Yet another nonfunctional example of evidence for common descent is
given by retrogenes.  Retrogenes are molecular remnants of a past
parasitic viral infection.  Occasionally, copies of a retrovirus genome
are found in its host's genome, and these retroviral gene copies are
called retrogenes.  Retroviruses (like the AIDS virus or HTLV1, which
causes a form of leukemia) make a DNA copy of their own viral genome and
insert it into their host's genome.  If this happens to a germ line cell
(i.e. the sperm or egg cells) the retroviral DNA will be inherited by
descendants of the host.  Again, this process is rare and fairly random,
so finding retrogenes in identical chromosomal positions of two
different species strongly indicates common ancestry.

Confirmation:

There are three different instances of common retrogene insertions
between chimps and humans.  Another example is provided by the Felidae
(i.e. cats).  The standard phylogenetic tree has small cats diverging
later than large cats, with the blackfooted cat being the first of the
small cats to diverge.  All small cats (i.e. the jungle cat, European
wildcat, sand cat, African wildcat, blackfooted cat, and domestic cat)
share a specific retroviral gene insertion.  In contrast, the cat
lineages that diverged before the small cat lineage (i.e. the lion,
cheetah, and leopard) and all other carnivores lack this retrogene.

Potential Falsification:

It is incredibly unlikely, macroevolutionarily, that the cheetah, or
some other mammal (e.g. dogs, cow, etc.), could have this same retrogene
in the same chromosomal location.  Conversely, it is also very unlikely,
given common descent, that one or more of the small cats which diverged
after the blackfooted cat would lack it.

This is a follow-up to my previous posts:

Proof of Macroevolution: (1)  The fundamental unity of life.
http://www.deja.com/getdoc.xp?AN=514524093

Proof of Macroevolution: (2)  A "nested" hierarchical organization of
species
http://www.deja.com/getdoc.xp?AN=515312382

Proof of Macroevolution: (3)  Convergence of independent phylogenies.
http://www.deja.com/getdoc.xp?AN=515638573

Proof of Macroevolution: (4)  Morphologies of predicted common
ancestors.
http://www.deja.com/getdoc.xp?AN=532866179

Proof of Macroevolution: (5)  Chronological order of predicted common
ancestors.
http://www.deja.com/getdoc.xp?AN=533154861

Proof of Macroevolution: (6)  Anatomical vestigial characters.
http://www.deja.com/getdoc.xp?AN=533264263

Proof of Macroevolution: (7)  Molecular vestigial characters.
http://www.deja.com/getdoc.xp?AN=534527605

Proof of Macroevolution: (8)  Evidence from Ontogeny.
http://www.deja.com/getdoc.xp?AN=537814090

Proof of Macroevolution: (9)  Present biogeography
http://www.deja.com/getdoc.xp?AN=543215607

Proof of Macroevolution: (10)  Past biogeography.
http://www.deja.com/getdoc.xp?AN=543382759

Proof of Macroevolution: (11)  Anatomical paralogy.
http://www.deja.com/getdoc.xp?AN=543624826

Proof of Macroevolution: (12)  Molecular paralogy.
http://www.deja.com/getdoc.xp?AN=544177242

Proof of Macroevolution: (13)  Anatomical convergence.
http://www.deja.com/getdoc.xp?AN=544688616

Proof of Macroevolution: (14)  Molecular convergence.
http://www.deja.com/getdoc.xp?AN=546155624

Proof of Macroevolution: (15)  Anatomical suboptimal function.
http://www.deja.com/getdoc.xp?AN=547038036

Proof of Macroevolution: (16)  Molecular suboptimal function.
http://www.deja.com/getdoc.xp?AN=550425113

Proof of Macroevolution: (17)  Protein functional redundancy.
http://www.deja.com/getdoc.xp?AN=578109016

Proof of Macroevolution: (18)  Functional molecular evidence - DNA
coding
http://www.deja.com/getdoc.xp?AN=578539856

Proof of Macroevolution: (19)  Nonfunctional molecular evidence -
transposons.
http://www.deja.com/getdoc.xp?AN=580095313

Proof of Macroevolution: (20)  Nonfunctional molecular evidence -
pseudogenes.
http://www.deja.com/getdoc.xp?AN=588612456