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Author Topic:   Land Mammal to Whale transition: fossils Part II
Admin
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From: EvC Forum
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Message 241 of 288 (233725)
08-16-2005 3:02 PM
Reply to: Message 240 by randman
08-16-2005 2:28 PM


Re: basilosaurus numbers
To everyone,

This is from Randman:

Ned and others, I am not abandoning the thread, but I've got to work as well.

It is a good idea to let people know if the pattern of your replies will be different for a while, but please everyone, keep in mind that there is no time requirement on replies, though you should probably let people know if you'll be posting less often than once a week or intermittently. If you post all day, people will become accustomed to instant responses. If you post from the other side of the world, people will become accustomed to posting at different times from you. If you post once a week, people will become accustomed to that.

It is only when you break your pattern and begin posting, say, once week after participating every day that people begin to assume you've left the debate. When you have to be away for a while then it's not a bad idea to let people know, as Randman does here.

But, there is no time limit. Don't play at EvC Forum when you should be working!


--Percy
EvC Forum Director

This message is a reply to:
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Replies to this message:
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Wounded King
Member (Idle past 2260 days)
Posts: 4149
From: Edinburgh, Scotland
Joined: 04-09-2003


Message 242 of 288 (233816)
08-16-2005 6:45 PM
Reply to: Message 241 by Admin
08-16-2005 3:02 PM


Re: basilosaurus numbers
Don't play at EvC Forum when you should be working!

Now you tell me!!!! Oops, forgot multiple exclamation marks were sign of mental problem, what a give away.

TTFN,

WK

This message has been edited by Wounded King, 08-16-2005 06:46 PM

This message has been edited by Wounded King, 08-16-2005 06:47 PM


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NosyNed
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Posts: 8842
From: Canada
Joined: 04-04-2003


Message 243 of 288 (233860)
08-16-2005 9:14 PM
Reply to: Message 240 by randman
08-16-2005 2:28 PM


Units of Measure
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.

Thanks for the note regarding time.

The numbers we are discussing here are NOT species they are individuals (that's twice).

I'd agree that 1,000 individuals is about the bottom of the range I would be comfortable using while 10,000 is, perhaps, the upper end.

I too would like someone who knows more to comment.


This message is a reply to:
 Message 240 by randman, posted 08-16-2005 2:28 PM randman has responded

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randman 
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Posts: 6367
Joined: 05-26-2005


Message 244 of 288 (233917)
08-17-2005 12:48 AM
Reply to: Message 243 by NosyNed
08-16-2005 9:14 PM


Re: Units of Measure
Ned, still have no time to respond in-depth, but I obviously meant individuals, both times. I recognize that we are talking about individual members. Just a typo, but unfortunately, I'll have to get to all this later tomorrow evenining probably, maybe late.
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ringo
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Posts: 16637
From: frozen wasteland
Joined: 03-23-2005
Member Rating: 2.9


Message 245 of 288 (233925)
08-17-2005 3:16 AM
Reply to: Message 244 by randman
08-17-2005 12:48 AM


I've been thinking about the numbers....
randman,

I don't know if I follow your calculations completely, but it seems to me that you are claiming that there "should" be an average of 5 or so fossils found for each of the whale-ancestor transitionals. It also seems to me that you base your calculations somewhat on the "thousands" of Basilosaurus fossils which have been found.

But I think you're looking at it backwards. The number of Basilosaurus fossils seems to be an anomaly rather than the norm. For some reason, a large number of Basilosauri were preserved and/or a large number of Basilosaurus fossils have been found.

But that large number would tend to skew the average upward - i.e. the average "5 or so" fossils which we "should" see for each transitional would actually be much lower if the anomalous Basilosaurus data was excluded.

In fact, the average number of fossils that we "should" find - according to your own calculations - would be close to zero.


People who think they have all the answers usually don't understand the questions.
This message is a reply to:
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NosyNed
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Posts: 8842
From: Canada
Joined: 04-04-2003


Message 246 of 288 (234117)
08-17-2005 1:16 PM
Reply to: Message 245 by ringo
08-17-2005 3:16 AM


In order to "correct" such calcualtions...
It doesn't help to simply make statements about what you think the answer should be or that you think Basilosaurus is an "anomaly".

You have to back up to the input assumptions, give specific reasons why you would use different inputs and redo the calculations, correcting if need be.

You haven't done that here so this post isn't very helpful.

The Basilosaurus may very well not be representative enough but it is one of the inputs we have available to us right now.


This message is a reply to:
 Message 245 by ringo, posted 08-17-2005 3:16 AM ringo has responded

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ringo
Member
Posts: 16637
From: frozen wasteland
Joined: 03-23-2005
Member Rating: 2.9


Message 247 of 288 (234123)
08-17-2005 1:29 PM
Reply to: Message 246 by NosyNed
08-17-2005 1:16 PM


Re: In order to "correct" such calcualtions...
NosyNed writes:

It doesn't help to simply make statements about what you think the answer should be or that you think Basilosaurus is an "anomaly".

Yes, I should have been more clear in saying that Basilosaurus may be an anomaly.

My point is that if Basilosaurus is anomalous, then randman's calculations would be skewed upward - i.e. he would expect more fossils of whale transitionals.

Since randman has given Basilosaurus as his main quantitative example, I think it is quite relevant to question whether that data point is valid.


