furmious,
first of all, i want to commend you on your civility.
you are one of the most civil people i've debated in a very long time.
you seem to understand perfectly my meaning, while others go into the "define it" mode.
for that, i graciously thank you.
second is that name of yours, it conjures up all sorts of wildness.
Just naturally skeptical, I guess. It sounds like publicity or media blurb, not the same tone or import as the article.
believe me, i understand the naturally sceptical bit.
also, i believe i've seen this very same article posted on respected sites.
Strictly speaking, nothing is ever proven in science; we just have levels of confidence. Multiple independent lines of evidence, a simple, elegant explanatory mechanism, and no plausible evidence for alternatives, make common descent more than an assumption - it's beyond all reasonable doubt.
i understand this too.
science is not a method of proof, but of discovery.
also, it's a method of elimination, eliminating contenders until you arrive at the only thing left.
It's not a binary choice. Mutation rates are relatively constant (though they do vary), but selection pressures vary directly with environmental changes. This implies that environmental disruption will be a powerful driver of evolution. When you're dealing in clock ticks of millions of years, what is and isn't gradual is relative.
maybe.
the ability of the genome to adapt negates a large part of this.
What was accomplished? how many mutations in how much time make a major change? A single mutation in a regulator gene can produce major changes, like an extra pair of legs, or eyes, etc., but major phenotypic changes of that kind would generally require an available and compatible niche to have a selective advantage, so would be more likely to succeed in times of environmental change, when new niches more are likely to be available. So you might expect major developments to correlate with environmental upheavals - which is what we see.
this is one of the most befuddling aspects of evolution i've run across.
we talk about genomes (basically DNA), and the corresponding changes to it (mutations).
then we go into phenotypes, where the previous argument doesn't correlate.
in my opinion, this is an attempt to confuse the issue.
Not really, it's the same underlying mechanism, with different contributions from the different drivers of selection, over varying timescales. As I understand it, the debates and arguments are about the mechanisms that generate selection pressures.
not according to smith.
these transitions were few and major.
furthermore, it seems they are "mechanical" in nature instead of mutation driven.
granted, some of these transitions probably happened by HGT, but again HGT can hardly be called gradual.
i seriously question the "gradual accumulating changes", in regards to macro evolution, for 2 major reasons.
first it has been mentioned by at least one scientist.
second, and more importantly. is gene mutation by HGT and base insertions.
these 2 processes would negate any "accumulating"
You need more than a guess. To be taken seriously, you need a plausible model that predicts and explains the observed gene frequencies and distribution, and does it better than current models. HGT is an important factor in prokaryotes, but not so much in eukaryotes; if you want to show otherwise, you'll need find some solid evidence for it, or at least, a well-reasoned and testable argument for it.
i don't buy this line of reasoning, and the apparent presence of ERVs in humans is the reason.
if HGT is not that frequent in humans, then these ERVs had to come from deep time, and they would be present in every lineage from the moment of acquisition.
to my knowledge, this has not been proven.
yes, it appears this has been shown between ape and man, but that's it
for example, it hasn't been shown to exist between lungfish and apes (reference the TOL upload for source, post 405.)
so no, common ancestry has not been empirically proven.
i use common ancestry in the macro evolution context.