Neruda

I would like to add that when the dinos went extict, it was partly because they were too fit. They worked great as long as conditions remained the same, but they lacked the flexibility to survive a major crisis (like an asteroid). In situations like that, it's usually the less-fit animals, the odd balls, that survive. (I might be off on some of that, so anyone feel free to clarify if necessary).

Doubting Didymus

Hmm. I would not think that 'survivability in a range of environments' would become part of a large organisms genetic makeup, unless the population had to spend time in multiple environment. There would not be any genetic benifit for the dinosaurs to have had genes that help them survive a post-asteroid world, and that's even if one did just happen to chance on one.

In the case of the large dinosaurs, I think the main factor was the amount of food they had to eat, so it may have been more the fact that mammals were small at the time, and did not have to find as much food post - apocalypse that pulled them through. Remember that some 'dinosaurs' pulled through, particularly the small ones (crocodile precursors) and the dinobirds.

I also don't think it would be very probable that any organism might 'oddly' (i.e. by chance) have a mutation that makes them survive asteroid collisions (and post collision environments). I would say that it was simply luck and timing that let the mammals take over.

Oolon Colluphid

Uh-huh. And “gravityists say”, “relativityists say”, “plate tectonicists say” and “atomists say”? I think you mean scientists. In this case, it’d be groups of them such as palaeontologists and anatomists.

The -ist ending is applied to studiers of subjects; it is not normally applied to proponents of scientific theories (because to get to the level of Theory, an idea has to be so overwhelmingly supported by evidence that it is pretty well universally supported amongst those who study that bit of the natural world.)

When -ist is used, it's usually by opponents of the idea, normally those so poorly informed in the subject that they've no idea what they’re talking about. They use it to imply ‘belief in’. That ain’t how science works. Faith isn’t involved, evidence is. Hence, many evolutionary biologists take great exception to being called ‘evolutionist’. So by using the term, you sure sound like a creationist.

Do you think that if it really were a problem, the folks who spend their lives studying this stuff might not have noticed by now?

Huh?

Do you mean, after the dinosaurs were gone? And I hope you mean into the niches -- large animals -- rather than into actual dinosaurs?

Lizards had spent millions of years evolving to fit their own niches, developing their own tricks and ‘designs’ for getting by in their circumstances. They shared a common ancestor with dinosaurs, which means that at one time there was a population of creatures, all potentially interbreeding; they became divided, and some went on to become lizards, others went on to become dinosaurs. They both became different from the common ancestor, even though one group, by staying in more similar lifestyles to the ancestral species, remained overtly more similar to it. Ancient fish, for instance, are not modern fish; therefore, if there were no land tatrapods, modern fish would not produce the same land animals as the common ancestor went on to do.

If you start from a different morphology, you won’t further down the road get to the same morphlogy that soomething else led to. Despite sharing a common ancestor, mammals didn’t evolve into nocturnal birds, they evolved into bats; they didn’t evolve into ichthyosaurs, they evolved into dolphins. Since dinosaur-contemporary lizards were not the same things as the common ancestor they shared, they wouldn't have evolved into dinosaurs 'again', even if the opportunity arose.

Okay, so why didn’t lizards more generally evolve to fit the dinosaur-vacated niches? Because mammals beat them to it, probably. Bear in mind that mammals have a variety of physiological advantages over lizards for many niches, such as warm bloodedness. One could argue that dinosaurs kept lizards in their place (or out of theirs) by having some degree of homeothermy; but there’s no doubt that mammals exploited (still exploit) so many nocturnal niches because of their warm-bloodedness. Whatever else though, there was probably an element of luck too. An ancestral population of mammals was in the right place at the right time. What we got was not sixty-foot Komodo dragons, but baluchitherium.

? You and me both. I’ve no idea what being ‘very fit to survive’ means or has to do with it. There are niches available for exploitation in the category of ‘large animal’. One group had a very good shot at it, another group is having another go at filling the variations on those niches. So? If you mean the dinosaur type of living was viable, then sure. And another lot are (or were) filling it now.

That’s cos you’re .

Magazine, I see from your profile that your interests include, unsurprisingly, magazines. May I suggest New Scientist and Scientific American, then dip into Nature and Science...?

You could also diversify into 'books'.

Cheers, Oolon

[ September 24, 2002: Message edited by: Oolon Colluphid ]</p>

Oolon Colluphid

Hi Neruda

Sorry, no such thing. I think you mean too specialised. Specialised species are more prone to extinction from upheavals, obviously. If something strikes down a particular wasp species’ fig, then it’s stuffed. It is generalists which have a better chance in such circumstances. However, dinosaurs were a very diverse group of creatures, from chicken-sized bipedal predators to vast quadrupedal herbivores. How might an entire group be too specialised, and do you have any evidence for it in dinosaurs?

I don’t see how inflexibility could have anything to do with it. Just how flexible would you have to be to survive stuff like a bloody great rock coming out of the blue (literally)? Evolution does not forward-plan; organisms only have features that are beneficial in the here-and-now. And they get them by their ancestors having encountered the relevant circumstances rather a lot. So nothing is going to have genes to survive massive impacts -- unless impacts were an annual phenomenon!

Fitness is only relative, it cannot be absolute. And what it is relative to is the environment, including all the other organisms in the species.

Are we talking individuals, or species? If individuals, I guess what you mean is that when new opportunities open up, ‘sports’ may get a crack under the new world order. Sure. But so might members of a generalist species. Remember that ‘nature does not make leaps’: an odd individual will still have to be part of a breeding population, because it is populations that do the evolving.