People who think they have all the answers usually don't understand the questions.
This message is a reply to:
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randman 
Suspended Member (Idle past 3065 days)
Posts: 6367
Joined: 05-26-2005


Message 248 of 288 (234234)
08-17-2005 6:55 PM
Reply to: Message 247 by ringo
08-17-2005 1:29 PM


Re: In order to "correct" such calcualtions...
To all, I've been very busy and need to do some research into whether there are actual estimates of polution size, what habitats were, etc,...and so while I've made a few comments on the EVC forum in the past day or so, I could do those with not much time and no research.

These numbers are interesing (and seem to work in my favor :cool:), but can be narrowed down I suspect. Estimates of population size and habitats should help.


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NosyNed
Member
Posts: 8842
From: Canada
Joined: 04-04-2003


Message 249 of 288 (234244)
08-17-2005 7:13 PM
Reply to: Message 247 by ringo
08-17-2005 1:29 PM


Re: In order to "correct" such calcualtions...
I picked the example since he had talked about it a lot and he was suggesting that there were such a large number of fossils of it.

We don't have enough hard information to get more than ballpark estimates but what we do have suggests that randman's idea that a large fraction of a population will fossilize was wrong by a factor of from 100 to, perhaps, 10,000's.


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NosyNed
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Posts: 8842
From: Canada
Joined: 04-04-2003


Message 250 of 288 (234249)
08-17-2005 7:19 PM
Reply to: Message 248 by randman
08-17-2005 6:55 PM


working in your favour
These numbers are interesing (and seem to work in my favor ), but can be narrowed down I suspect. Estimates of population size and habitats should help.

They do not work in your favour at all. As I recall the only number you gave for fossilization percentage was 90%.

The numbers we have suggest that is 100 times too high. It may be more like 100,000 or a million times too high.

Your idea that fossilization is not rare is contrary to what these ballpark estimates give us.

Now we find that the ballpark estimates are too rough to figure out whether we should expect total absence of some transitional species or that we should expect to find a handfull of them.

Your initial idea of what was going on are NOT supported by this.

However, I think we are now, as many have indicated in an area where there is inadequate information to be precise enough to come to a conclusion. We have probably also, finally, run out of things to do with this.


This message is a reply to:
 Message 248 by randman, posted 08-17-2005 6:55 PM randman has responded

Replies to this message:
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randman 
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Posts: 6367
Joined: 05-26-2005


Message 251 of 288 (234269)
08-17-2005 9:15 PM
Reply to: Message 250 by NosyNed
08-17-2005 7:19 PM


Re: working in your favour
You misread my high estimates. I never referred to most members of a species fossilizing, but that we see a high number of whale families and genera fossilized and in large numbers.

Based on my numbers here, it looks like we should expect fossils of every major transition. Remember that one fossil makes that 100% for that species.

Also, we have not run out of ways to resolve this at all since now we are engaging in real estimates. First, we can look up theoritical habitats, which I will do if no one else does, and secondly, come up with estimates of population within species of mammals occupying those habitats, and narrow down the numbers for a clearer picture, of which I am confident will support my case even more.

So give this some time for me or someone else to look up these specifics.

This message has been edited by randman, 08-17-2005 09:17 PM


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RAZD
Member
Posts: 19871
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 5.3


Message 252 of 288 (234279)
08-17-2005 10:06 PM
Reply to: Message 251 by randman
08-17-2005 9:15 PM


misconceptions abound.
Based on my numbers here, it looks like we should expect fossils of every major transition. Remember that one fossil makes that 100% for that species.

You expect a single organism to be an intermediate transition between two species?


we are limited in our ability to understand
by our ability to understand

RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}


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MangyTiger
Member (Idle past 4519 days)
Posts: 989
From: Leicester, UK
Joined: 07-30-2004


Message 253 of 288 (234280)
08-17-2005 10:06 PM
Reply to: Message 187 by randman
08-15-2005 1:36 AM


100,000,000 species?
Biologists estimate that there are around 1,000,000 living species of animals. Because invertebrate life appeared on earth more than 500 million years ago, paleontologists estimate that extinct species have an aggregate of at least 100 times that number.

I haven't had enough time to get to this until now and the thread has moved on past this, but since I said I'd reply...

There are around 1,000,000 living species of animal. The 100 multiplier used to get the number of extinct species is (I think) just got from the average life span of a species - around 4 to 5 million years - seen in the fossil record and the time since animals appeared.


Oops! Wrong Planet
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NosyNed
Member
Posts: 8842
From: Canada
Joined: 04-04-2003


Message 254 of 288 (234281)
08-17-2005 10:08 PM
Reply to: Message 251 by randman
08-17-2005 9:15 PM


Something not understood.
I don't understand :

You misread my high estimates. I never referred to most members of a species fossilizing, but that we see a high number of whale families and genera fossilized and in large numbers.

Could you explain?

Based on my numbers here, it looks like we should expect fossils of every major transition. Remember that one fossil makes that 100% for that species.

Maybe. We may well have all of the major transitions in the fossils we have. Any way to tell?


This message is a reply to:
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RAZD
Member
Posts: 19871
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 5.3


Message 255 of 288 (234285)
08-17-2005 10:13 PM
Reply to: Message 253 by MangyTiger
08-17-2005 10:06 PM


Re: 100,000,000 species?
Then, if we could ballpark an approximate average population size for each of those species, multiply the two together and divide the total number of known fossils by that product we would have the beginning of a idea of the rate of (found) fossils.

Just for fun let's assume that the population size is the same order of magnetude as the number of fossils found to date. That makes the rate of fossilization 1 in 100,000,000.

(Ignoring the bias of fossils towards species that lived in the specific places where we are finding fossils ...)


we are limited in our ability to understand
by our ability to understand

RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}


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