|
Register | Sign In |
|
QuickSearch
EvC Forum active members: 64 (9164 total) |
| |
ChatGPT | |
Total: 916,786 Year: 4,043/9,624 Month: 914/974 Week: 241/286 Day: 2/46 Hour: 0/2 |
Thread ▼ Details |
|
Thread Info
|
|
|
Author | Topic: Bison at La Brea Tar Pits | |||||||||||||||||||||||
Christian Member (Idle past 6282 days) Posts: 157 Joined: |
Yes, I'm still around. I'm even a moderator! Though I don't have time to do much moderating.
|
|||||||||||||||||||||||
jar Member (Idle past 420 days) Posts: 34026 From: Texas!! Joined: |
one that is a major reason that the Flood Scenario has been completely abandoned for so many centuries.
Assume for a second that you are correct when you say
3. Their scenario doesn't seem very likely. What seems more likely is that there was some sudden event which killed all those animals, and there were bison ranging from 2-4 months which had been born that year, bison ranging from 14-16 months which had been born last year, and bison ranging from 26-30 months which had been born two years previously. and that sudden event was the Biblical Flood. If that is true, then certain other things also must be true and the evidence for them must be equally apparent.
If you use the contents of the La Brea Tar Pits as the dating incident for the Flood, then the Flood happened at that particular era. If we find a record somewhere in the world covering that era that shows no sign of flooding, then the sudden event that you propose as the cause for the Bison at La Brea was not universal in extent. Unfortunately for Flood supporters, that is exactly what is found. There are many even more clear examples of catastrophic flooding found all over the world. But they are not all contemporary. Instead, what is found are examples of local or regional floods, some of immense proportions, but also not all happening at the same time. Aslan is not a Tame Lion
|
|||||||||||||||||||||||
Christian Member (Idle past 6282 days) Posts: 157 Joined: |
Modulous writes:
Thanks Modulous, I would like to see what those other factors are. Assuming there are no other factors involved would seem to suggest Christian was right - however as you say, there are likely other factors not discussed in the brief text presented.
|
|||||||||||||||||||||||
Modulous Member Posts: 7801 From: Manchester, UK Joined: |
Thanks Modulous, I would like to see what those other factors are. I covered a couple of possibilities at the bottom of my Message 8.
|
|||||||||||||||||||||||
Christian Member (Idle past 6282 days) Posts: 157 Joined: |
jar writes:
Then let's not assume it's true. Lets assume the migration scenario is true and see how well that fits the evidence. I'd rather take things one step at a time. I want to know if I am right that their scenario is unsatisfactory. That's all.
If that is true, then certain other things also must be true and the evidence for them must be equally apparent. jar writes:
no, but He is good.
Aslan is not a Tame Lion
|
|||||||||||||||||||||||
Christian Member (Idle past 6282 days) Posts: 157 Joined: |
Modulous writes:
Oh yeah, I almost forgot to reply to that one.
I covered a couple of possibilities at the bottom of my Message 8. Modulous writes: Perhaps the calves we see in the pits were weaned? We'd need more information to be sure (the nature of the teeth wearing for example). yes, nature of teeth wearing would help. But I have a book on Bison that says the calves nurse for about 8-12 months. So If the ancient bison nursed for that long too, it wouldn't work because most of the bison were between 2-4 months. I have a picture of a graph which illustrates that, but I don't have time to get the picture up for you now. It will have to wait.
Modulous writes:
I'm not sure how this would explain anything. Alternatively, as Lithoid has said, it could be that we are getting the information worded within error bars (that is, the ages of the calves found are 3 months plus or minus one month).
|
|||||||||||||||||||||||
NosyNed Member Posts: 9003 From: Canada Joined: |
I'm only pointing out that their scenario doesn't work very well, and that their info is misleading and false. I agree that with what information we have it doesn't work out. I suggest that characterizing it as "misleading and false" is a bit premature. We don't know enough to know what they started with before creating a very, very short summary with simplifications for a museum display. It does appear that they didn't do that well enough but we don't know yet.
