Evolution and Increased Diversity

Yes, I got it, like a holy shitball smack in my corpus whatever. But I've already agreed to that. Now, please tell me this: If you let loose a population of microorganisms on the surface of a biofriendly Mars, would that population necessarily diversify without Mars' environment changing in any way?My answer: Not necessarily, if you can assume that those microorganisms would have no effect on Mar's enviromnmet. Can you assume that?”HM

Yes.

Okay, good. Phew *wiping brow*

No, not necessarily. I could or it could not. Sure, but I also think it is possible for them to have an effect on Mars's and still not diversify. It depends on what effect they have.Who's Mar?

Why sweat it?

Why doesn't it also show that the extant biota and its potential for evolution also favored an increase in biodiversity?”HM

The statement could use some nitpicking if it were being used to communicate actual deep time events. As things stand though, no worries.

It does. It just doesn't show that its necessary.The extant biota tends to diversify.

I agree. (But, oops, people who live in glass houses, you know.) With or without evolution?”HM

Morphological similarity is evidence that two vertebrates did similar things, but it is only one line of evidence, and it can point you in an erroneous direction. That Ambulocetus has a crocodile-like morphology absolutely does not in and of itself make it obvious that the two competed in the same niche. I'm not really sure what pre-programmed means here but I think that I agree with you if what you're saying is that evolution will happen even if a niche is empty (say in a post-disturbance situation). What are you talking about? Once what? Really? When exactly was this? I'm gonna call for some citations of scientific papers here.

With evolution. How could they diversify without it?Genetic mutations randomly provide "opportunities" for diversification, but it depends on a selective pressure for those opportunities to take hold and have an effect.

Reading this thread, I find what appear to be these particular issues--a/ is biodiversity, [i.e., 'variation'in bioform and behaviour], a constant or a variable, and if a variable, than the effect of what specific cause?
b/is the amount of 'biodiversity' in the biosphere inconstant and variable in the short term,[say minutes to millions of years], but deterministically expansive over the long term, i.e., the entire 'lifespan' of planet earth?
c/can "Natural Selection" account for either fluctuations in the amount of biodiversity, both positively and negatively, in not only circumscribed localities, but even in the biosphere as a whole, and in both the long and short term?
d/ can "Random Genetic Mutation" do that?
e/ can "RM+NS" linked together, do that?
f/ is the extent of biodiversity, either short-term or long-term, an adaptationist [NS], or a stochastic [RM], or a mechanically/divinely predetermined [mechanist/creationist], effect?And in passing, I would note that any creationist who denies evolution and claims that all bioforms were created, ex nihilo, by 'god' on a given 'day', must, in view of subsequent 'floods', 'fires', 'plagues' and other 'acts of god', see that biodiversity would have to have been steadily _decreasing_ in overall extent since that time.
To admit of an increase in biodiversity over time is to admit the reality of evolution and the irreality of biblical literalism. Thus YEC creationism must be fundamentally different from OEC creationism, which would hold, if I understand it aright, that evolution does take place because the impulse to diversify and vary was 'built into', [i.e., predestined, predetermined, pre-programmed into], the 'original' lifeforms by a supernatural programmer, and so diversity and variation must, deterministically, [as a matter of 'predestination'] _increase_ over the long-term, i.e., the lifespan of the biosphere as a whole.

Wow, that is difficult to read. It's a variable caused by natural selection. Not necessarily but things have tended to be that way. Yes, as long as there is random mutation (or some other source of variation). No, it provides the opportunity for diversity but you need the selection to actually get the diversity. Yes. Couldn't it be predetermined and adaptionist? Its not stochastic. Thus the point of this thread. The ToE does not necessitate a long term increase in biodiversity, therefore we can determine that this is not what was predestined. That's not to say that the fluctions we do see are not what was predestined, but then anything could have been predestined in that sense.

I do like this one, RADZ. It reminds me of a line from a county-western song: "There ain't no safer sex than the sex I ain't having with you."I think I see your point about randomness...maybe something like the random walk idea. Do I copy you correctly by saying that if a single species of bacteria were to be placed in sterile but fertile environment the only thing it could do evolutionarily would be to diversify. Otherwise it's extinction.”HM

Or stasis.It could thrive and not evolve and not go extinct.