lpetrich

jtb: Incorrect. There are at least TWO explanations that I'm aware of. One, that the evolution of the Hox genes made it easy for diverse body plans to appear at this stage. Two, that the formation of hard body parts (and, hence, more fossils) became easier due to a change in the chemical composition of seawater at this time. Both could be correct, of course.

Ed:
There is no empirical evidence that Hox genes even existed at that time since we do not have fossil DNA. Any evidence for the seawater assertion?

The presence of Hox genes is inferred with the help of standard methods of evolutionary biology. In fact, it's even possible to reconstruct what the likely Hox genes were.

(bilateral to radial symmetry in echinoderms...)

Because chordates (bilateral symmetry) supposedly evolved from echinoderms (radial symmetry). This is basic evolutionary biology.

A subject that His Eddianness has a lot to learn about.

Chordates did NOT evolve from echinoderms. Both evolved from a sort-of-chordate ancestral deuterostome that also produced hemichordates (acorn worms).

This common ancestor was bilaterally symmetric, a feature shared by all of Deuterostomia except for adult echinoderms; echinoderm larvae are bilaterally symmetric.

One theory I've seen goes like this:

Many marine invertebrates do indirect development, where the adult is not much like the larva. In "Type I" indirect development, the larva grows a tail that becomes the adult animal. However, echinoderm larvae grow not one, but five tails, and these become radially arranged.

For more, see Early Animal Evolution -- yes, about the Precambrian.

Jack the Bodiless

You measured its position relative to the back teeth, Ed. What matters is its position relative to the brain case.

And do you actually know what the terms "facultative bipedalism" and "obligate bipedalism" mean? "Faculative" bipeds have the facility to walk upright, "obligate" bipeds are obliged to walk upright. Try walking on all fours, with your hands and feet (not your knees) on the ground, and you'll see that the problem is limb length, not the position of the foramen magnum.
Good. Therefore you cannot cite a lack of pre-australopithecine fossils as a "problem".
There is no "above" in which you explained what a transitional form between "facultative bipedalism" and "obligate bipedalism" should look like. Explain why Homo Habilis does not qualify.
No, we don't have fossil DNA. How is this relevant to the validity of the theory?
DID CHANGES IN SEAWATER CHEMISTRY PLAY A ROLE IN THE CAMBRIAN EXPLOSION?
No, they do not.

On Day 3, God creates grass, herbs and trees. These came AFTER the Cambrian Explosion.

On Day 5, God creates birds and whales. These came AFTER the Cambrian Explosion. God also creates "every living creature that moveth, which the waters brought forth abundantly, after their kind": i.e. all marine organisms. Most of these, including ALL fish, came AFTER the Cambrian Explosion.

On Day 6, God creates land animals. These came AFTER the Cambrian Explosion, but BEFORE the birds and whales created on Day 5, and BEFORE the grass on Day 3.

Again, why do you bother to post easily-refuted nonsense?

Oolon Colluphid

Are you suggesting then that these creatures did not have genes at all?
Or ‘merely’ that their genes worked in some radically different way from modern ones?

In either case, please give your reasons.

Why is it not a perfectly reasonable inference to think that genomes then worked in similar gene cascades to present ones?

And hence, pray tell which ‘kinds’ there are in the Burgess shale. If a kind is present back then that is still present now, why and how did their genomes so substantially alter their modus operandi to how it is today? And would that not be evolution?
Jack, I’ll go into a little more detail on one point if I may...

According to the bible, angiosperms -- flowering plants, “grass, and herb yielding seed after his kind, and the tree yielding fruit” -- were created on Day 3 (Gen 1:11-12).

Now Ed, you will find that grasses and fruit trees are angiosperms.

If Day 5 = Cambrian explosion, where is all the Cambrian (or even precambrian) angiosperm pollen? It is bloody everywhere after the end of the Jurassic. But nowhere before that. And the end of the Jurassic is three hundred and forty million years after the Cambrian. Why no trace of it in that all that time, if these plants were created before most animals?

To be sure, pollen of sorts is found earlier than that, but it is from gymnosperms. From here:
So:

(1) Pollen is fairly easily preserved, and hence it is widespread in the fossil record.

(2) Pollen, but still not angiosperm ‘proper’ pollen (ie from grasses etc), is around from the upper Devonian. That, dearest Ed, is still at least 140 million years after the appearance of animals on Day 5. Not before, as being created on Day 3 would predict. In other words, there is not a trace of such plants until well after Day 5.

Please explain how the biblical Days match.

TTFN, Oolon

Doubting Didymus

Perhaps the pollen all floated to the top layers of the flood sediment? You don't see pollen further down because it all floated upwards into the jurassic, along with all those light airy floaty bobbing colossal dinosaur skeletons.

Ed

Yep, but they are still crocs and iguanas.