It was yours. And I don't think bison migrating patterns are that precise. They seem to vary from year to year.Whatever the case, the conditions would have to be almost exactly the same every year for many thousands of years. Not exactly the same. Only to within the accuracy of the age measurements. Not exactly the same only enough that the great preponderance of the captured calves fit the ranges. The captured calves are given as varying over a 4 month range of ages. That is pretty wide. We don't know if there was a variation in the range of captured age with date of capture either. The museum sign all by itself doesn't hang together very well. We don't know enough to determine what is wrong. You are jumping to conclusions. If calves were born at the same time as modern bison (April to August?) then calves under 5 months old (only, and year increments above that) do indicate that they were there during late spring. It also suggests that they must have been there during other times later in the year too but the sign is messed up enough to be unclear.
What "information" am I adding that's not there? I was mistaken on this. Sorry.
I hope you're not accusing ME of intelectual dishonesty. No I am not. Only if you attempt to use confusion of a simplified museum sign to hint that the flood is a reasonable explanation. You haven't been clear if you have or not. You did mention a single event, that is clearly out of the question. I think we both agree that the topic here is the quality of information presented at the museum and NOT any other explanation for the pattern found. We'll leave that alone.
But it does say No bison have yet been recovered that are of intermediate ages- 5 to 13 months old or 17 to 25 months old. Yes, but that doesn't tell us how those ranges are determined. Are the found fossils aged to within +- 1 week and measured to be between 0 and 4.5 months or +- 2 months and measured to be about 2 months old? Measurements based on wear would indicate something like the former (but not as tight as one week I wouldn't think), measurements based on development of the teeth or skeleton might indicate something more like the latter.
|
|||||||||||||||||||||||
Modulous Member Posts: 7801 From: Manchester, UK Joined: |
yes, nature of teeth wearing would help. But I have a book on Bison that says the calves nurse for about 8-12 months. Well it seems we have either a contradiction of sources (the ones I looked at suggested differently with 7 months as a maximum, and some reason to believe it might be shorter), or different definitions of nursing and weaning. As I said, we'd need more information on the whole thing. It could be that the age span of bison in the area included younger bison, but that the older bison are particularly vulnerable (eg they have more independence, but not the sense to fully keep out danger). This might the age, for example, where the weaning process begins - so the young 'ens start exploring for food. Unfortunately, without decent levels of information, I'm unwilling to to provide any solid conclusions.
I'm not sure how [error bars] would explain anything. I think the point is that if they age a bison at 4 months old, the error on it is 1 month either way, so the bison could be 5 months old or three months old. At the other end they might age it at 2 months, but the error bars give us between 1 and 3 months. At this time, they've not found anything that dates to 5 months (plus or minus a month). As such the potential age of the bison is between 1 to 5 month. That accounts for staying in the area for a while and a gap between calves. It might be that they have averaged the tested age as being 3 months, and applied the error bars to that for 2-4 months. Once again, we'd need to know the primary information in order to discern how the museum has simplified it for the public.
|
|||||||||||||||||||||||
MangyTiger Member (Idle past 6380 days) Posts: 989 From: Leicester, UK Joined: |
I suddenly realised as I was reading the most recent posts that we're missing a trick here.
As you explain in the Opening Post, you think the information on the sign doesn't add up. There are repeated comments from others in the thread to the effect of 'we don't know what (published research etc.) they based the information on the sign on'. Surely the obvious solution is for you to contact the Museum describing your queries/concerns and ask them if they can provide further information to substantiate the summary on the sign. Assuming you get a reply you can then share it with us (if you do it by e-mail then you can just cut'n'paste it into here to save having to type it all in ). I wish I didn't know now what I didn't know then
|
|||||||||||||||||||||||
Omnivorous Member Posts: 3988 From: Adirondackia Joined: Member Rating: 6.9 |
I see no problem with the sign. Perhaps someone could explain the difficulty more clearly? To merit charges of misleading and false, I would have expected the problem to leap off the page.
