It is really irrelevant whether Darwin knew about Mendel's work or not. He knew enough about genetics to know that certain observable phenotypes may be passed from parent to offspring.
What mendellian genetics shows is that it is very difficult, if not impossible to pass on a new trait throughout an entire population.
It shows nothing of the sort. A favorable mutation is one that, by definition, confers a survival advantage to the organism. An organism with an advantage has a better chance of reproducing, thus of spreading the mutation. An unfavorable mutation tends to be bred out of a population, and a neutral mutation remains in the population at pretty much a stable frequency. The spread of mutations throughout a population is not random, nor does it take a long time. This is all basic biology, which is usually taught in freshman level biology courses.
Now evolutionists thing that there has been enough time for all these new genes to spread throughout all these different species, but that is not the case. The two-three billion years since life began on earth are insufficient time for the numerous mutations that were necessary to spread throughout all living things when the delays caused by Mendellian genetics are taken into account.
Actually, a couple of billion years is an inconceivable amount of time. Consider how quickly the flu virus mutates itself, or how quickly bacteria develop resistances to new antibiotics, or insects to new pesticides. These events take only a handful of years.
Funny you should mention the above. I really think of those as proof against evolution. Here's why: although these creatures are allegedly mutating a lot, they are still viruses, still bacteria, still the same insects. Now one would think that if evolution is true, we would see more change in these creatures than just a new resistance to a drug. That can happen with a small single mutation in a single gene or by other means. As I have pointed out on these threads, you need a lot more than that to get from bacteria to man. You really need the transformation of organisms and this is not happening in the above cases. This transformation has never been observed in any of these organisms even though they seem to quite easily adapt themselves to new circumstances. Since adaptation to the environment is supposedly the engine of evolution, one would think that for example some of these viruses would have become bacteria by now.
BTW the above also deals with the problems of abiogenesis. Some evolutionists have said that because viruses are made of RNA only that this is the way life started. However, viruses do not reproduce. They are parasites and can only replicate through infecting a host cell. The fact that in spite of the tremendous amount of research on viruses by the medical community, no evolution of these viruses into self-replicating organisms has been seen is strong proof against both the theory of evolution and theories of abiogenesis.
It shows nothing of the sort. A favorable mutation is one that, by definition, confers a survival advantage to the organism. An organism with an advantage has a better chance of reproducing, thus of spreading the mutation. An unfavorable mutation tends to be bred out of a population, and a neutral mutation remains in the population at pretty much a stable frequency. The spread of mutations throughout a population is not random, nor does it take a long time. This is all basic biology, which is usually taught in freshman level biology courses."
Let's take this one step at a time. Darwin's view was that if an individual had a mutation it had a 100% chance of being passed on to the next generation because he thought the traits of the parents "melded" in the progeny. Mendellian genetics showed this is not the case. First of all, if a new gene is recessive, it will never spread through the species. Now, even on the 50/50 chance that it would be a dominant gene, the chances of its spreading are pretty thin indeed. Remember, this is a new gene, noone else in the species has it. When the individual mates with another the chance will be 50/50 the progenitor will get the gene. If the progenitor does not marry a sister which got the gene (on the 50/50 chance also), the chances are 50/50 again. If it does not marry a cousin (who through a 1 in 4 chance got the gene), or if he was an only child the chances will be 50/50 again. We are already down to a 1/8th chance in just 3 generations of this very good gene from spreading. Even in a small population, the chances of this gene spreading are slim. That is why Kirmura had to invent (out of whole cloth) the genetic drift concept - to try to solve the problem of genetics. It was also one of the reasons Gould said that evolution took place in small populations - because it was so hard to spread even a very good new gene through a large population. So yes, Mendellian genetics does make evolution very hard - and Mendellian genetics is taught in high school biology classes (but its consequences to the theory of evolution are not which is why we need real science taught in schools not evolution).