Ed

Yes, but they did not evolve from crocodiles. Also, they are not as specialized as whales, ie they still had pelvises and did not have a highly specialized breathing apparatus(blowholes) and etc.

Quote:

Ed: Hippos don't have hooves, those are called toenails. Ungulates have hooves. Also ambulocetus has a fully developed pelvis, there are no transitions from a fully developed lpelvis to no pelvis in whales. And grippers are neither legs nor fins. jtb: Hooves ARE toenails.

Technically yes, but morphologically they are quite different. With toenails the toe pad still has contact with the ground and could contain webbing to aid swimming, but with hooves only the hoof touches the ground and there is no place for webbing due to the large size of the hoof so they are not made for swimming.

Quote:

jtb: And where did you get the notion that whales don't have pelvic bones? They DO have vestigial pelvises! And there are transitional forms which cover that. Are you just making this up as you go along?

No, last time I saw a whale skeleton they did not have a true pelvis. Evidence they have a true pelvis?

Quote:

Ed: True hooves are not very good swimming tools. And toe nails are not hooves. And see above about that well developed pelvis. jtb: Falsehoods don't magically become true by repetition..

What falsehoods? See above.

Jack the Bodiless

They evolved from land reptiles, and filled the "fully aquatic air-breathing carnivore" niche. A mosasaur would have regarded an ocean-going crocodile as a tasty snack: crocs couldn't have evolved to occupy the mosasaur's niche while the mosasaur was still around.

Afterwards: ambulocetus had a significant advantage over the croc, being warm-blooded. Handy for maintaining vigor when swimming out into deep, cold water to hunt.

And, yes, icthyosaurs did have blowholes. So you're making stuff up again. You do this by reflex?
Of course there is! Ambulocetus had little hooves on each toe. Plenty of room for webbing between the toes.
What is a "true" pelvis?

Ambulocetus had a true pelvis, with legs attached. So did basilosaurus, but the pelvis and limbs could no longer be used for walking. Modern whales have lost the legs and have a vestigial pelvis. Transitional forms, Ed: and there are plenty more between those. What more can you possibly want?

It is a falsehood that ambulocetus hooves would make it a poor swimmer, a falsehood that whales don't have (vestigial) pelvises, and a falsehood that there is some sort of uncrossable gap between ambulocetus and modern whales (and we have the transitional fossils that bridge that gap).

A few names to search for: Pakicetus (50 million years ago), Ambulocetus (49 million years ago), Rodhocetus (46.5 million years ago), Procetus (45 million years ago), Kutchicetus (43-46 million years ago), Durodon (37 million years ago), Basilosaurus (37 million years ago), Aeticetus (24-26 million years ago), Squalodon (16 million years ago), Cetotherium [early baleen whale] (15 million years ago), and Kentridon [early dolphins] (15 million years ago).

Where is the gap, Ed?

Oolon Colluphid

Oh no you don’t Ed, you’re not getting away with that little switch-around.

Evolution predicts that a formerly-land-dwelling creature, heavily modified to a watery existence, might exhibit some sign of a pelvis.

Creation says that each thing was created to fit its circumstances.

So whether a modern whale’s anatomy contains a ‘true pelvis’ is irrelevant. Of course it does not have a ‘true pelvis’, because true pelvises are used by land creatures for locomotion with legs. A whale is not a terrestrial critter, so why should it have a ‘true pelvis’?

What you need to explain is, why a creature designed by god for life in the sea should have any sort of pelvic bits at all. Why are those bones there, and why do they resemble bits of pelvis?

To reiterate for emphasis:

A whale is not a terrestrial critter, so why should it have anything even slightly like a pelvis?

TTFN, Oolon

Oolon Colluphid

Ed, what counts as a ‘true pelvis’? Might it have bits like this associated with it, perhaps?



But look at it in proportion to the rest of the animal. It's the bit at the back, btw.



Please state why this is not vestigial -- or a damned stupid thing for an intelligent designer to give a sea creature.

TTFN, Oolon

Duvenoy

Ed, you're starting to sound like Kent Hovind. Shame on you!

Of course they're still crocodiles. I briefly described them in answer to a question (your's, if I'm not mistaken) as to why crocs didn't evolve into whales, instead of some land mammal. If you can come up with an explanation as to why they might be well suited for future whaledom, I'd be interested, nay fascinated, to hear it.

The Galapagos marine iguana is another kettle of lizard. Yes, it is still an iguana, but one that has lived in isolation for a very long time. Thus, it is evolving away from it's original form. NO other terrestrial reptile has developed feeding habits similar to this one: diving several feet deep into cold water to eat algae from the rocks.

Along with the algae they ingest a downright posionous amount of salt. This, they seperate and expel through their nostrils. Show me another ig that can do this.

Do some research, Ed. Compare the marine ig with all others, remembering that one of the other species was the immigrint that colonized the Galpagos. Then come and tell me all about it.

doov