The museum's web site tells us that the climate in the area was cooler and more humid (more like San Francisco at present), and that the warmer months were the most dangerous because the asphalt was softer and more likely to be concealed by leaves and other debris. In particular, I don't understand the notion that the bison would have had to migrate/calve at almost exactly the same day each year for thousands of years, given that the age ranges are months. Since the key data were the relative annual age clusters, what difference does it make which day they were calved? Even if the climate, migratory schedule, or birthing season varied considerably over the millennia, the variance between one year and the next would likely be low. According to the museum, just 10 large mammals being captured every ten years would account for the total mammal assemblage found: how many were bison? How long did bison capture continue? I bet the researchers at La Brea are thrilled each time a school child e-mails them with that kind of question, though I guess it's easier for adults to call them liars. Perhaps someone can help me out here. I don't see anything dishonest, misleading, contradictory, or inadequate about the sign. It presents a bite-sized nugget of scientific hypothesis and is intended to make one ask questions and want to learn more. Christian's OP and subsequent posts are quite ad hoc, but that is a function of intellectual bias, or incompetence, not dishonesty.
|
|||||||||||||||||||||||
NosyNed Member Posts: 9003 From: Canada Joined: |
From here: http://www.nhm.org/cats/C24/bison.htm
quote: That looks about right for the kind of thing one might see in a museum. So here is what I understand the problem to be:1) Calves born at the same time of year as modern bison means born from april through july or even august with "most" born in the first half of May. The oldest would be born then 2 months before the end of spring. Therefore the wording "were present at Rancho La Brea every year during late spring" can not be right if they are from 2 to 4 months old. It would be correct if they arrived in late spring. However, if it is the oldest that arrive there at two months old in "late spring" then there should be ones found all the way down to new born but it says they aren't. The second problem is it says there were there "a few months" of the year. But the age ranges are only 2 months and some people don't consider a "couple" of months to be "a few". So given the quote from the web site we have a problem making it precisely correct. Shall I try to write something which is correct? If the bison migrated through they can't take longer than 2 months since that is the full range of calf fossils found -- this is not a "few months" so it should be worked a "couple of months". Assuming that a LOT of calves are captured in the tar so that ALL actual age ranges are represented: If they are born the same time as modern bison then they can't arrive until 2 months after NO more calves are born and captured. But that means that the oldest would be more than 4 months (since modern bison are claimed to calve over a period that is longer than 2 months) so the two assumptions cannot be true. Either we are getting a non-representative sample or the bison calved over a shorter period of time than the one we assume is good for modern bison. The "facts" are supposed to be:1) born in the same pattern as modern bison which are taken as being over about a 4 month period from late April. 2) None found outside of the 2 month to 4 month (+ 1 year increments) age ranges. 3) arrive in "late spring" 4) stay a "few months" I can't construct a sign which makes sense given the above. Can you? Maybe I should email this? I'll wait for Christian in case he wants to do it or word it.So I can't make a sign up that presents the same "facts"
|
|||||||||||||||||||||||
jar Member (Idle past 420 days) Posts: 34026 From: Texas!! Joined: |
Some other questions I think need answering. One day when she (Christian) was in chat we went over a few of them.
Is it possible that there are reasons other than migration that might explain what is seen?
Aslan is not a Tame Lion
|
|||||||||||||||||||||||
Omnivorous Member Posts: 3988 From: Adirondackia Joined: Member Rating: 6.9 |
Thanks, Nosy. I see the "problem" better now.
It's a tempest in a tarpit. Bison, which are migratory animals, were present at La Brea for at least two months of the year, given the ages of the youngest calves captured: possibly, given the age clumping range, they could have been there four months each year. Given the calving habits of modern bison--and the seasonal nature of the tarpit hazard--we can conclude the bison were present at La Brea in late spring when the hazard began to increase due to temperature. The bison left the area before any new calves had aged more than four months. So if they arrived in April with some immediate calving ocurring, with most calving in May, and with the hazard increasing in June and peaking in July, just when the bison might seeker greener, cooler pastures (just as an example motivator--the captured large mammals also attracted predators the bison might want to avoid)...they would be there a few months, calves 2-4 months could be captured, and none older. As to finding newborns in the tarpit, IIRC, few large mammals have precocial young, and as I specifically recall, bison herds organize with cows and calves to the center, bulls protectively at the perimeter; the newborns who felt footloose were unlikely to survive long in the land of the direwolf and short-face bear. Doesn't that work? BTW, do we actually have migrating herds of bison these days?
