aseee wrote:
Mutations are not necessarily fatal. There are highly conserved proteins across species (histone proteins involved in DNA replication, metabolic proteins) which, when mutated, often result in death in utero. These are so-called essential genes that all DNA containing organisms need for survival. However, there are many lesser conserved proteins which are species specific and result in phenotypical traits. I don't see how anyone with an understanding of molecular biology can say that evolution does not occur at least on a microlevel (within species). I agree making a jump to the macro level is more difficult to conceptualize, but is not out of the realm of possibility.
Just FYI, no one says there is not micro-evolution. Creationist, Intelligent Design, Darwin skeptics, Darwin proponents, nobody is debating micro-evolution.
Also, you said lesser conserved proteins which are species specific. Did you mean genus or family specific? If the proteins are species specific, then they are called novel proteins, or orphan genes, and they show no connection to other lifeforms in a common ancestry phylogeny.
If you meant genus or family specific, that doesn't necessarily imply common ancestry, it can also just be a design feature. All cars and motorcycles have engines. All cars have windshields. Only some motorcycles have a type of windshield. Does this mean that motorcycle with windjams are more closely related to cars?
I only bring up the example of cars and motorcycles to demonstrate that placing objects into categories based on common features does not necessarily prove closer ancestry among those object that share more features. It can be completely based on the design choices of the designer. Even though lifeforms perpetuate their existence through ancestral generation, the common or disparate features between life forms does not necessarily imply common ancestry.
In macro evolutionary theory, the assumption of common ancestry is first made, and then the lifeforms are categorized accordingly. The categorization itself does not prove common ancestry. It is an assumption used to analyze the data. This assumption is at play whether you are look at visible phenotypic features, or you are talking about proteins common to all living cells, or only common to cells within a subset of lifeforms.
Common ancestry is assumed, and never proven in Darwinian evolution.