Cladistics and "Eclecticism"

[P.Hovenkamp]

At 12:31 PM 2/4/02 -0500, Thomas DiBenedetto wrote:

(...)
>seem not to take those points into account. To briefly summarize: Ancestral
>taxa do not go extinct unless they go extinct; i.e. unless all the organisms
>die. Ancestral taxa become higher taxa when some of their descendants become
>historically isolated from others of their descendants, i.e when the lineage
>bifurcates. The only thing that comes to an end at the point of bifurcation,
>is the simple fact that the ancestral taxon was a terminal branch in the
>lineage system, and thus ranked as a species. After bifurcation, it's status
>as a species-level taxon is finished. It's life as higher level taxon is
>just beginning. How can this be considered "extinction"?

Two questions, well, three actually:
1. If a group of people (say, a mixed group of 100 men, women and children)
embarked on a spaceship and were to settle on Mars - would that effectively
split Homo sapiens into two species (assuming contact would be scarce and
limited to raw materials, not frozen sperm etc.) the moment the spaceship
took off?
2. If a group of people (say, a mixed group of 100 men, women and children)
embarked on a plane which later crashed into a high mountain in the Andes
(alas, no survivors) - would the situation to us survivors on the ground
(and in other planes) be different in any way from the situation we would
have had in the first case?
3. Considering the fact that (2) is a fairly common occurrence, are we
still in the same species as we were this time last year?

Peter Hovenkamp