I've only just noticed this thread, and it's peaked my interest.
People have already mentioned my favourites, so ... well I'll
just add my reasoning in
quote:
Originally posted by Robert:
Greetings:
Ah! yes - thank you Joz I understand your point now and I hope I did not frustrate you too much with my thickheadedness!
"Recent" in evolutionary terms could be millions of years I guess. So I assume that there is no current evidence of where horse (A) and donkey (B) came from? Some missing link that has eluded evolutionists after 150 years of looking? Or, has this missing link been found?
A lion and a tiger are both considered "cats". Yet a "Liger" is just as sterile as the mule. Close association producing (predominately)sterile offspring does not necesarily "prove" a "recent" branching off from one another. If they did produce a (predominately) fertile offspring then I would truly be amazed, and my respect for evolution would go up a notch.
You've asked for evidence ... but you still need to think on that
evidence.
Horses and Donkeys ARE closely related.
They cannot (or very rarely) produce fertile offspring.
If we go back into the fossil record we find a time when no modern
horses or donkeys have been found.
Those are the facts.
What could it mean ?
1) Horses and Donkeys were spontaneously created sometime in the
recent (geologically) past.
2) Populations of some previous horse/donkey-like animal were
separated, and natural selection lead to speciation.
3) ....
As I understand it even young earth creationists accept speciation.
In fact some of them rely on it to explain the numbers of animals
on Noah's Ark, and on the lack of modern day 'types' in the
fossil record.
1) Cannot even be tested.
2) Evolutionists and Creationists accept this as a possibility.
Clearly the divergence of these species has led to a situation in
which the populations almost-but-not-quite inter-breed.
Something within the genetic data of the populations has changed
such that offspring are (mainly) unable to breed.
My Conclusion:: Further genetic changes (and mutations DO occur
too)
could result in horse/donkey populations that cannot inter-breed.
If they produce pre-dominately fertile offspring they would not
be separated by much, and would cast no illumination onto the
mechanisms for evolution. Cross-breeds are no more likely to
lead to a new species that a pure-breed. Natural selection due
to environmental conditions does that.
quote:
Originally posted by Robert:
However, you cannot argue from possiblities when you are stating that evolution is a definite scientific fact.
Again, sorry for my seeming dimwittedness.
Robert
"Argument from possibility" is called Hypothesising ... and it's
how scientific enquiry often begins.
1) We observe some phenomena, and wonder how it came to be.
2) We create some scenarios.
3) We test the scenarios against evidence.
4) IF we find evidence contrary to the scenario we reject it & goto 2)
5) IF we find evidence to support the scenario we go back to 3)
There is evidence that horses and donkeys are closely related.
There is evidence that they are NOT AS closely related as
a horser is to another horse (say).
There is evidence that they are MORE closely related than chimps
are to orangutans.
These evidences support the idea that horses and donkeys are in the process of diverging.
More on 'macro'-evolution::
There are genes (alleles if you prefer) in modern day chickens, that
if active would cause the chicken to have a tail and teeth much
more like (say) a dinosaur or lizard.
Some process has, over time, favoured individuals in which these
genes are 'switched off'.
Result:: Genetic engineering could produce a back-step from chickens
to a lizard-like creature (possibly a dinosaur).
OK ... I haven't cited anything to support this, but I have seen
some geneticists on documentary programs who claim this to the case.
Single-Multi-Celled::
Have you heard of slime mould ?
Effectively this is a colony of single celled organisms which
so-operate to survive. They even show a primitive form of
group intelligence (do a yahoo search on "slime mould" for some
articles).
They have characteristics of plants AND animals.
Colony behaviour like this could be a clue to the step from
single to multi-celled life.
Natural selection could even be the nechanism for cell specialisation,
if we take the 'colony' to be the environmental driving force to
change. (Cells in the centre of the colony have different environment
to those on the outside edges, and so one would expect different
mutatations to be considered beneficial in different regions of
the colony).
THIS IS SUPPOSITION ON MY PART, and I do not apologise for that.
This is evidence which suggests a possible route to multi-celled
life and is consistent with the concepts of 'micro/macro'
evolution.