This article is about mitochondrial DNA, and the discovery some years back, of a 'marker', that was passed down to daughters, tracing actual descent. It leads to the Most Recent Common Ancestor (MRCA), in genetic lines, and provides hard science for timelines, descent, and relationships.
From wiki:
In human genetics, the Mitochondrial Eve (also mt-Eve, mt-MRCA) is the matrilineal most recent common ancestor (MRCA) of all currently living humans, i.e., the most recent woman from whom all living humans descend in an unbroken line purely through their mothers, and through the mothers of those mothers, back until all lines converge on one woman.
It is a problem for the theory of common descent, as it clearly shows the lines of descent in a particular genetic haplogroup.
For example, we can trace the descendancy in canids.. dogs, wolves, coyotes.. even though they have some differences morphologically, they show evidence of descent, and share a common mother.. the Most Recent Common Ancestor that they ALL descended from.
This marker does not cross over to other speculated ancestors. Humans, for example, share a common MRCA, which shows we all descended from the same mother, and did not evolve seperately, in different geological regions, as was once proposed. Neanderthals were human. Pygmies, Mongols, Eskimos, Europeans, Africans.. every race, region and body type of human beings all share the MRCA.. a marker showing descendancy and relationship with all other humans. Chimps, monkeys, apes, or any other speculated 'cousins', do not have this HUMAN MRCA marker, but their own, showing their lines of descent.
So, while the dingo, dog, wolf and coyote can be traced to a MRCA, humans, apes, and monkeys cannot. Each genetic haplogroup has its own MRCA, and they do not intersect or overlap. There is no evidence of descent.
From wiki:
Mitochondrial DNA is the small circular chromosome found inside mitochondria. These organelles found in cells have often been called the powerhouse of the cell. The mitochondria, and thus mitochondrial DNA, are passed almost exclusively from mother to offspring through the egg cell.
...
Mitochondrial DNA was discovered in the 1960s by Margit M. K. Nass and Sylvan Nass by electron microscopy as DNase-sensitive threads inside mitochondria, and by Ellen Haslbrunner, Hans Tuppy and Gottfried Schatz by biochemical assays on highly purified mitochondrial fractions.
Time to most recent common ancestor, aka 'mitochondrial clock'.
Source:
News this Week | Science
Regardless of the cause, evolutionists are most concerned about the effect of a faster mutation rate.
For example, researchers have calculated that "mitochondrial Eve"--the woman whose mtDNA was ancestral to that in all living people--lived 100,000 to 200,000 years ago in Africa. Using the new
clock, she would be a mere 6000 years old.
...
The most widely used mutation rate for noncoding human mtDNA relies on estimates of the date when humans and chimpanzees shared a common ancestor, taken to be 5 million years ago. That date is based on counting the mtDNA and protein differences between all the great apes and timing their divergence using dates from fossils of one great ape's ancestor. In humans, this yields a rate of about one mutation every 300 to 600 generations, or one every 6000 to 12,000 years..
..aka, circular reasoning.. you presume the descendancy of apes and humans, THEN calculate a 'rate!'. It is convenient if the data fits within (and is based upon) the preconceived assumptions.
The researchers sequenced 610 base pairs of the mtDNA control region in 357 individuals from 134 different families, representing 327 generational events, or times that mothers passed on mtDNA to their offspring. Evolutionary studies led them to expect about one mutation in 600 generations (one every 12,000 years). So they were “stunned” to find 10 base-pair changes, which gave them a rate of one mutation every 40 generations, or one every 800 years. The data were published last year in Nature Genetics, and the rate has held up as the number of families has doubled..
So the ACTUAL, MEASURED rates, from real life data and evidence, is suspected, while the ASSUMPTIONS are clung to with dogmatic certainty. The measured, scientifically based rate is dismissed, in favor of the assumed and believed rate that fits the status quo dogma.
Mitochondrial DNA carries a genetic indicator of matrilineal descent, and can trace that descendancy all the way back, to a Most Recent Common Ancestor.. the mt-MRCA. It is ONLY passed on by FEMALES.. mother to daughter. The males get it from their mother, but it stops there. Only the DAUGHTER can pass it on.
For this reason, the mt-MRCA has been called 'mitochondrial eve,' ..not because the crafters of the phrase believe in the Genesis account of human origins, but as a cultural reference, to western civilization. Most people in western civilization catch the reference to a single 'Mother of all Humanity.'
The significance of the discovery of the mt-MRCA is often ignored and overlooked:
1. All of humanity, alive and dead, that has testable dna samples, can be traced to this 'mitochondrial eve'. She is the only, single human ancestor we can identify, and all of us descended from her.
2. Neanderthal, Pygmies, Eskimos, Norwegians, Aborigines.. any and ALL human people groups, alive or dead (with traceable dna), are descended from this mitochondrial eve.
3. This 'marker', within the mtDNA, is also present in other organisms, and THEIR ancestral lineage can also be traced. Canids have clear lines of descent, from the original mt-MRCA, in their respective haplogroup/clade/phylogenetic type.
4. This mitochondrial 'marker' does NOT cross genetic boundaries, but is exclusive to the particular haplogroup. Apes and chimps do not have the human mt-MRCA, nor do humans have any indication of sharing common ancestry with ANY other species/clade/phylogenetic type. Humans are descended from humans. Apes from apes, canids from canids, equids from equids.
The discovery of the matrilineal ancestry 'indicator', in the mtDNA has been a scientific boon. It has refuted many assumptions and beliefs, that are abundant in the theory of universal common ancestry, and are a problem for those who believe this theory.
I predict as more information is discovered, especially in genetics, the theory of common ancestry will join the flat earth, the 4 humours, and spontaneous generation, in the dustbin of debunked scientific theories. It has become a Religious Belief, complete with fanatical True Believers, who defend it with jihadist zeal, but they are unable to debate the science behind their beliefs.
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