If you mean species, I’m not sure what an oddball species might be. Each is adapted to its niche. And most of the really odd creatures I can think of are... specialists! Their specialising adaptations is what makes them odd. Murid rodents aren’t particularly odd; naked mole rats are!

The only oddball generalist I can think of is Homo sapiens.... and again, it’s our oddity, our relatively vast brain, that is the cause of our ability to be generalists.

Hope that makes it clearer (?)

Cheers, Oolon

Duvenoy

Oolon has said it better than I could.

Very probably, but it is highly unlikely that any would evolve into 'dinosaur-like' creatures. Lizard skeletons are vastly different from the dinos. Those that have legs (most, but some don't) sprawl out on the ground. Dinos stood with their legs directly under them. Also, no lizard has ever been found to be bi-pedal, although some few of them such as Basilisks, Collard, and Frilled Lizards will run bi-pedaly for short distances to escape predators or chase away a competitor. They're pretty damned fast, too!

Could they evolve into bi-pedalism? Doubtful, I think. Their pelvic structure is wrong for it. I think they'd continue to scuttle, rather than walk.

Something to think about: what conditions would favor reptiles, for the most part pretty specialized, over mammals? And how 'bout amphibians? They live comfortably in a varity of conditions. Perhaps something entirely new might evolve from a frog.



doov

MarcoPolo

What's the deal with this whole 'ist' thing? Look in most dictionaries and it's there? Heck, I just went to Dictionary.com to see what people cry about and found this:

evolutionist

\Ev`o*lu"tion*ist\, n. 1. One skilled in evolutions.

2. one who holds the doctrine of evolution, either in biology or in metaphysics. --Darwin.
Source: Webster's Revised Unabridged Dictionary, © 1996, 1998 MICRA, Inc.

Apparently it's a real word after all. And I would guess that when people use the word, they are simply grouping everyone that 'holds the doctrine of evolution.' That could be non-scientists as well I would assume.

[ September 24, 2002: Message edited by: MarcoPolo ]</p>

Oolon Colluphid

Thanks Doov, but that was DD!

PS Doov, browsing through Greene’s <a href="http://www.amazon.com/exec/obidos/tg/detail/-/0520200144/qid=1032885561/sr=8-1/ref=sr_8_1/104-3870277-3042310?v=glance&s=books&n=507846" target="_blank">Snakes: the evolution of mystery in nature</a> the other day, I came across the fact that colubrids have glands involved in venom secretion called Duvernoy’s glands. Any eponymous connection there? (And if so, you’ve mis-spelled your handle )

Oolon

Oolon Colluphid

Ay-oop, Marco Polo rides in with this, looks like it’s time for me to do some high horse ridin’ of me own...

Actually, it didn’t bother me greatly till now, but I’ve seen it piss off Peez for instance, hence bringing it up. But now it pisses me off too, for the reasons below.

The point of dictionaries is to define words in common usage, so I’m not overly surprised.

And therein, as I said, is the reason for objecting to it. We’re talking science, remember. Again from Dictionary.com:

<a href="http://www.dictionary.com/search?q=hold%20to" target="_blank">Hold to</a>: “To remain loyal or faithful to”.

<a href="http://www.dictionary.com/search?q=doctrine" target="_blank">Doctrine</a>:

“1. A principle or body of principles presented for acceptance or belief, as by a religious, political, scientific, or philosophic group; dogma.”

Cambridge Dictionaries Online has: “doctrine: a belief, theory or set of beliefs, esp. political or religious, taught and accepted by a particular group”.

In science, nobody ‘holds to’ ‘doctrines’. They accept or reject ideas on the basis of evidence. Sure, ‘doctrine’ could be used as refering to the body of scientific knowledge. But as I said before, it is normally used as if evolution is a belief, a faith, something akin to religion. It is not. You don’t believe it, you accept it because to do otherwise in the face of the evidence is simply perverse.

So what? Nobody’s questioning whether it’s real -- hell, neologisms are welcome anyway! -- but what the damned word implies. According to CDO, nigger, kike and honky, shithead, wanker and dickhead are also all real words. Nobody objects to their mere existence; they object to having them used about themselves. Ditto evolutionist. It is an insult to scientists.

As well?? Most people don’t think or care about evolution (beyond the very superficial) one way or another; most people are simply not that interested. Those who do understand science wouldn’t think to use it: (a) it implies a travesty of science, and (b) they won’t have read it in any normal science context. It is only one specific group of non-scientists, who are critically brainwashed and terminally ignorant (creationists), who ever seem to use the term.

If someone strongly opposed to what you are and do uses a (mildly) offensive term about you, should we not take (mild) offence? No? What are you, an idiot?

TTFN, Oolon

theyeti

You are correct, but these are examples of convergent evolution, which as I explained, are nonhomologous. One good example are the various marsupials, like the recently extinct marsupial wolf and the long extinct marsupial lion. They resemble placental mammals, and they occupy the same ecological niche as their placental counterparts, but they are not the same

theyeti

MarcoPolo

It actually depends on my audience or who is doing the mild offence. If I know they don't know what they're talking about, therefore not aware that they are being offensive, then I give them a break and just go on knowing what their intent was. If it's someone I know is just badgering me into an argument, I'd handle it the way you did.

I see now that I may have inadvertently offended you with my question. It wasn't my intention.

I was just curious why the word was offensive. It's been brought up several times and I just thought I'd ask!!

Also, I don't consider myself a full blown idiot, but the jury is still out on that. <img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" />