|
|||||||||||||||||||||||
RAZD Member (Idle past 1431 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Hello Christian,
Let's see if I can help.
quote: Starting with a null hypothesis, there are several ways to explain this:
Regarding (2), while mating seasons have been observed to cause behavior in adults that could be deemed 'less cautious' and make them prone to being caught in the tar, this can be pretty well ruled out for newborns and yearlings, as it has not been observed in modern bison nor in other species. Likewise regarding (3), this can be ruled out by the presence of other non-migratory animal remains that show a year-round pattern (I am assuming that this has been {considered\done\evaluated} because they talk about bison and not all the species found in the tar pits -- they single out a migratory species). Regarding (4), while more data is always nice, there comes a point where the pattern emerges that further data only reinforces rather than alters the conclusions. Let's take your information provided:
Modern bison calves are born mostly in may but can be born any time from mid April through July or August. There were no newborn calves, no one month old calves. What you should develop is a distribution curve of births against day of the year, this would show that, say, 90% of the births were in May, with some before and slightly more after. The next thing to do then is to look at how a sampling of that population during a one month period, a two month period and a three month period at different times of the year would look, and then compare that with the tar pit results for a best match. More data could provide a sample or two in the "off" months, but the numbers of other samples in the "on" months would still means it fits the pattern, yes? This rather leaves us with (1) - which also matches observed patterns of behavior in {modern} bison - as the most likely scenario, unless you can think of other options.
... Also they would've had to go through the area during the same few days every year for 30,000 years. ... I think if you play with the data for your births versus time of year curve (with a one month period for most births) and look for ways to get consistent 2 month groupings of ages that they could have stayed about a month in the area. And we are talking a migratory species too, right?
This statement: quote:cannot be true unless all the bison were born on or very near the same day, every year for the 30,000 years represented by the tar pits. No, it just means that there are ages that are missing from the data, as could not occur in a non-migratory species. A non-migratory species would have young getting trapped all year round (I'm assuming this is a fact re (3) above), and thus would be all ages. We know there are months when bison do not reproduce, and again, by matching the pattern of births vs time of year against age clusters shows that the bison were only there part of the year.
This statement: quote:... Modern bison calves are born mostly in may ... If all the calves were born in May, they would've had to go through Rancho La Brea in July, August, or September (mid summer to early fall) You could have a point here - change late spring to summer - but this does not invalidate the conclusion of periodic visits, just the timing of them. We are still left with a migratory species leaving clustered ages of entrapments.
3. Their scenario doesn't seem very likely. What seems more likely is that there was some sudden event ... I'm sorry, but you lost me there. You've just been arguing that this couldn't have occurred as described because it would have required a narrow window in time each year, and then you say a more likely theory is an even narrower time window? Don't all the objections you raised above apply equally to this theory? If so, then it isn't any more likely, is it? What we need is a test that would differentiate results from the two theories to see which is more likely.
...some sudden event which killed all those animals, and there were bison ranging from 2-4 months which had been born that year, bison ranging from 14-16 months which had been born last year, and bison ranging from 26-30 months which had been born two years previously. The problem here is that this does not account for the data from non-migratory species that would have victims of all ages (see above re (3)). Given that this data would invalidate your theory, and given that it was likely a part of forming the conclusions regarding the bison (as oppossed to other species), I can't "agree with (you) that a sudden event is more likely" -- sorry. k? ps -- how goes the time troubles? we are limited in our ability to understand by our ability to understand RebelAAmerican.Zen[Deist
... to learn ... to think ... to live ... to laugh ... to share.
|
|||||||||||||||||||||||
DominionSeraph Member (Idle past 4781 days) Posts: 365 From: on High Joined: |
I think the sign is worded fine. It ain't supposed to be a math problem, so if the uncertainty included in the wording is screwing up your attempts to solve for X, get over it.
This message has been edited by DominionSeraph, 04-18-2006 01:24 AM
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024