We are now in a position to understand why phylogenetic trees
never propose LIVING species as direct descendants of one another.
The DNA evidence is damning for any such real construction,
because the Genome of EVERY species shows plain 'cross-mixture',
unique to almost every triplet of species chosen.
All ancestors must be hypothetical any systems which attempt
to give credibility to the hypothesis of No DNA Transfer between species.
All ancestors and nodes must be hypothetical in nature,
and based on key assumptions like the impossibility of inter-species DNA transfer.
But this also means that all primary DNA-based phylogenetic trees
can only be one level deep. Further backward constructions must
continue building upon already hypothetical constructions, with
less and less reliability and certainty.
Such hypothetical phylogenetic trees must make connections based
on a kind of 'mutation Parsimony' which attempts to minimize the
number of mutations. This itself is the best policy, but it cannot be
assumed that genetic mutations have always travelled the simplest path.
But the distances portrayed on these reconstructed 'trees'
have another glaring fault. They assume that mutation rates are
more or less constant, predictable, and can be used as reliable indicators
of 'evolutionary distance' and even estimated time.
Thus a typical phylogenetic tree will indicate the number of mutations
using a distance scale, inferring also relative timing of evolutionary steps
of hypothetical speciation.
Such a tree is very misleading however, because the Theory of Evolution itself demands that real preserved mutations be transferred at widely varying rates,
according to the environmental factors driving Natural Selection.
In reality, these phylogenetic trees constructed using DNA information
have been artificially extended and made to look more 3-dimensional,
when in actual fact they are quite flat and unable to comment on the actual historical rates of transmitted DNA mutations and timings of speciation events.
A less misleading presentation of the same data would look like this:
Here we see what the DNA evidence is really saying:
(1) The tree is only one generation deep as far as living organisms,
because real organisms cannot be placed in a credible descent tree.
(2) The number of mutations counted along hypothetical routes,
back to hypothetical 'nodes' of hypothetical ancestors has no precise
meaning in terms of time or even mutation rates.
This is because according to the theory, only Natural Selection
can determine which mutations become passed on and what the
timing will be.