Land Mammal to Whale transition: fossils Part II

the 10 or so Myrs is about right as randman notes. The archecetacean were fully aquatic by that time.

Basilosaurus was, it seems, around for about 5 million years. Have you attempted to figure out how many individuals of that species may have lived in that time.This is a place where you might use numbers from extant whale species. Why don't you demonstrate an ability to make such an estimate (we aren't worried about precise accuracy just reasonableness of approach).

no, i don't think that would be reasonable. if only because there was never a human industry in basilosaurus blubber and bones.

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אָרַח

Ned, I am taking a day or so from this thread so as not to be unduly heated in debate, but I want to note something.Basiloraurus is considered to be part of a family, Basilosauridae. I am not sure if this is sort of a tacit estimate of the type I am looking for or not, but the concept of a form being represented by this species is interesting, and it appears the evo standard here is to classify this form as cetacean, but as a distinct family.I wonder if it should not be considered a separate suborder. Certainly, the 2 current suborders are far closer to each other than to Basilosauridae, and in fact, one wonders if there should not be suborders and families in between.Tomorrow, I will think about how to do an analysis as you suggest, of individual population levels. Imo, as you know, this is not my approach. My approach is to look statistical ranges for similarities and differences in forms, defined as either species or families of species and suborders. Estimating actual population counts is not something I see as necessary.The point is there are lots of Basiloraurus fossils and lots of fossils of the 2 current suborders, but few to none in between, and very few prior. Once again, I do think estimating ranges of differences is valid, and that there should be multiple forms between Basiloraurus and the current whale suborders, and many more multiple forms between land mammals and Basiloraurus.

There are estimates that the eastern pacific gray is back up to about historic figures (though some historic numbers may be low by a factor of 10).That beastie is about the size of a basilosaurus. It doesn't range over the whole ocean and this is only the eastern population so you are right we might get an underestimate if we used the 20,000 of them as an example.But, let's see how randman can do with these inputs.(btw I think a reasonable whale generation is 50 years)

This is a very, very simple calculation. About 2 minutes should cover it. It is directly useful in the discussions at hand.If you need a long time I will give it to you as a 2 day suspension. Whould that help?You have told us about the large number of Basiosauri fossils. Are you know saying that they are divided into separate groups and there aren't so many fossils of each type after all?Why don't we just stick with the larger grouping that has produced the, I think you called it, "HUGE" numbers of fossils? That is where you started.

ok, fair enough.

Nosey, you missed the point entirely. I am not saying there are separate groups, and really am not sure what evos claim. It seems sort of vague. Maybe this is a genera, but which evos place in a theoritical family since it is so unique and different.That was my point, and my suggestion is that it is so different that it seems to fit more as a separate suborder.In terms of calculations, maybe you see it as an easy thing, but estimating populations would need to be based on numbers prior to man, and I am not sure what that number is.Since you think it is so easy to know, maybe you can do the calculation?Also, do we estimate this as the same as one whale species, or more likely, as I suggest above, more along the lines of a suborder.I'd say it is more likely to be more similar in numbers to one of the whale suborders before man began to hunt whales.If you know that number, I'd venture a guess it's the same, except maybe less since Basiloraurus are so big. So I'd say more like a quarter of the numbers of one of the whale suborders.The more I think of it, I'd say probably even less than that because whales have been around a lot longer and had more time to become well-established.I am also unfamiliar with the proposed range of Basiloraurus. Is he an open sea or estuary type of creature?That question needs to be addressed first.This message has been edited by randman, 08-16-2005 02:04 AM

How about we use half of the population of one subspecies of extant whale?There are about 20,000 eastern grays now. That is estimated to be about the historic population.Let's use 10,000 as the world wide population average of all the Basilosauri species as compared to one group of a the grays (there was a western population of grays too but there are few left).Whale generations are a few decades long. I think we would be pretty close if we took 50 years. Ok with you?The basiosauri were around for about 5 million years as you have noted elsewhere I think. That is 100,000 generations.If the population averaged 10,000 individuals there were about 1 billion of them alive at one time or another. If we have found 1 MILLION fossils of them (which is about 3 orders of magnitude too high isn't it?) then the found fossils represent .1 % of them.Care to comment? I'm sorry to do complex things like multiple and divide but counting colored balls one at a time was too time consuming.ABE
As you can see the final answer give low fossil "hit" rates within a wide range of estimates for the inputs.PS If I use a modern whale suborder I'd be forced to use an average population that would be at LEAST 10,000 and 100,000 would be more like it so let's use the smaller grouping to not over estimate the numbers of individuals.This message has been edited by NosyNed, 08-16-2005 02:06 AM

