MK? I don't think we've had a debate. This should be interesting
What it is not defined as is universal common ancestry.
Once we have established that evolution occurs in the most general case, we can start to look at specific cases: speciation over time, speciation over genetic barriers, and the long-term consequences thereof.
i) given a single species of sexual reproducers, there will be only one species at any given time. However, the species at one time will not be the same species at some other distant time (either in the future or the past): the mutations accumulated in the population at one time cause the genome to be sufficiently different from the genome at some distant time, and hence the gametes of one time's population will not recognise the gametes of the other.
ii) same as (i), but this time introduce a barrier between the population, truncating them into two distinct, non-interbreedable groups. Over time, the set of mutations that appear in and proliferate through one group will not the same as that that in/through the other group. Over time, the two groups will become sufficiently different in genome that the gametes in one will not recognise the gametes in the other. I.e., speciation has occured.
iii) Repeat (ii) many times, and you will have a plethora of species all ultimately descended from one original species. In this way, evolution directly leads to common ancestry.
Of course, while we can flip the model around (if one species today can become many species in the future, then the many species today may have come from one species in the past), this is only a hypothesis as to the origin of the diveristy of modern life. We still have to subject it to the rigourous testing that any other hypothesis goes through.
But my point is that common descent follows directly from this simple notion of evolution. The evidence for whether this in fact happened, I think, we will discuss further down.
That would work real great in court, shouting at the jury, 'our lack of proof is meaningless'.
Judical systems in the West have countered for this: evidence must be presented, rather than proof demonstrated. We talk of proof
beyond reasonable doubt. There is always the chance that some omnipotent entity changed things to look exactly like person A killed person B, when in fact A was asleep at the time, but this possibility is so remote that we are quite safe to dismiss it.
Likewise, while scientists don't rule out the possibility of magic gnomes as the cause of gravity, the evidence in favour of Einstein's theory allows us to dismiss it as merely an experiment in technicalities (as indeed it is).
In any case, my point was that claiming "You can't prove it, therefore it's not science" is a false claim;
nothing in science is proven.
Evolutionary theory as defined by the change of alleles is not a theory, it's a quantifiable and quantifiable phenomenon.
There is a difference between evolution the phenomenon, and evolution the theory: the former is a known biological phenomenon (hence the name), and the latter is an umberella term for the theories explaining how evolution works in practice (genetics, etc) and how it evolution in turn explains other things (similarities between taxa, etc).
However, it is not boundless as you assume, see my signature.
Your signiture simply asserts that there are some bounds beyond which one particular species genome will not go. What evidence if there for such boundaries?
Then you have seen micro evolutionary adaptations and recombinations, if you are talking about speciation.
Correct. The mutations accumulated in one group became sufficiently large in number such that the gametes of the other group didn't recognise the gametes of the first group any more. I.e., they couldn't interbreed any more. I.e., they were different species.
Please tell me you don't have a degree in advanced physics, I would be afraid to go to sleep at night.
I haven't got my degree yet, but if all goes according to the master plan, I'll have a masters in theoretical physics, which includes an in-depth knowledge of quantum mechanics. Hoo hah!
I just picked one out at random since this Darwinian mythology is so easy to pick apart:
The apparently sudden appearance of relatively modern flowers in the fossil record posed such a problem for the theory of evolution that it was called an "abominable mystery" by Charles Darwin. Recently discovered angiosperm fossils such as Archaefructus, along with further discoveries of fossil gymnosperms, suggest how angiosperm characteristics may have been acquired in a series of steps.
Flower Evolution
It's an 'abominable mystery' but now that we have some angiosperm fossils it may have been in a series of steps. Sounds like ironclad evidence to me, hope they got the Nobel Prize for that one.
Is that sarcasm? You'd make a good Briton.
In any case, that wikipedia article is not a scientific journal, and only gives an outline of the current consensus on how flowers evolved. Why the evidence suggests such a model is disussed in the relevant papers.
I have a theory, you have been nipping at the eggnog a bit too much today.
Eggnog?
*
wikis*
That sounds disgusting
People actually drink this?
Newsflash, there were a very limited number of species on Noah's Ark.
Says who? The Creationists who vhemently deny the existance of speciation would beg to differ.
There are how many different species in the world today? Do you really think that speciation events are a big problem for Creationism.
Well, yes: everything takes after its kind, right?
I Rather thought Mark was above this sort of thing but it appears I am wrong.
