>>11343667Not at all, you are confusing how these things fit together completely:
IF
- You assume that evolution operates at the level of bases at a marginally stable rate
THEN
- Genetic distance can be used as a proxy for age
Not the other way around, neither is proven, and the age of distant members of the same species isn't actually known either (it's estimated by diverse means like carbon dating in the environment of the sample when possible, which is used to estimate the rate of change parameters).
Look at phylogeny papers and realize it's all pretty bullshitty. There are many even simple mechanisms by which we expect the assumptions to break, too. For example most models use single-AA symmetric mutation probability, but instead of stopping there with the simplification, they also assume that GC and AT mutate at the same rate, respectively. In reality, not only should you be looking at stretches, but mutation rates depend on sites (functional are less likely to mutate in theory - again, IF we assume that functional means it's critical to life and without it the specimen will fail to reproduce THEN we can also assume that functional is less likely to mutate - with no proof, just correlation), local composition (CpG islands), 2D, 3D and 4D structures (cf: covariation studies - one mutation WILL as a general rule induce multiple additional compensatory mutations but not always, which impacts simplified models like those used in practice), etc. None of this is taken care of in most phylogenic studies, except for location (usually they do phylogeny not on whole genome but only a specific part because they think it will mutate more regularly - namely something very functional that is probably very old).
Additionally, you can do age estimation with many other things, like gDNA vs cDNA, which yields completely different results.
