Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 79 (8908 total)
Current session began: 
Page Loaded: 05-26-2019 8:15 PM
28 online now:
AZPaul3, Coragyps, dwise1, JonF (4 members, 24 visitors)
Chatting now:  Chat room empty
Newest Member: WeloTemo
Post Volume:
Total: 852,094 Year: 7,130/19,786 Month: 1,671/1,581 Week: 50/443 Day: 50/34 Hour: 0/1


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   secularists do not want the truth
bluegenes
Member (Idle past 619 days)
Posts: 3119
From: U.K.
Joined: 01-24-2007


Message 73 of 85 (577347)
08-28-2010 8:06 AM
Reply to: Message 72 by Percy
08-28-2010 7:34 AM


More detailed research/ mtDNA mutation rate.
Percy writes:

If I'm wrong about this last part then all you need do is explain why Parsons estimate of mitochondrial mutation rates should be used in making the calculation for Mit-Eve. If a properly scientific approach says that Mit-Eve lived just 6000 years ago then I'm sure that's fine by everyone here.

To help you and Slevesque with this discussion, here's a paper which is about research from a much larger number of transmission events than the Parsons paper Sleve brought up.

It mentions the Parsons paper, and includes Parsons' results along with their own and those from two other surveys in a final average (in the "discussion" section).

I haven't got time to do it now, but a few years ago I worked out from this data that the youngest possible age for the mtDNA Eve would be about 15,000 years.

For various reasons, she could be a lot older than that.

More detailed research on human mtDNA mutation rate.


This message is a reply to:
 Message 72 by Percy, posted 08-28-2010 7:34 AM Percy has acknowledged this reply

  
bluegenes
Member (Idle past 619 days)
Posts: 3119
From: U.K.
Joined: 01-24-2007


Message 78 of 85 (577703)
08-30-2010 5:08 AM
Reply to: Message 77 by slevesque
08-29-2010 7:05 PM


Bring in more data, and calculate.
slevesque writes:

Because it is an actual real-time measurement of the rate. It's operational science. This reason should favor the pedigree based approach.

So, did you read the paper I linked to above? Message 73

Larger survey on mtDNA mutation rates with discussion including Parsons' data.

If you did, and that was the only data that you had to go on, you would conclude that the most recent time that all humans (not including neandertals) could have a common female ancestor is very unlikely to be less than 10,000 years ago, and therefore, with that as the only data, the earth is very unlikely to be less than 10,000 years old.

slevesque writes:

The phylogeny based approach really only gives us a prediction of what the Theory of Evolution says the rate should be. What happens when you go and actually measure what the rate is, and it comes out to be not at all what the theory predicted ? Should you still trust the phylogeny-based rate ??

There are problems with the actual rate of occurrence as a long term measurement. If all the mutations are neutral, then about half would drift out in the long term. If some are slightly disadvantageous, then those would be liable to negative selection in the long term.

Then there's the problem of hotspots, which means that mutations could reverse back and forth amongst other things. Then there's the problem that, on rare occasions, a woman might have a slightly advantageous mutation that wiped out others in an area (becomes fixed in a region).

All of these would push the "most recent" date further back.

But even if all mutations survived, the data from that paper would certainly not lead you to believe that humans are only 6,300 years old, and went through a bottleneck 4,300 years ago.

There's also DNA data on regional stone age people compared to the modern inhabitants that would blow out that view.

So, slevesque, ask yourself why it is that you find the Parsons' survey alone on some creationist sites, and not the other much larger survey that I've linked to.

Is it the sin of lying by omission?

The title of this thread is, ironically, secularists do not want the truth.


This message is a reply to:
 Message 77 by slevesque, posted 08-29-2010 7:05 PM slevesque has responded

Replies to this message:
 Message 81 by slevesque, posted 08-30-2010 11:03 AM bluegenes has responded

  
bluegenes
Member (Idle past 619 days)
Posts: 3119
From: U.K.
Joined: 01-24-2007


Message 84 of 85 (577823)
08-30-2010 3:11 PM
Reply to: Message 81 by slevesque
08-30-2010 11:03 AM


Re: Bring in more data, and calculate.
Hi, slevesque

slevesque writes:

I skimmed through it though, but found no reference to the minimum 10k age you are referring to. In your previous post, you said you calculated a 15k mininum a couple years back, is those two references one and the same ?

