“Or are there genetically imposed limits to the amount of change which can take place?”
Yes there are. Genes are responsible for protein translation and contain regulatory elements, enhancers.
“Our major objection to the role of mutations in evolutionary change is the clear lack of data to indicate that mutations really accomplish anything new. While some weird-looking fruit flies have been created in the laboratory, they are still fruit flies. Bacteria are still bacteria.”
No one is making the claim that single mutations dramatically change an organism into something wildly different. However, inhibiting a single gene can result in the loss of function in an organ or prevent the development of a body part such as a limb. It can even go in the other direction. Laboratory studies on chicks reveal that single mutations can cause atavistic growth of teeth which were inhibited by another gene. This is a laboratory induced reversal of a loss-of-function mutation. We also have fossils of primitive birds possessing teeth.
Mutations change the amino acid. You may have ‘silent site’ mutations, moderately disabling, or lethal changes in the nucleotide sequence. They can have a variable effect on fitness, from highly advantageous to highly disadvantageous. Most mutations are simply neutral until another mutation causes a significant change in the amino acid sequence. The advantage of any mutation will depend on the affect that any corresponding morphological change has on the organism’s niche. If there is no morphological change, that that will also affect survivability.
One example is the decline in mean viability in Terumi Mukai (et al) Drosophila (fruit fly) experiment. Another is the changes of fitness effects of single mutations isolated in experimental populations of E. Coli and yeast. Also, many mutations are pleiotropic (affect more than one character).
Whether or not the mutations happened gradually or within a short period of time is an empirical question, not a theoretical one.
The end result of “fixing” advantageous genes in a population can sometime be that an existing structure is modified to gain a new function. For example, sesamoid bones often develop in connective tissue in response to embryonic movement. Such bones are the origin of novel skeletal elements, such as the extra “finger” of the giant panda and the patella (kneecap) in the leg of mammals, which is lacking in reptiles (Müller and Wagner 1991)
“Natural selection is a conservative process, not a creative one.”
Some genes are conserved, others are not conserved.
“First, virtually all taxonomic levels, even species appear abruptly in the fossil record. This, it will be remembered, is one of the sharper criticisms of neo-Darwinism, and one of the two cornerstones of punctuated equilibrium. It is relevant not only that the various levels of taxa appear abruptly but also that alongside the higher taxonomic levels there are unique adaptations. This is the key. Unique and highly specialized adaptations usually, if not always, appear fully formed in the fossil record. The origin of the different types of invertebrate animals such as the sponges, mollusks, echinoderms like the starfish, arthropods like crustaceans, and others all appear suddenly, without ancestors, in the Cambrian period.”
We are very fortunate to have the fossils that we have. Geological activity destroyed most of them. The significant data is not the number of intermediate fossils that we have but their location in rock layers. If you find a mammal fossil in pre-Cambrian rock then you have evidence that evolution is false.
There is much more to say. Shall I go on? Any questions?
[[No one is making the claim that single mutations dramatically change an organism into something wildly different.]]
That is NOT what the article stated- nowehre did it mention single mutaitons- as well, the fruitfly experiments involved many many millions of mutaitons, just as species woudl be subject to over their supposed billions of years of ‘evolution’
[[It can even go in the other direction. Laboratory studies on chicks reveal that single mutations can cause atavistic growth of teeth which were inhibited by another gene.]]
Swell- expression of info that is already present, and hten turnign that info on- Again you are NOT creating ANYTHING new via mutation- it’s a ‘johnny come lately’ attempt to, after the fact, look at the completed code, point out somethign that ‘changed’ (But hwich falls squarely, once again fully within species specific parameters, and claim it’s a ‘new and novel’ feature- which it certainly is not
As I mentioend before- when you CAREFULLY examine all the so called evidences for macroevolution, they break down- and hte article I pointed you to shows that NO new novel non species specific info ever arises, and certainly NOT in the massive- MASSIVE amounts and accumulations that MUST have occured IF macroevolution were a reality- ALL we have arte moot examples of species change, species change which falls squarely, once again, within species specific parameters-
[[Mutations change the amino acid. You may have ‘silent site’ mutations, moderately disabling, or lethal changes in the nucleotide sequence. They can have a variable effect on fitness, from highly advantageous to highly disadvantageous. Most mutations are simply neutral until another mutation causes a significant change in the amino acid sequence.]]
You don’t see the problem do you? ANY changes MUST be anticipated- in other words, the metainfo MUST first already be present- mind explaining how that metainfo arose from chemicals? Simple changes don’t just affect one aspect of a system, it affects many, and IF ALL the systems aren’t able to cope- then the changes won’t be assimilated into the whole- in order to cope however, the whoel system must have had the metainfo already present to regulate, direct, and utilize htese changes
[[The end result of “fixing” advantageous genes in a population can sometime be that an existing structure is modified to gain a new function.]]
And hten he goes on to show an ABNOMALITY such as an extra digit- for which the info was ALREADY present- Muller gives NO evidence for NEW non species specific info, morphology, or major organs or systems not specific to that species arising from mutaitons- He just A PRIORI ASSUMES they must have- ‘sometime in the past’, and is doing nothign more htan pointing to MICROEVOLUTION and claiming it is MACROEVOLUTION, or at least claiming such microevolutionary changes ‘could result in’ macroevolutionary changes ‘sometime i nthe past’ (For, once again, which we have NO evidence)
[[“Natural selection is a conservative process, not a creative one.”]]
Yup- but mind explainign to everyone how simple conservation can lead to NEW NON SPECIES SPECIFIC systems arising without hte info to do so?
[[There is much more to say. Shall I go on? Any questions?
]]
Hopefully it’s not goign to me just more examples of microevolution that is trying to be passed off as ‘evidence for macroevolution’?