A barrier to macroevolution & objections to it

The formation of novel organs for one thing...

Here's how some scientists think some eyes may have evolved: The simple light-sensitive spot on the skin of some ancestral creature gave it some tiny survival advantage, perhaps allowing it to evade a predator. Random changes then created a depression in the light-sensitive patch, a deepening pit that made "vision" a little sharper. At the same time, the pit's opening gradually narrowed, so light entered through a small aperture, like a pinhole camera.

Here's how some scientists think some eyes may have evolved

I've been asking for empirical proof that mutation is the mechanism accounting for all the variation of life. Being as this is the fundamental concept on which evolution stands or falls, that doesn't sound like an unreasonable request, does it?

Did you read and understand the entire piece? Or did you simply latch onto a couple of sentences that you thought would support your unfounded disbelief?

The conclusion regarding the evolution of the eye is based on a series of logical steps, small changes, that could have occurred over time.

In addition, there are currently in existence living organisms that exhibit each of these steps.

In addition, there are currently in existence living organisms that exhibit each of these steps.

I ask because all you've given was a argument of incredulity which not very convincing at all.

Do you have any reason but your own incredulity to doubt that mutations (an empirically observed fact) over time will add up and create novel lifeforms with (yes) new organs?

the ToE seems to a priori disregard the possibility that there may be obstacles to mutation as a mechanism for accounting for all of life's diversity. ToE makes the grand and sweeping assertion that mutation IS a sufficient mechanism to account for such change.

But it doesn't seem to even look for possible obstacles. It just assumes there are none.

If you think obstacles exist, produce the evidence.

Angelini and Kaufman writes:The Coleoptera are perhaps the most successful lineage of animals, with over 350,000 described species (29). They are characterized by the modification of the forewings into elytra, a protective covering over the abdomen. Therefore, in Coleoptera, such as the red flour beetle, Tribolium castaneum, flight is dependent dependent on the hindwings (T3), which are similar to the single pair of wings (T2) in Diptera. What is the role, if any, of Ubx in these modified forewings, the elytra? It is possible that Ubx acts to modify wing development to produce elytra from the T2 segment in Tribolium, just as it does in the T3 disc of Drosophila to produce halteres. Alternatively, Ubx may simply identify T3 structures and regulate a separate set of target genes to allow hindwing development in the beetle. Recently, these hypotheses were tested by Tomoyasu and coworkers, who used RNA interference to suppress Ubx function in Tribolium larvae (87). They found that with the reduction of Ubx activity the T2 and T3 dorsal imaginal discs develop as elytra. Similarly, mutations in the Tribolium Scr orthologue, which is expressed in theT1segment, produce ectopic elytra-like structures on T1, rather than wing-like structures (14, 15). The Antp orthologue in Tribolium appears to have no influence on the identity of elytra or hindwings, since its suppression causes no defects in these structures (87). Therefore, in the absence of input from Hox genes, such as Ubx, the dorsal imaginal discs develop as elytra. This contrasts the situation in Drosophila, where in the lack of Ubx the imaginal discs develop as two pairs of wings (57). Furthermore, Tomoyasu and coworkers have shown that in Tribolium, Ubx does not repress target genes as it does in the haltere disc of Drosophila. Instead, these genes are expressed in unique patterns in the elytra that are independent of Ubx regulation. It seems likely that the ancestral role of Ubx has been to identify T3. During evolution, as T2 and T3 structures were modified differently in separate lineages, different target genes came under Ubx regulation in order to produce distinct morphologies unique to T3. In this example, the unregulated (or at least Hox-free) pathway has diverged to produce the elytra developmental program. However, for the T2 discs to develop as elytra and to retain a functional pair of hindwings, Ubx would have to acquire regulatory control over wing development in order to preserve this developmental mechanism. This is very different from the evolutionary scenario imagined for the Diptera, in which the evolution of a novel structure (halteres) was accompanied by the appearance of novel regulatory relationships to produce that structure. Forewing modifications appear in other insect groups as well. The forewings of Orthoptera are modified into a leathery protective form called tegmina. Many species of Heteroptera feed on plants, from which they acquire toxic substances used to deter predators. The forewings or hemelytra are often thickened proximally and brightly colored to advertise the insects’ toxicity. It is interesting to speculate whether modifications in wing patterning seen in the evolution of coleopteran elytra might also have been paralleled in the evolution of these other modified forewings, and whether the development of the more typical hindwings is dependent on suppression of the modified developmental mechanisms by Ubx.

How do we know that they are related or transitional?