Originally posted by randman
I am certainly not an expert on genetics, but have waded through some articles on both sides of the issue, some of a technical nature, but I do understand that in a argument, one side has to prove a positive, or try to, before they can egitimately demand the other disprove it.
Ok, when I get ready to make a positive statement about microevolution having led to macroevolution I will do so, and I will probably make the point that microevolutionary changes have no known limiting factor.
The issue is existing potential. Evolutionists must show that mutations
Mutations have been proven to happen.
can add to that potential
Mutations have an impact on the phenotype, and depending on the environment, those changes can be adaptive, and this has been shown.
Most of the mutations don't major in the liberal arts, so this phrase can go in the can.
Provided a change is selected for it remains. Nothing prevents future changes from occuring, therefore they can add up...
to macro-evolutionary changes.
And if we don't know of any mechanism that prevents them, there is no reason to assume that microevolutionary changes cannot add up until they reach a scale that is macroevolutionary. Thus the inference of macroevolution from microevolution is not unreasonable absent a limiting mechanism. This thread demonstrates that the inference is a reasonable one, the other demonstrates that there is evidence in support of the inference.
The limits then, the mechanism you ask for, is the same mechanism for change, the existing genetic material.
Mutation is the mechanism for change. Mutation is change to existing genetic material. What, exactly are you saying?
The question is if evolutionists have shown how that genetic material can add genes in a manner to produce macro-evolutionary changes.
Genetic material was never postulated to add genes. Evolutionists have shown that descent with modification occurs. Evolutionists have even shown that mutations can add genes or chromosomes, or change genes that are already there. The production of macro-evolutionary changes is what is at issue, so I will save that for the other thread... I just wanted to make sure there wasn't a mechanism that prevented it that someone knew about.
Think of it like rocket propulsion. Rocket propulsion has definite limits on speeds that can be acheived. It is true that technological advances give us greater and greater speed but there appear to be limits on this type of propulsion. However, creatiing a space-time bubble theoritically could overcome those limits. Evolutionists haven't demonstrated that mutations are sufficinetly unlimited in potential to create all of life.
I think I will think of it like descent with modification, and go from there.... the rest is just obfuscation by analogy.