[bobdsmith]

Lateral transfer is a scientific fact and renders the idea of universal common descent clearly false

As long as vertical transfer still exists, the existance of horizontal transfer does not render common descent false.

Even absent this fact, the vast lack of evidence about the path by which early life developed should preclude any consensus about the existence or not of a common ancestor of all present life

I think this is a seperate question from whether common descent is a fact. Common descent of all life is just an extrapolation made from the evidence of common descent of some species. Noone can be certain that every species alive today is due to common descent.

Then again universal gravitation is an extrapolation made from the evidence of the law of gravity in some areas of the universe. Noone can be sure that all the universe acts under the law of gravity.

[edsheppa]

As long as vertical transfer still exists, the existance of horizontal transfer does not render common descent false.

If genetic material is swapped freely between species, there need not be a single founding species to all present life.

I think [uncertainty about biogenesis] is a seperate question from whether common descent is a fact.

It bears on bearing on the question directly. Suppose that life arose twice or more independently and that these several populations could swap genetic material. Now one can conceive of a tracing the ancestry of all present species and never finding a single common ancestor.

Noone can be certain that every species alive today is due to common descent.

I thought it wasn't a question of certainty but rather the perversity of doubting, that this is a difference between absolute and scientific fact.