You seem to have forgotten the questions; please give them a shot:
What do you mean by animal 'type'?
I use type because I find it hard to understand what evolution means by species. But it would be like a species. The reason I say type is that as with say bats there are many species that still look like bats. So I say they are the same type of animal. Even evolution has several meanings for species so its a bit ambiguous.
What is the smallest difference in shape that would qualify for a 'different shape' as you would assess it? (a couple of examples would be useful).
I guess any shape that makes a different animal. So a dog like creature
to a aquatic like creature in Kutchicetus.
(Pakicetus)
Its not just the shapes but also the features. Lungs to gills, legs to fins, arms to wings, complete changes in respiratory, nervous and cardiovascular systems. Changes in brain connections, bone structures, muscles, tendons and ligaments ect.
Is that degree of shape difference necessarily beyond the capability evolution?
Yes, minor changes may be just variations with the same species. So hair and skin color, eye color, sizes, shapes of heads such as longer chins or flatter noses, ect are all variations within a species. Variation can be great and cover large changes as well. There have been many cases where scientists have mistaken the variation with a species and made that variation into new species as with the skulls at Georgia. So there is a fine line between what is variation with a species and what evolution claims is new species. Even fossil finds that may look exactly the same as another creature but is found in an out of place layer will be turned into a new species rather than consider that it was the same species that never changed. Yet we see many creatures who have remained the same for millions of years.
A haul of fossils found in Georgia suggests that half a dozen species of early human ancestor were actually all Homo erectus.
http://www.theguardian.com/science/2013/oct/17/skull-homo-erectus-human-evolution
How does this account for the structural commonalities between different types of creatures? How does it account for the
laryngeal nerve of the giraffe, or the
retrograde path of the vas deferens from ball up, over the ureter, and back down to the urethra? etc.
I dont know I'm not a biologists to go into that level of detail. But the structural similarities between different creatures can be just a common design. If everything is based on the same blueprint or building blocks for life then we would expect to see similarities even in unrelated animals. Evolution calls this convergent but we are seeing more and more convergent evolution. We are finding unrelated animals with large chunks of the same DNA in each. How does evolution account for this. Maybe there is a lot more capability in our DNA than what evolution has given credit for. Maybe the so called junk DNA is able to switch on and off functions when needed. Maybe many creatures have similar DNA but only use what is needed. Maybe they can share genetic material more readily than we think.
There were millions of stages, and there are billions of fossils (and every fossil will be of an individual that is 'slightly changed' from its parents - who probably weren't fossilized); we've only found an infinitesimal number of all fossils (and the oceans probably cover the remains of millions of species we'll never see).
But we still dont see that graduation now or in the past. What we see is well defined creatures that are individual and not blended. What we find are lots of gaps in the fossil records. We see a lack of gradual structure change. Evolution will hold up an example of transition between two animals like Archaeopteryx but its well defined and its the only one. There is nothing in between. If Archaeopteryx has fully formed wings then where are the 100 other stages getting from no wings to fully formed wings. They show the gradual transition from ape to human.
But all they are doing is taking the variations of apes including extinct ones and picking out the best that suit that gradual change. Then they will do the same with humans to make a nice linkage of transitions. But why can they do that with every animal and line them up. They seem to have no difficulties find the ape men but always claim its hard to find fossils for the rest.
Think about it at the population level rather than individual mutation level (whether a mutation is considered beneficial or not isn't as simple as it seems; see '
The population genetics of mutations: good, bad and indifferent'. The majority of mutations that come to term are relatively innocuous in themselves (see above) and fairly randomly distributed, so their effect tends to be a long term one; most are not clearly adaptive or maladaptive individually and in isolation. This is evident from current population statistics - estimates of human mutation rates are between 70 and 160 per generation (i.e. per individual), but sickness from genetic causes is age-related, from about 5.5% of the population by age 25, and rising to around 60% in later life including diseases with a genetic component.
From what I have read mutations are mostly a cost to fitness even the beneficial ones. Everything comes at a cost because basically you are changing what was already good. So to say that a harmful error is part of the driving force for more fitter and complex creatures seems illogical and against the evidence.
It's also fairly obvious that major structural changes are far more likely in simpler, less specialised organisms, than more complex & specialised ones, and genetic 'cross-talk' is likely to be more frequent and more significant earlier in the evolutionary tree. Horizontal genetic exchange is just another means of variation, subject to natural selection like any other.
If all life was microbe to begin with and a microorganisms can freely exchange genetic material wouldn't that mean that all life had access to all the genetic material and has continued to have access as it has become more complex. Also 95% of all life is microbe anyway so if anything complex life would be a small offshoot of a bigger forest or bush of life.
I'm beginning to feel like Dr Johnson, who said, "Sir, I have found you an argument; but I am not obliged to find you an understanding."
I just pose the questions and challenge the general consensus of evolution. But it seems I'm not the only one.