The time scale of the bottleneck?


(George Brooks) #41

@pevaquark

If i have mis-stated some obscure element please let know what or where.

It was my understanding that Buggs and Venema have agreed that there is no indication of a single pair bottlencek any time within 700,000 yrs(though ive read summations that use 500k yrs instead) of the present.

The 700k (or 500k?) represents the wall of noise that makes it impossible to know what could be or couldnt be true further back than 700k years.


#42

@aarceng

My point was there wasn’t a single sentence. You have to read Richard’s final post in the context of the entire conversation that took place. Do you understand the significance of Richard dropping any reference to a lower bound? He has always tried to minimize the % of similarity and is widely quoted on anti-evolution websites as an authoritative source for the smallest % possible. To even admit that 95% was a possibility is a major change in his position.


(Matthew Pevarnik) #43

As @Swamidass eloquently outlines, looking at human variation alone doesn’t grant a miraculous bottleneck anytime in the past 500 kya (looking at TMR4A). But really, the idea of TMR4A is rather ridiculous from a purely scientific perspective. Not that the idea itself is not scientifically sound, it very much is and can be calculated, but you would never have two individuals that have two alleles at every loci that are different from their spouse and thus the timeliness of such a bottleneck (if there was one) would be even further in the past. Hence its more likely that a bottleneck (if there was one) would be closer to the average TMRCA.

But that’s only looking at human variation, not any kind of trans species evidence like shared polymorphisms or incomplete lineage sorting which also provide population estimates of populations and at least the latter do not reveal any bottlenecks at all going back much further.


(George Brooks) #44

The point of 500,000 yrs is not that a bottleneck MUST have happened then… but that “noise” prevents science from EXCLUDING a bottleneck prior to 500,000 yrs.

I always thought it odd that Buggs would be so interested in a time-frame well outside of the Biblical limits.


(Matthew Pevarnik) #45

What are the Biblical limits in an old earth scenario? Most Old Earth concordists are fine with adding ages and finding gaps in the listed geneologies and maybe some place Adam and Eve’s special creation 50,000 some years ago. Ann Gauger though seems perfectly fine going back several million years and finds it consistent with her understanding of essential Catholic doctrines.


(Mitchell W McKain) #46

As explained in the other thread, I totally support the conclusion of the scientific community that we have 98.8% similarity of DNA with chimpanzees. However…

  1. This can be a little misleading because small genetic differences do not equal small physiological differences.
  2. This certainly does not mean that chimpanzees are 98.8% human. Our genetics is not where our humanity is to be found. We are primarily meme organisms rather than gene organisms – human minds not primate bodies. It is the information in our linguistic communication which has the more important inheritance for the next generation.

The very concrete difference this makes is actually quite simple. If like the planet of the apes movies, chimps acquired the power of speech and could thus inherit all of our ideas and learning, should they still be considered animals? Surely reasonable people would see that as a terrible mistake.

  1. Our ancestors from 500,000 years ago are not even the homo-sapiens species, which evolved during the period 100,000 to 300,000 years ago. Modern humans are only seen after 100,000 years ago, but the subspecies Neanderthal is found considerably earlier.

(Chris) #47

Sorry @Bill_II, but you are mistaken. You can find Richard’s final statement on his blog here.

He sticks with his original figures and says “I predict that the 95% figure will prove to be wrong, because (on the basis of my comparison of the PanTro4 and PanTro6 alignments to Hg38) I think that the CNV differences are here to stay, and I doubt that all of the currently unaligned or unsequenced regions of the human genome will prove to all be 95% the same as the chimpanzee genome.” [my emph]


(Chris) #48

I assume you are referring to where @glipsnort says,

The human genome is ~3.2 billion base pairs so that means 0.72% to 1.22% single-base substitutions when comparing human and chimpanzee genomes. (99.3% - 98.8% similarity)

So, from your reference, the answer to my question is that any less than 98.8% similarity is inconsistent with the evolution hypothesis. 95% is 4 times too much difference (5%/1.22%). Evolution is a faith because common ancestry doesn’t add up.


(Phil) #49

Chris, as I recall, the percentage is very dependent on the methodology used to calculate it, so whether it is 89% or 98% is really irrelevant, unless you are using those numbers as a tool. In that case, they become useful. For example, it would be of interest to compare human to chimp, and chimp to gorilla, and chimp to orangutan to put it in context, but one isolated comparison tells you very little.


(Matthew Pevarnik) #50

So a ‘faith’ to you is something that doesn’t have any evidence to support it? Or even worse even despite evidence to the contrary one still proposes their model by ‘faith.’

