Continuing the discussion from Convergent Loss or Common Descent?:
@scd, I think this is a good starting question to focus on. You are open to either possibility, so let’s try looking at that first. Maybe you will more clearly see how scientists make sense of evidence. That will give a better foundation for the conversation about evolution, when we get back to it.
So, what do you think about this article on Varves by @Joel_Duff?
scd, a couple of quick reactions. First, some observations can fit either a young or an old earth but not really distinguish between the two scenarios so those observations don’t provide particularly useful information if our intent is to find evidence that points us in strongly in the direction of one view of earth’s history or another. As you say, recent population growth fits a young-earth timeline but it doesn’t exclude a old-earth timeline. If a young-earth is supported by a large body of evidence then one could say, ah, and this observation of population growth is also explained by population growth. However, it would be a weak evidence to use as a starting point for showing the earth must be young.
Second, I don’t know anyone that accepts the aDNA from the Miocene sample anymore. I know the aDNA literature quite well and there is considerable skepticism of this study. The very result they report provides the evidence that one needs to be skeptical. Notice that what they report is the sequencing of a fossil which yielded a DNA sequence 100% identical to a living species. Now, you might think that if the world is young that this isn’t a surprise but even if this sample were 4500 years old and really was the identical species I would not expect a DNA sequence to be identical from an ancient sample even if the original DNA in that plant really were identical. Why? because DNA undergoes damage (even in 4000 years) to certain basepairs resulting in fairly common types of individual changes to the sequence. If the sample were ancient I would expect differences just due to damage not to the original sequence being different. The very fact they got a 100% identical sequence to a living plant is very strong evidence that they sample they sequenced was not ancient (in a young or old earth scenario). Regardless, I don’t have a problem with the possibility that DNA could preserved for millions of years. Under very specific conditions I am sure that a few individual bair pairs can survive and with better technology we are pushing back the time quite a bit over what was possible 10 years ago. What is clear is that DNA can survive quite readily under many conditions (even if only 0.0001% of an organisms DNA is preserved that would be enough to sequence its genome) for 4000 years and so in a young-earth model I would expect that we should be able to obtain DNA sequences from virtually all extinct organisms.
thanks for the comment (again: english isnt my native so in general i dont understand some words here and there). the problem is that all the evidence we do have so far dont predict that DNA will survive so long time. about the 100% identity: again- how many difference we can predict if this sequence was say about 10000 years old?
That is not correct. As we have shown in other threads, the genetic data is totally in conflict with the YEC account. Selectively presenting evidence is not going to convince people.
That seems like definitive evidence that it is contamination. DNA from fossil that 100% identical to living species is in strong conflict with the YEC model.
This gets to a key point @scd. It is not enough to poke holes with random observations. You have to build a positive and coherent alternative. From our point of view, this looks exactly like contamination. From the YEC point of view, what is it? Contamination works too, but that would take away their argument. However, if this isn’t contamination, it demonstrates that all their hyper-evolution models are wrong. So the situation regarding this DNA is either:
So, an honest account would either choose #1, or choose #2 while acknowledging both #2.1 and #2.2. Instead, the sources you are reading just ignore #1 and #2.2, and focus on #2.1, as if it is definitive evidence against an old earth. That is not honest. It convinces no one who cares about evidence and honesty.
They fall into the trap because they are much more concerned with disproving evolution than making sense of the world. That is why we do not trust it.
Do you understand the problem with this argument?
As a critical point, you also entirely ignored my question. That is another classic red flag,
as i said: we have also evidence for an old earth, so this sould be one of them. as for the DNA. if this DNA is real how it will be a problem for a young earth? remember again: i dont realy care about the age of the earth.
I know. That is why this is important. It is your opportunity to understand how scientists process information. Without that, nothing will make sense in an area that does matter to you.
It is real DNA, and it looks like contamination from the present day. (if the descriptions here are correct, that is)
If it were really ancient DNA that was 100% identical to modern DNA, this is against the YEC model. The YEC model requires very high mutation rates (about 100x more than we observe) to produce the variation in DNA we see around us. For ancient DNA to be 100% identical, it would have to be much lower than the observed rates. It would be very difficult to make sense of in a YEC framework.
Of course, the most likely answer is that this is just contamination. No surprise here. Happens all the time. It is just shoddy science it was published.
The key point is that it is not enough to show a problem in another person’s model with a random data point. We have show a pattern of facts, and we have to make more sense of it in our preferred model.
understand. thanks. but how do we know that its not a conserve region?
@scd,
1] The existing dominance of marsupials in Australia cannot fit the YEC scenario.
2] The YEC scenario is also incompatible with the 100,000 years of arctic ice cores OR the Japanese data set for 60,000 years.
There’s really no point in discussing YEC logic for your sake, if you are not a YEC proponent.
@anon46279830 has a position of Serial Special Creation for his Old Earth Scenario. Are you familiar with his views on this?
i guess that anything is possible.
So… @scd, this tells me that you don’t even accept @anon46279830’s explanation for the nested hierarchies we see.
And yet Revealed comes the closest of all the Creationist positions to corresponding with the fossil data (and geology) as God has provided us.
What is your position that you would HOPE would be as good as Revealed’s?
i actually said that anything is possible.
Well, let me know when you make up your mind on what is probable.
I’m not going to spend any more time on an “anything is possible” conversation.