Kurieuo wrote:Aren't you saying the same thing I am, but only in different words?
Hard to say. For example, your earlier comment about "[drawing phenotypical conclusions] which may/may not be correct in actuality
" is vacuous. "Is Jesus divine?" "Maybe, maybe not."
I think you've ripped matters out of context. From past discussions, you've seen "nested hierarchies" as evidence for natural evolution and common descent. Perhaps if you flesh out exactly why this is so. I'm not saying it's not, but neither as you should know if you recall some of our exchanges, do I think it conclusive like you seem to.
Kurieuo wrote:You're trying to lead here with questioning I don't really understand or get the purpose of.
I was waiting for you to address any of my questions about your views against common descent.
Morny wrote:For example, how is your question about "what is a species?" relevant to the nested hierarchy evidence for common descent? Do you agree that any reasonable sub-grouping of dogs, coyotes, and wolves doesn't affect any other grouping in the nested hierarchy?
Ok, now you've given questions. How are "species" relevant to nested hierachies? If we're talking about all extant species, all sharing a common ancestor, then it makes sense we should be able to trace them back via direct lines. The picture however, isn't nearly that neat. Rather, more like bushes, and then not even that, more like nodes on a web.
This does rule out natural evolution, but it does to me seem unlikely that all life shared a common ancestor. Common building blocks, of course, noone questions that. But, I don't see any reason why everything must be related at some point going back, rather than there being multiple origins. In both instances, I think these "nested heirachies", which you believe prove common descent, would be diagramable under both scenarios.
Kurieuo wrote:A foremost geneticist (Craig Venter) disagrees with the idea that we have a common ancestor, and the tree of life which he considers to be an artefact of early scientific studies that are no longer holding up with knowledge we've gained from deep sequencing of organisms.
Venter supports common ancestry for almost all the organisms on that nested hierarchy ("tree of life") picture, e.g., that we share a common ancestor with fish and worms.
Venter's video argument is actually about whether, 2 billion years ago or so, the "tree of life" was actually "bush-like". That long ago, no plants and animal existed - not even one celled organisms with a nucleus. What did exist were one celled organisms that routinely laterally transfered genetic material to each other, instead of through cell division. Hence Venter's use of the term "bush-like".
Venter also pointed to mycoplasmas (one celled bacteria without a cell wall), which for a while didn't seem to fit genetically under the "bacteria" sub-group in the nested hierarchy. But with ever improving genetic research, even mycoplasmas now appear to be hierarchically related to other bacteria types, i.e., mycoplasmas do not need to be specially or independently created. And with more new evidence, support for Venter's outlier views on these details against common descent is diminishing even more.
You may/may not
be right. Venter doesn't deny evolution, but from listening to that talk and other discussions from him, I get the impression (and have been misled even by reading into his own words) that Venter actually doesn't believe in a traditional evolution tree of life scenario. The fact Venter says that the tree of life doesn't really hold up. When heat is applied, he then concedes that "there may be a bush of life...
" offering some relief to those participating on the panel. Getting some traction, he then diverts the topic in that direction to discuss different domains that are DNA-based. We'll find the same molecules and base systems wherever we look, the implication of Venter's words being that doesn't mean all life is "related".
Dawkins also picks up on this, questioning why Venter calls the tree of life "a fiction
" (so I'm not alone in reading into Venter's words). And, then nervously questions Venter along the lines that our sharing all the same DNA and base does prove a tree of life, doesn't it? To which Venter stops and just laughs with the audience avoiding a response.
Now I don't know enough about Venter's views, I think he holds those cards rather close to himself, so you may be right. Certainly, he believes evolution happened, but I'm quite sure he doesn't believe all extant life as we know it is related. He targets the deeper "domain" level, nonetheless, I so feel (and Dawkins is rightly concerned) Venter was challenging the tree of life in general before backing off.