This is nonsense on two counts. First, we can trace phylotype to genotype with increasing accuracy with each passing year so that we know that species characteristics are determined by the genetics. Second, we can look at the variations and divergences in succeeding generations of a species and trace those variations and divergences to genetic mutations and not just different expressions of the same DNA.
That natural selection plays only a minor role is the really surprising part of your claim. I did not know that there was anyone that did not believe that the ability of a species to survive was related to its fitness for the environment in which it lives.
Dolphins do well in the tropics, but not the arctic where walruses and orca seem to do just fine. Polar bears don't wander through Rock Creek Park in DC for the simple reason that they cannot survive.
Mountain goats do wonderfully in places where I would not survive a day. If I try to swim with crocodiles, I will be dead, and I only survive because my brain is smart enough not to try to do it.
The whole notion that natural selection does not matter is just plain silly.
You've misunderstood me. Natural selection was a creationist idea (cf. Edward Blythe), and I regard its operation as tautological (that is, true by definition).
What is relevant though, is what power does natural selection have to drive change, even if mutational 'raw material' is available to fuel that change? I long believed its power was substantial, but my belief in the power of natural selection to drive actual genomic change has evaporated to virtually nothing in recent years.
Natural selection can prevent the most obviously lethal and defective mutations from spreading through a genome, but it turns out it can do practically nothing to prevent the accumulation of large numbers of near-neutral harmful mutations. And even when a beneficial mutation does occur the odds of it being fixed are quite low. The standard rule of thumb in population genetics is Y=2X, where Y is the % increase in offspring and X is the chance for the mutation involved to spread through the species rather than dying out. (This is for sexually reproducing populations.)
For example, let's say a mutation gave total immunity to a disease that kills 1% of a given population. All other things being equal, it would have a 2% chance of becoming 'standard' throughout the population eventually. The other 98% of the time it would die out by dumb luck even though it is beneficial. So the same mutation has to occur dozens of times to have a reasonable chance at being adopted, and this for a fairly remarkable beneficial mutation, as mutations go.
In the meantime, though, the 'mutational garbage' of near-neutral mutations just keeps piling up. With around 3 billion base pairs, a point mutation rate of c. 1 in 100 million (thus c. 30 point mutations/offspring), and hundreds more mutations from various transpositional changes, the human genome is in a state of inevitable deterioration. Natural selection is only able to fight a rear-guard action, and a feeble one at that.