One way to start is look at mtDNA. The mutation rate as measured directly by Parsons & al decades ago put the most recent female common ancestor of all humans on the planet today at between 6000-12000 years ago. On average, people have ~20 mutation difference to the “consensus” sequence (Eve mtDNA). The 400 000 years figure proposed by mainstream science is based on chimpanzee common ancestry model, and ignores the direct measurement of mutation rate.
Y-Chromosome can also be used to date our most recent paternal ancestor, however the DNA is much longer (15Mb if I remember correctly, 16kb for mtDNA) so it’s much harder to evaluate a consensus sequence and count the total amount of mutation. Recent measurements however indicate a range of a few thousands years, not hundred of thousands.
“Calibrating the Mitochondrial Clock” - Ann Gibbons Page 4 Using the rate directly measured by Parsons
“Mitochondrial DNA sequence heteroplasmy in the Grand Duke of Russia Georgij Romanov establishes the authenticity of the remains of Tsar Nicholas II.” Parsons & al.
“How rapidly does the human mitochondrial genome evolve?” Howell & al
“A high observed substitution rate in the human mitochondrial DNA control region.” Parsons TJ
Basically the mutation rate is observed to give mtEve around 6000 years old, but there’s a lot of panic going on to try explaining this high rate since the evolutionist model place her at 400 000 years ago.
The Y-Chromosome has been studied much less, this is an article by a creationist researcher :
“Evidence for a Human Y Chromosome Molecular Clock: Pedigree-Based Mutation Rates Suggest a 4,500-Year History for Human Paternal Inheritance” - Nathaniel T. Jeanson, Ashley D. Holland
There’s only a few other studies that tries to determine a mutation rate but they only compare small portions of the y-chromosome.
Another point evolutionists hammer on is that mtEve was not the only woman around at the time but only her lineage survived (we observe a single lineage today), however this is easily disproven with simple statistics. If there’s many mtDNA lineage at one point, after 2-3 generations it becomes extremely unlikely that one disappears, I can try to find an article I saw on this subject.
Here’s from a study that looked at the mutations between father and son Y-chromosome DNA to calculate a mutation rate :
“The number of [father-son Y-chromosome] differences was approximately 10 fold higher than the expected number […] This finding prompted us to explore additionnal filters.” -
“A recent bottleneck of Y chromosome diversity coincides with a global change in culture” 2015
So they basically deleted the data that didn’t fit the 200 000 years figure for Y-chromosome Adam because the measured mutation rate put him around ~5000 years ago.
To begin though, it’s obvious that you find AiG a credible source of scientific information and have a commitment to Young Earth creationism from the get go. That may make anchoring bias a big challenge for us moving forward in this conversation:
This statement is very incorrect for example. There’s not a lot panic going around communities of geneticists who already know that common ancestry is a fact. I’m not sure what you were talking about when you say that the evolutionist model puts mitochondrial eve at 400,000 years ago.
There is no specific time when anyone would put a mitochondrial eve besides those that believe in special creation. For example, if you include Neanderthals, mitochondrial eve gets pushed backwards in time. She gets pushed backwards even further in time if you include Denisovans. Or this person can get pushed more recent if you talk about all humans alive today. if you take a subset of all humans alive today then the answer becomes even more recent.
So maybe before we try to quibble with things that you’re probably just repeating from answers in Genesis, maybe we can try to be specific on what it is that scientists are saying.
In other words Matthew, the smaller the non-random, recent sample the more recent their Eve and vice versa. As the genetic diversity for our population is low compared with other great apes, we must have gone through a recent bottleneck or two (there are a couple of candidates 150 Kya and half that), of less than 10,000.
Is there many human mtDNA lineages today that I am not aware of ? You know very well that I am talking about the most RECENT matrilinear ancestor, which is dated and the datation is directly linked to mutation rate.
We just need to compare mtDNA sequences from people all over the planet, find the consensus sequence, count the average differences from today’s population to this consensus sequence (~20 mutations in average), then divide by the mutation rate per generation. You get the number of generations to mtEve, a highschooler can understand this.
There have been studies by Parsons & al. to directly determine this mutation rate, which I cited, but as I said the author simply discarded the rate they found and said :“this rate places mtEve at 6000 years ago, obviously nobody think that’s the case” - Ann Gibbons, citing the article by Parson.
If you look at modern humans you get a TMRCA between 124-170 kya. If you include Neanderthal mitochondrial DNA, you push back the TMRCA between 360-468 kya. If you include Denisovans you go back even further in time. You have to account for this data as well @jesse_a_b.
But why claim the 124-170 thousand years when the actual measured mutation rate say this number should be 6000 years ? And this graph supposes a starting point based on evolution theory (just like the dating), the data itself is very different.
Here’s a modern mtDNA map with distances showing the mutations difference, seems like the official starting point is very arbitrary :
The 124-170 thousand years comes from looking at the rest of the mitochondrial genome. There are small control regions within the mitochondrial genome that change a lot faster than the rest of the mit genome. What AiG and other creationists have done is take the slower rate of change in the rest of the mit genome and applied it to the control regions that change a lot faster. This is dishonest. It is known that the control regions change faster, so you can’t use the rates from elsewhere on these regions.
Convenient excuse. And how did they evaluate what were these “control regions” and how much faster the mutation rate was there ?
They compared mtDNA sequences, found mutations, then claim these mutations occurred in high mutation rate zones. But is there any evidence of it, apart from the “need” to bring down the general mutation rate to make it fit to their evolutionary model ?
“The mutation rate is also thought to be faster in recent times” - Wikipedia
Convenient ! Where’s the data supporting it tho ?
Like I said about the Y-chromosome, the mutation rate measured was “too high”, what did the researcher do ? They added more filters to their data to bring it back at a lower rate. Dishonest.
Here is from “Characterizing the Time Dependency of Human Mitochondrial DNA Mutation
“Previous research has established a discrepancy of nearly an order of magnitude between pedigree-based and phylogenybased (human vs. chimpanzee) estimates of the mitochondrial DNA (mtDNA) control region mutation rate. We characterize the time dependency of the human mitochondrial hypervariable region one mutation rate by generating 14 new phylogeny-based mutation rate estimates using within-human comparisons and archaeological dates. Rate estimates based on population events between 15,000 and 50,000 years ago are at least 2-fold lower than pedigree-based estimates.
These within-human estimates are also higher than estimates generated from phylogeny-based human–chimpanzee comparisons. Our new estimates establish a rapid decay in evolutionary mutation rate between approximately 2,500 and 50,000 years ago and a slow decay from 50,000 to 6 Ma.”
You can see how hard they are trying to explain away the actual observations to forcefully fit the 6 Ma common ancestor with chimpanzee.
This is not a claim, this is a quote : "The number of [father-son Y-chromosome] differences was approximately 10 fold higher than the expected number […] This finding prompted us to explore additionnal filters.” - “A recent bottleneck of Y chromosome diversity coincides with a global change in culture” 2015
Here’s why they call it “hypervariable segments” in mtDNA : almost 80% of mtDNA among all humans today is identical, that’s what you would expect to observe if you start from a recent common ancestor.
But if you assume the common ancestor is way further back in time, the fact most of the mtDNA remains identical “must” mean that these sections are less variable. But how can we prove this ?