That analysis is fine to illustrate a point. Btw, I was still working on an edit on the other post. I was trying to find out if studies had been done to suggest whether or not Basiloraurus was an estuary type creature or more open ocean. Maybe bone studies suggesting marine versus tidewater salt levels?But the .1% figure, or even less, is the percentage of individual members of species that fossilize and the fossils having been found, right?That's not the same as trying to figure out rates for species as a whole fossilizing and the fossils being discovered, but if it were, let's just say it was more like .0001%.We would then still most likely have every species or genera represented because out of every 10,000 individual members of a species, we would have one fossil for that species, and don't you think over thousands and millions of years, there are more than 10K members of species on average?This message has been edited by randman, 08-16-2005 02:13 AM

Let's make this more realistic. Let's up the population to 100,000, which I think is not a bad estimate for just guessing, and the multiply that times 100,000 as you suggest.That is 10,000,000,000 species that ever lived.You may be surprised but from the accounts of plenty of just regular people having and using these fossils, as lamp-posts and what-not, I think 100,000 fossils though not full forms is reasonable.So the ratio of species that ever lived to a fossil being discovered would be 10 million to one, right?So let's take a relatively small population of 1000 species with a life-span on average of 10 years, and they live for 2 million years. They are not as successful as most. So there would be 1000 species times 200,000 generations. That would leave 200 million species, right?Let's say they live a little longer, 20 years on average, and they only last 2 million years, that would be 100,000 generations times 1000 species and give us something like 100 million, correct?Let's say that they are not as likely to fossilize and be discovered so we cut that in half, and come up with 50 million.We should still then see 5 fossils, right?My point is we seem to find a lot of fossils for some, but often no fossils of the many species and/or genera/family that should be there. Based on these numbers, it's hard to imagine, except by plain bad luck, that a family or genera if not species would not be well-represented. Sure, we can discount some due to loss of the terrain they lived in, but we are not seeing hardly any.It doesn't add up.Don't you agree, at least based on your numbers and mine which give more leeway to the evo side of things.This message has been edited by randman, 08-16-2005 02:43 AMThis message has been edited by randman, 08-16-2005 02:47 AM

You are right. If Basilosaurus is representative (or less likely to give us fossils than the transitionals that came before) we should get from 1 to 10 specimens of each.However, Basilosaurus is useful to give us an estimate on one extreme. It shows that even in this case ( a larger, long lived population) your initial idea of how many fossils we should find are out by a factor of at least 1,000.Now we are after the number of fossils for the species involved in a narrow geographic region and for much less than 5 million years. With such small numbers of fossils expected (somewhere between 10 and less than 1) we run into statistical fluctuations which can easily remove any for a particular species. So we are in a range where missing a species is no longer so impossible at all. What do we expect now?It is time to look in more detail at the first 10 million years of archeoceti evolution then.I don't think that a population would be viable at less than 1,000 individuals and since we are looking at small populations that allow the rapid transition from land to aquatic in the time from about 53 Myr ago to 40 Myr ago then the population could not be as big as the 10,000 of Basiosaurus.I think, to be fair, we would have to drop the average generation length from that of the larger, later whales -- say 13 years to make the calculations easier. (I'm picking numbers here to help your case)We end up with a million generations. If we use 1,000 as the population we have 1 billion individuals and should expect to have a total of about 1,000 fossils. If we go up to the larger population we expect about 10,000 fossils.I don't know how many we have but I'm pretty sure we don't have 1,000 across this 13 Myr time frame. We are missing 100's of fossils.You are wrong and right: found fossils are rare (very rare) but we still don't have enough in the 13 Myr transition time.Does that mean they aren't there? The numbers aren't conclusive. Now if we are out by a factor of only 10 in any of the inputs we find ourselves with a number that does correspond to the number of fossils found.However, I can't think of a way of refining this to sort out which it is.You have been ranting over something that can't be driven to a very conclusive final answer. Fossils are very rare (based on all the numbers we have been able to cobble together. But there are hints that we should have more transtionals from the early eocene.I am more curious now about how many we do have. We have a handful of species from that time frame, no? We have more than one sample of some of them. We might have as many as 100 fossils (I'd be surprised if more). I'd be happier if we had 1,000; you'd be happier if we had 10.Where are we? Undecided.