Those figures are from me. In the discussion, they put the figure for the four surveys (including Parsons') combined at 14 mutations for 1221 transmission events. Worked out relative to Parsons' time estimate, this gives you 15, 800 yrs.

The Icelandic survey on its own will give you a whopping 42,300 yrs.

sleve writes:

the paper says this in it's conclusion:

"We have argued that several of the explanations posited for a
systematic difference between phylogenetic and pedigree estimates of mutation rates are more limited than they might first appear to be. Pedigree estimates of this mutation rate are unbiased, regardless of the heterogeneity in rates—or of mutational hot spots—in the CR."

Doesn't this a bit contradict your claim on plausible explanations of the difference between pedigree and phylogeny-based estimates ?

No. What they're saying is that pedigree estimates are unbiased in determining the mutation rate, with which I agree.

But if you go on and read the rest carefully, you can see that they agree that the rate is unlikely to be a good indicator of what remains in the population long term, because of heterogeneity, which they say "undoubtedly exists".

For my purposes here, that doesn't matter, in the sense that we're talking about what the minimum age of the mtDNA Eve could be without considering the factors like heterogeneity, selection and drift (which would all make her older).

In other words, I'm rigging it to your advantage as a YEC, and pointing out that if those surveys were the only data you had to go on, because of the 15,800yr figure, you would say that the earth is very unlikely to be less than 10,000 yrs old, because that would require a 37% margin of error in your favour.

slevesque writes:

While searching for that paper on the creation.com database, I found this article: http://creation.com/...imp-human-dna-similarity-not-any-more

Which as a reference to the paper, but claims (if you read the relevant part of the article) that this paper in fact supports an age of 6500 years old.

I'm not a geneticist, like you seem to be, so maybe you could enlighten me on how you calculated your minimum age and how Dr. Dewitt could have gotten his 6,5k figure.

You're making my point for me here. Dr. DeWitt says:

quote:

A number of studies have demonstrated a remarkable similarity in the nuclear DNA and mtDNA among modern humans. In fact, the DNA sequences for all people are so similar that scientists generally conclude that there is a ‘recent single origin for modern humans, with general replacement of archaic populations.’8 To be fair, the estimates for a date of a ‘most recent common ancestor’ (MRCA) by evolutionists has this ‘recent single origin’ about 100,000–200,000 years ago, which is not recent by creationist standards. These estimates have been based on comparisons with chimpanzees and the assumption of a chimp/human common ancestor approximately 5 million years ago. In contrast, studies that have used pedigrees or generational mtDNA comparisons (6), (9), (10) have yielded a much more recent MRCA—even 6,500 years!(10).


He lists three papers, but that's all he says about them, and the "even 6,500 years" can only be passing reference to the Parsons paper, yet he misleadingly puts the (10) reference after it! Sin of omission. He could have done some maths, and said "from 6,500 years to 42,325 years". He also omits to mention heterogeneity, selection possibilities etc.

He appears to know his audience. They won't look at details, and won't understand what's going on.

sleve writes:

bluegenes writes:

There's also DNA data on regional stone age people compared to the modern inhabitants that would blow out that view.

You talking about Neanderthals ?

No. I mean us. If you're one of the YECs who considers Neanderthals to be descendents of Adam and Eve, then the sequencing of their DNA is an even bigger problem for you, as it would put the age of the earth way back, even at the Parsons mutation rate.

What I was referring to is samples of DNA taken from specimens like the oldest complete skeleton found on this island (9,200 years by our dating, but for you, he must be post-flood).

There are people in this region today in the same specific mtDNA haplogroup. Not much change. But a big change from people in the middle-east, and ancient skeletons in North America, for example.

sleve writes:

The date you talk about is your own calculation from their data. Dewitt seems to have calculated a different date from the same data. How can I know who's right ?

Read the paper carefully, and do the maths yourself.


This message is a reply to:
 Message 81 by slevesque, posted 08-30-2010 11:03 AM slevesque has not yet responded

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2019