avoid error catastrophe, the typical female would need 66 conceptions! ReMine obtains a figure of 16.3 conceptions assuming only 3 percent of the DNA is functional. Both are unrealistically large. The consequence is that humans are experiencing error catastrophe, that is, instead of evolving, we are degenerating. This implies that at one time humans were much more advanced than we now are. This is consistent with a creationist view that the human race was created with so much vitality that it could endure the degeration resulting from harmful mutations.
It is important in this respect to understand what a harmful mutation is. It must be a mutation that hinders the organism in a way that the organism is not able to compensate for. Since populations are generally stable over long time periods, this means that an organism with a harmful mutation will typically have less than one surviving offspring.
Equilibrium is the state at which the frequencies of occurrences of various mutations are fixed over time. After sufficient time, any population with constant rates of mutation should reach equilibrium. When the population reaches equilibrium, harmful mutations will be entering and leaving the population at the same rate. This means that a mutation that is only slightly harmful will spread to much of the population, but a mutation that is very harmful will spread to a small percent of the population. But both mutations will cause a number of deaths per generation equal to their frequency of occurrence in the population. So the chance that a fertilized egg will survive is less than or equal to the chance that it has no new harmful mutations, when the population is at equilibrium. Thus if there is a small chance that an offspring will be free of new defects, then there is a small chance that it will survive, when the population is at equilibrium. So at equilibrium we should expect that only about one in 33 fertilized human eggs will survive, based on the above calculations.
It is also important to understand that only essential genes will persist in a population as functioning genes for long periods of time. Inessential genes will suffer mutations that destroy their function, and since the organism is able to compensate, such mutations will accumulate over time until the gene is non functional in the whole population. This means that evolution eventually eliminates all redundancy, and only the genes that an organism really needs to survive will be maintained. So all species will eventually be living on the edge of extinction, in a sense.
One way to understand how the human race can endure a high rate of mutation is to realize that many mutations are recessive. They are only expressed (fully) when both copies of the gene have the mutation. Mutations to enzymes tend to be recessive, because an organism with one gene generating functioning enzymes can still survive, though possibly with some degradation. Mutations to structures of an organism tend to be dominant. Now, recessive mutations tend to accumulate until there are enough of them to be expressed. Assuming 10-8 point mutations per base pair per generation, a recessive mutation would accumulate until it reaches equilibrium, when the numbers of mutations entering and leaving the population are equal. Assuming the mutation were fatal, this would happen when about 1/10,000 of the individuals had a mutation at this base pair, since the probability of expression would be the square of 1/10,000, or 1/100,000,000, the same as the probability of the mutation occurring. It would take on the order of 10,000 generations to reach equilibrium (actually, somewhat longer). Now, there may be about 3*108 functional base pairs in the human genome. It would be reasonable to assume that half of these were for enzymes, which might mean about 108 recessive fatal mutations. When each reached equilibrium, a typical individual would have about 10,000 recessive mutations. Each child would then on the average have one of them expressed. This would be essentially the same as if there were one fatal mutation per generation at the start; the cost to the population is the same, but recessive mutations take longer to reach the full cost."