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De-volution? (Life Sciences)
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Grant



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Even the polar bear/brown bear story is very dubious. See this article from the New York Times in which a DNA analysis has shown that they split a very long time ago;

https://www.nytimes.com/2012/04/20/science/polar-bears-did-not-descend-from-brown-bears-dna-study-indicates.html

Polar bears, long thought to have branched off relatively recently from brown bears, developing their white coats, webbed paws and other adaptations over the last 150,000 years or so to cope with life on Arctic Sea ice, are not descended from brown bears, scientists report.

Instead, according to a research team that looked at DNA samples from the two species and from black bears, the brown bear and polar bear ancestral lines have a common ancestor and split about 600,000 years ago.


But mysteries remain, some more puzzling than ever. Why does the mitochondrial DNA suggest a much more recent origin for polar bears? Dr. Hailer suggests that it is evidence not of the origin of the bears, but of interbreeding between polar and brown bears long after they evolved, perhaps when the polar bears were driven to land because of sea ice loss.
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Mick Harper
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Well, I wasn't going to post up the next instalment until tomorrow but given your intervention, I'll put this up now

Harriet Vered
Nice try but it is absolutely certain that brown bears and polar bears can interbreed and therefore are not separate species

Jasem Kashani
Flawed logic - you asked for an ancestor! If they are an ancestor - they will clearly be of the same genus. Inter-species breeding is common! The fact is, polar bears evolved from brown bears around 150,000 years ago. They are distinct animals now. A lion can breed with a tiger - does that mean lions and tigers are the same species? Of course not! They are however of the same Genus. How about Darwin finches?

How is Hatty ("The Cockroach") Vered gonna get out of this one?
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Mick Harper
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Rather long-windedly but it is, as they said in St Louis in 1904, exposition time

Harriet Vered
Let's look at the cases you've highlighted. Speciation is, as you say, complicated but polar bears and brown bears produce viable offspring while ‘lygers’ are normally sterile. But this is not the central point. You were tasked with naming an example of a ‘living ancestor’. Which one is ancestral, the lion or the tiger? Usual answer: “Neither, it may be smilodon or it may be an unfound fossil cat.” But either way it is not ‘living’.

We’ve got several million living species in the world today to choose from and, by Darwinian definition, ancestor and evolved species must co-exist for a period of time, so at the very least there should be tens of thousands of examples out there, and you only have to name one (or rather two). You can start with the finches if you like, there are enough of them, but you need to name which one is the ancestral species and which one is the evolved species.

The point of the Paradox is not to show that evolution does not take place, but rather that evolutionary biologists (i.e. all biologists) (i.e. all human beings other than fundamentalist crazies) cannot rid themselves of their own ingrained assumption that ancestors should be safely dead and currently existing species are necessarily 'modern' or at any rate the last in the line. Jasem now proceeds to demonstrate how necessary this corrective is.
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Mick Harper
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One of our most important principles is ‘careful ignoral’, in turn one of the most important ingredients of cognitive dissonance. Notice how Jasem, having been introduced to an important factor in all trunk and branch paradigms, strives might and main to avoid it.

Jasem Kashani
I didn't suggest lions and tigers were the same species, or that they had a living ancestor. You've become distracted by an example I used to counter a false assertion you made.

Actually, Jasem, it’s you that has been distracted. Why can’t lions and tigers have a living ancestor? There are plenty of cat species to choose from. Why can’t one be the ancestor of the other? But he returns to his first love

You asked for a living ancestor with an evolved species living along side. This is polar bears and brown bears which diverged from each other 150,000+ years ago. Of course they can mate, as can many bird species, and even plant species can cross breed - it's nothing special and does not change the fact that a polar bear and a brown bear are distinct creatures.

If you still disagree that either of these are different animals, or that the ability to mate across species somehow disqualifies a species from evolution - I give up!

Oh no, he hasn’t. He very incautiously tries to solve the Living Ancestor Paradox with an actual example!

As for Darwin's Finches: it was recently proven that 'Big Bird' Finches evolved from the Large Cactus Finches http://science.sciencemag.org/content/359/6372/224…

Time for Hatty to crush him. Time to see whether he will notice he has been crushed....
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Mick Harper
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Harriet Vered
You don't seem able to see that every example you've come up with is a case of cross-breeding between existing species including your finch example

"An immigrant Darwin’s finch to Daphne Major in the Galápagos archipelago initiated a new genetic lineage by breeding with a resident finch (Geospiza fortis)."

The whole point of neo-Darwinism is that the new species is created by genetic mutation, not cross-breeding. Jasem, there are several million species out there and you've just got to come up with a single example of an existing ancestor and its existing, evolved (by genetic mutation) species.

At this point, there was a period of silence and Hatty, who is at heart a kindly soul, was going to leave it there. M J Harper, who is not at heart a kindly soul, urged her to give him one last tweak

Harriet Vered
Have you thrown in the towel, Jasem? If it's any consolation, the greatest minds in evolutionary theory have also failed The Living Ancestor test. There just aren’t any to be found, though whether this undermines Darwinism is debatable. But what our exchange illustrates is that as soon as any doubt is raised, apologists for Darwin instantly go on the attack and rubbish the doubter, generally throwing insults around just as you started off saying I’m about as intelligent as a cockroach. You should perhaps examine your own stance more critically. But an apology will make all things right.

We had misjudged our man.

Jasem Kashani
Alas, no - I've just had a busy week & I'm just growing a little weary of the cyclical disagreement!

Oh no he wasn't. Not by a long chalk.
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Mick Harper
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Jasem Kashani
Just as you repeat your statement "you've just got to come up with a single example of an existing ancestor" - I will continue with polar bears & brown bears - this is an example of genetic mutation. We are at an impasse, it seems!

So...Polar bears are an example of genetic mutation with a living ancestor, and the finches are an example of cross breeding - to cover both points - both created new species. Both 'neo' and 'classical' Darwinism accounted for, with no coherent rebuttal as yet. Your only rebuttal seems to be polar bears didn't form from cross breeding, and that the finches (in question) didn't form from genetic mutation - which I agree, it is the opposite as I write above.

Jasem has quite forgotten that these are all his own examples as he has been driven from pillar to post. He started with dogs/wolves (not natural selection), then brown/white bears (not separate species), then lions/tigers (not ancestor-and-daughter), then finches (not mutation). But as far as he's concerned he's rounded every post in an obstacle race of Hatty's devising. Just for good measure he explains why he insults anti-Darwinists. It is to engender debate.

Whilst I'd agree my initial cockroach insult was crude, I also hope you note I start by throwing an insult out. Quite effective at eliciting a response I hope you'll agree!

I do indeed, Jasem. I'll be trying out the technique myself next time I get the chance.

Then, when confronted by coherent opposing views I debate at length - I become less barbarous and occasionally concede I'm wrong!

Yes, that's the second time you've mentioned this unusual trait. Though not employed on this occasion, I think.

I don't think we'd still be debating this if I was simply 'throwing insults'. I'll post my favourite Dawkins moment below - he's known himself to be a tad cutting with his words & views.

I have as yet heard no counter/alternative to the current theory of evolution from you; You ask for evidence and then dismiss valid exhibits; and you seem to disbelieve 'selection of the fittest' is a valid premise with no given reasons. I won't be apologising until we get to that point

As I say though, more than happy to concede when I'm wrong!

Third time. But I did like this

We learn more in failure than victory, after all ✌️

There was a bit more but we can leave it there. It was win-win!
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