Land Mammal to Whale transition: fossils Part II

I would also add that regardless of the morphology of the beasties, two species would be no more closely related (genetically) than, say, humans and any ancestor separated by an equal amount of time.An extant coelacanth and a Mesozoic one would be no more closely related than a human and the shrew-like mammals that existed at the same time.An extant cockroach and one from the Carboniferous would be no more related than a human and one of the earliest still-almost-amphibian-like amniote.

Really? How does that work out?I once went to a museum where they had the worlds oldest insect frozen in amber. Some 25 million years old. Anyway, the insect was an ant I belive. It was a long time ago, but if I recal, the tour guide said the ant was of an extant species.So, if we compared DNA from that ant to one of it's ancestors, would we see the same distance in "relatedness" as us and our 25 million year old ancestors?That's fascinating. I never knew this.

Well, I've read that the average "life-span" of a species is about five to ten million years -- I don't know what the variance is, but I'm not particularly surprised that a 25 million year old species is known.Most animal genomes consist of a large portion of non-coding "junk DNA" that would be free, more or less, to randomly mutate -- the so-called "molecular clock" -- I would expect that the genetic distances between this amberfied ant and a current one would be similar to that of a human and a late Oligocene "monkey" (note my use of the fancy word "Oligocene" in a desperate attempt to regain credibility).I admit that your example does appear, though, to weaken my actual point a bit.

Ok, but you'd better quantify the "millions" -- single digits I think is no problem.Beyond that the organisms are not the same or we can't tell AFAIK.If you have anything that supports the actual same species back beyond 10 Myrs I would be interested in it.This message has been edited by NosyNed, 08-12-2005 04:00 PM

Like I said, it was a long time ago. It may have been less than 25 mill, but It was up there in the millions. Still a pretty cool fact I didn't know about.Oh, and 10 pts. for using the word "Oligocene" properly in a sentance

randman has previously made the assertion that the fossil record for whales and their ancestors is fairly complete - 90% complete. Therefore the lack of "transitional" fossils observed within the current collection of fossils implies that there were in fact no transition events in the past.His assertion of 90% completeness seems somehow to be based on the concept of a generalised collector's curve and a statement that all extant cetacean families are present in the fossil record.Whilst I'm cautious about the application of a collectors curve to sampling over a wide geographical and temporal range, let's give it a go. Here is a webpage giving the taxonomy of archeocetans - the suborder of whale ancestors which are only found in the fossil records. Does the accumulation of new species within Archaeocetus follow randman's collector's curve. A quick analysis indicates that it is not a close fit and would be useless to make any guesstimate of what proportion of whale fossils have been found.I invite randman to show us how real data such as the linked taxonomy suports his assertions and/or provide alternative data and analysis which supports his assertions.

wi:

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His assertion of 90% completeness seems somehow to be based on the concept of a generalised collector's curve and a statement that all extant cetacean families are present in the fossil record.

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Let me add that I am still looking for confirmation of "all extant cetacean families are present in the fossil record" statement. I have not been able to locate that assertion elsewhere; while it is not esp. germane to the debate, I am curious about the source.

Perhaps randman is extrapolating from this link which he has referred to previously and includes the statement:

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A number of modern-day families of both toothed and baleen whales are known to have evolved by the late Miocene.

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no, i suspect not. evenm in the case of "living fossils" there is bound to be some genetic drift (at the very least). i would be amazed to find modern species dating back more thant a few million years.

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אָרַח

yeah, ok, guess i'm wrong on that one.my point was that saying the fossil record is totally devoid of anything that looks modern is also wrong.

What I am going to do is go back and try to force some statements to be backed up so this discussion, based on my original thread topic, can be confined to substantive debate of factual data on the fossil evidence for or against land mammal to whale transition.Therefore I am starting back from page 1 of this thread.This is the thread title. Imo, the topic appears to be fossils not all the other areas of evidence for or against you cite. Let's focus on your conclusion., Can you back that up without resorting to citing other fields of evidence? In other words, why would fossil evidence not be necessary or primary? What about the fossil evidence, hard physical data, is so meaningless?Your next point in the sentence reiterates your view. But what I want to know is how you can consider the few numbers of potential candidates are sufficient to support ToE. In other words, the claim implies that all we need are a few fossils, or in the quote above, none, to be evidence for ToE.But where is the study and analysis to support that claim? I have never seen you guys offer anything in that regard.Let's forget the issue of whether Pakicetus, whom I consider to be decidedly a non-whale, is a transitional. Can you show why we should not have found the transitionals?We see thousands of transionals for the aquatic serpent-like Baisolaurus, and thousands of genuine whale fossils, but we don't see thousands from the thousands of transitionals that should have occured.Where are the creatures in the fossil record?If you are arguing rarity, can you define rarity in this context and offer comparitive studies of mammals similar to the theoritical forms that show fossil rarity and why we should not see them?Please remember the thread is suppossed to be about fossils.

Is that a personal opinion, or do you have some scientific reasons for not seeing how quantify this?This is an early claim of your's on the thread. Let's make sure we resolve this issue before going on to other stuff.

We have a theortical time-frame the transition occurred. We can quantify the differences between the nearest land mammal and current whales, and we can thus begin there. Within that time-frame, you are correct that estimating rates year to year would be impossible, but we can theorize that a certain number of changes had to occur over a specific time-frame, which is the claim of ToE, and then test to see if is possible or likely based on observations of mutations in mammals and the degrees of change produced per set of mutations.

I offered a way to estimate this number, but think it should probably be done at the family level, not the species level. We can quantify differences in anatomy between the 2 whale suborders, and then the whale families, and compare that to the number of similarities, and create a percentage.We can do that with similarly related species and thier families, noting the ranges as well between any species that can interbreed, such as sometimes happens across whale genera.Then, we do the same between whales and their nearest land mammal relatives, say hippos or something like that. That should produce a range whereby we can develop estimates of how many transitional forms would need to have occurred by positing how many changes would typically occur that form into a new family, and we can also estimated auxilliary branches.This can be done, and imo, should be done before evolutionists claim the fossil evidence fits into ToE. Evolutionists make this claims, unsupported and then dismiss critics who say there should be more transitionals in the fossil record.Evos should not make claims as valid science unless they have done the work to substantiate the claim, and to date, I have not seen it.In my own life, the lack of transitional fossils is the primary reason I don't accept the ToE anymore. Again, I think you are wrong. We can do comparitive studies and assess based on scientific analysis a good range of what we should expect to see.

An "event" implies to me something which occurs in a localized place and time. No. The fallacy in your thinking is assuming the population does not branch and thus create multiple lineages.