You are doing something that is careless. Choosing to push the input in the direction of the results you want. Is this for Basilosaurus? That isn't out of line based on modern whales but from what I've read Basilosaurus might be less than wide open ocean going (of course we don't find fossils from the deep oceans so that might be wrong). However, we are finding fossils only where the oceans were over present day land. Using a larger population size is worse for your case so I shouldn't mind. It seems to big to me though. The old estimates for some of the open ocean whales (like the right and humpback) IIRC were about 20 or 30 or so 1,000 individuals; recent studies suggest that they may have been 10 times bigger which supports the 100, 000 population number but to be less supportive of my side let's stick with only 10's of 1,000's. I disagree. One to a few 1,000 fossils would be a very large number for this type of beastie. I'd be less surprised if we had just a few 100 world wide. Maybe someone can research this and give a more definitive answer. We are in disagreement by a factor of 100 here.I think the 100,000 generations is pretty fine. I don't think it can be low or high by more than a factor of 2.{qs}That is 10,000,000,000 species that ever lived.[/qs]Whatever the inputs this number is for numbers of individuals that have lived NOT species. That is the number of individual Basilosauri who lived.I think your estimate of the population is high by about 10 and the number of found fossils is high by about a factor of 100. This would make your odds about 100 million to one. If I am right about population and you are right about fossils the odds are 10,000 to one. If I am right about fossils and you are right about population then the odds are 1 billion to one. We need better estimates of those things.I think the idea that there should be 100's of millions of individuals over the time frames is about right. This applies however they are divided up into different species. This somes from the large number of generations primarily. It is hard to pick a reasonable population that doesn't produce a lot of individuals over 10,000,000,000 years.We are talking about the transition period. The populations will be smaller -- 1,000 we can use for now (it is good for my view ) but it is as small as I think we can use.Now we have odds over too wide range to settle this. We also have to be careful in a detailed way that Basilosaurus is representative of the transitional populations. Basilosaurus swam in seas that have since retreated. If, once they left the land for good, the transitionals were in the Indian ocean where it is today then we loose them all. Now we need to know where the seas were during the time from 53 Myr to about 40 Myr ago. (Clearly by 40 they were over places where we should be able to find fossils).Then we have to see if the transitionals were in places as combed for fossils as Basilosaurus. Pretty sure not since Louisiana (for example) is a lot more accessable than the pakistan. Even if all the various numbers are right and we should see 5 fossils (that could be 50 or less than 1) every 2 million years then we are now down to numbers where just plain bad luck can stop us from finding a species.At your 5 number we should have something like 25 or 30 separate fossils from the transition period. That is about how many we have within a factor of two I am guessing. I'll bet we have more than 10 and expect it is more like 20. Now we need to count those too. I'm too tired to dig deeper into it.As I said before. The numbers are not as overwhelmingly convincing as you were suggesting. In fact, they are starting to look more like what you were told in the first place. If we have many millions of individuals then we might start to hope to find a handfull of them fossilized. This is no longer a guarenteed sure thing. It is certainly enough to allow the other morphological and genetic evidence to guide us without worrying that we are missing something important.

For dancing? Sorry.It is a good question. I would guess that a creationist who believes God has a sense of humor could explain it.

Ned and others, I am not abandoning the thread, but I've got to work as well. I'll come back to this later. Edit to add that the 1000 species per generation probably is way too small, but we can do some research and get better numbers.This message has been edited by randman, 08-16-2005 02:35 PM