A special creation model like yours is a faith based model that doesn’t have any mechanisms or predictions beyond God just did stuff. I have showed you now multiple times the types of differences we see can be explained by random mutations among human to human and between human and chimpanzee. Did you not understand the graph that I put above?


(Chris) #51

So rather than responding to the substance of my post your are picking on a phrase that actually comes from your post. Please respond to the main question; how much difference is too much? From your reference it would seem that 5% difference (95% similarity) is already 4 times more than can be supported by evolution theory.


(Chris) #52

In which case 98% similarity is not evidence in favour of humans and chimps having a common ancestor within the last ~7 million years. Is that what you’re trying to say?


(Phil) #53

No, I am saying you have to compare apples to apples. 98% may be evidence, or may not depending on how it is determined, and how it compares to other animals using the same measure.


(Steve Schaffner) #54

Skip the genome size and just calculate the rate of difference from the mutation rate and the approximate number of generations. The range is 0.76% to 1.29%.

You seem to have missed something. The range of single base differences is predicted to lie between 0.76% and 1.29% (roughly). The observed rate of single base differences between the species is 1.23%. To predict the total genetic difference between the species requires a good estimate of the mutation rate for insertions and deletions, including large ones, which we do not have. These mutations are less frequent than single-base substitutions but contribute more total sequence change.


(Chris) #55

@glipsnort, thanks for clarifying that.


(Shawn T Murphy) #56

Adam and Eve were incarnated as humans on Earth the first time about 200,000 years ago. But these early humans were hunters and often cannibals, as such they did not have much language or culture. This came much later.

It was the abrupt global warming that occurred around 8,500 BC, that flooded the inhabited delta regions and wiped out those who were not prepared for the rising waters. But Noah was warned enough in advance to be saved. Only after the hunters/cannibals were wiped out, was a farming/animal husbandry culture able to be established. This is where language and culture started to establish a civilization.

Global%20Warming%20Temp


(Matthew Pevarnik) #57

They were what?

And what do you think this graph is telling you about a massive rise in sea level? Presumably the black curve is the average temperature anomaly and I have no idea what the different colors are meant to represent but it doesn’t show anything related to a massive rise in sea level that would have killed all those barbaric hunter folks but preserved the more civilized like farmer Noah.

Here is a graph from Australia for example:

And from various parts of the world (South America/Central America/etc.):
image

There is no sudden spike at 8,500 years ago but a gradual rising of sea levels over several thousands of years.


(Mitchell W McKain) #58

The LDS (mormons) think like that. They believe we were all born in heaven an then incarnated afterwards. But wouldn’t be too surprise to learn that there are some other groups who think in this way and some might even be Christian (in the creed of Nicea 325 AD sense).

Obviously I have made it very clear that I do not agree with this – not with pre-existence and not with putting Adam and Eve that early.

That sounds possible. However, the Bible puts the flood around 2300 BC and puts Adam and Eve around 4000 BC. I think you can still take the story it tells pretty seriously if you think this isn’t literally accurate. But I see no reason to exclude the possibility that it is correct, so I would place these two events with a time range like 4,000-10,000 BC for Adam and Eve, and 2,300-8000 BC for the flood (a local one which wiped out early human civilization), or something like that.


(Shawn T Murphy) #59

Matthew, I did not say there was peak 8,500 years ago, but that the delta regions flooded 10,500 years ago, or 8,500 BC. Your graphs show a 120 meter rise in the level of the oceans, starting to accelerate15,000 years ago and ending 7,000 years ago. Yes, the flood could be placed anywhere in the is range, but never younger than 6,000 years ago. It is not the slow rise of the ocean that was deadly, but the flash flooding coming from the irregular release of water from the melting glaciers. Australia did not experience the dangers that the near east did in this respect. As the ice receded in Eurasia, the dearly regions were deadly.

The reference for the 8,500 BC number comes from the work of Heinz Blum. (“Erwaermung bewirkte die Sintflut.” Museion 2000,3/1994, 40-46. Print) This is based on many factors, including the oldest bricks found in the near east have been dated at 8,300 BC - the first signs of constructed civilization.


(Shawn T Murphy) #60

Dear Mitchell, the Bible does not say anything about time, but rather doctrine has created these dates that you are quoting. I thought that Biologos was the intersections between the Bible and Biology? Biology has dated the convergence of genetics to 100,000 to 200,000 years ago, with no fundamental change in genetics from then until now in humanity. Are you open to alternative interpretations of the numbers in the Bible that match what biology and anthropology are showing us?