All species are transitional

It's harder to explain to a creationist. The gradualness and arbitrary nature of labelling something a species is much less obvious then if you use a different definition.

Thinking in terms of "kinds," is, I think, the major stumbling block, apart from sheer bias, in understanding TOE. It's also very natural. A cat's a cat, a dog's a dog. So from a political standpoint, so to speak, it would be better to speak of species in terms of physical differences.

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"Turning out pigs for creationists makes me blue and blurry."--Brad McFall

I'm impressed by your high-tech graphics. I wish I could do stuff like that. I was speaking of it working in a "political" sense. Well, I thought it summed up my own point of view rather cogently.Brad has the makings of a poet--in the Modernist style, circa 1930.This message has been edited by robinrohan, 10-21-2005 08:30 PMThis message has been edited by robinrohan, 10-21-2005 08:35 PM

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"Turning out pigs for creationists makes me blue and blurry."--Brad McFall

That is not Parasomnium's face. Parasomnium is this old guy in khakies. He lives in Belgium. His native language is Dutch, kind of like German. He's interested in memes. His country is moving right, due to immigration, which is upsetting. He's not real fond of his Prime Minister. God help you if you are a dualist. Parasomnium will not put up with that.That's all I know about Parasomnium.

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"Turning out pigs for creationists makes me blue and blurry."--Brad McFall

"I grow old. I grow old.
I shall wear the bottoms of my trousers rolled.Do I part my hair behind?
Do I dare to eat a peach?
I shall wear white flannel trousers,
And walk along the beach."

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"Turning out pigs for creationists makes me blue and blurry."--Brad McFall

Wonderful!

If you wanted to explain the problem of someone thinking in terms of "kinds"--which is a "natural" way to think--it's much easier to explain it to them by defining "species" in terms of changes in the body of a life form rather than "gene pool isolation."Let's think about fossils. Now here all we have are snapshots of what a life form looks like. There is no data about gene pool isolation, I assume, except in some rare case. Say we had 40 fossils along an evolutionary branch. Fossil #1 is the oldest and fossil #40 the most recent. They all look a little different. It's easy for someone to realize that we could label fossil #24 or #25 or #26 as a new species if we wanted to or, if we wanted to, we could call them all different species. This shows us that "macroevolution" is a meaningless term.So by "political," I mean pedagogical, with the understanding that this whole issue has political implications. Sometimes a teacher has to simplify.The layman (such as myself) tends to think in terms of fossils when he considers the evidence for TOE.It's less easy--as it was less easy for me--to visualize the point of "gene pool isolation" as something gradual and, above all, as something arbitrary. In fact, "arbitrary" seems to be the wrong word in this context, but it seems just the right word using the other definition.This message has been edited by robinrohan, 10-25-2005 02:48 PM

I think is much easier to understand that a decision between "natural variation" and "different species" is a mere matter of labelling. It has the advantage of not being an analogy. This other evidence is vague to most people. Something about DNA.The graphic showed me the gradual nature of gene pool isolation. I'm still a little shaky about it but I grasped it well enough, I think. Here's the way I understand it: You've got group A (wolves) and later on you've got two other groups (dane and chihuahua). During this period of change some of the proto-danes and some of the proto-chihuahuas continued to interbreed and some couldn't. Eventually it got to the point where none of them could. If we are speaking of individuals, either you can interbreed or you can't. If we are speaking of the entire group, then we can speak of a gradual process of isolation and therefore of "semi-isolation." That's the "intermediate" that I was looking for.This message has been edited by robinrohan, 10-25-2005 04:21 PM

Here's the problem: I was thinking that "arbitrary" meant we might say that a variation is a new species or we might not. It's just a label. But gene pool isolation is not arbitrary. We can't say that we can call two groups isolated, or maybe we can call them non-isolated.They either are isolated or they are not. We can say that some of the group are isolated and some not, and call that semi-isolation, and thus gradualness of isolation can be seen to take place. But whenever all of them are isolated, then we are not applying an arbitrary label by calling them a different species.This message has been edited by robinrohan, 10-25-2005 04:37 PM

There's a group of 50 black furry creatures living in the woods. One day, one of these creatures gives birth to one that has some yellowish speckles on its coat. It turns out that this slightly speckled coat has the effect of camouflage in the bushes. This speckled creature thrives and mates with an un-speckled creature. Several of the litter are speckled. They also thrive and mate. Eventually through some more generations, a speckled creature mates with another speckled creature, and the result is offspring that are even more speckled. When this heavily speckled creatue meets an un-speckled creature, they do not recognize each other as potential mates. So this heavily speckled creature must mate with another speckled creature. This trend continues.Is there a particular point in time, a particular generation, which we can say is a new species, using the definition of isolated gene pool?Generation #1--one slightly speckled creature
Generation #2--3 slightly speckled out of a litter of 6
#3--5 slight spleckled
#10--20 slightly speckled
#11--2 heavily speckled
#18--15 heavily speckledThis message has been edited by robinrohan, 10-26-2005 01:27 PM

So it's valid to say that that first heavily speckled creature--the first one ever--is a new species when he is born?ABE: that would be one species giving birth to another species.This message has been edited by robinrohan, 10-26-2005 08:17 PM

It's not about "liking it to be," old buddy--it's about figuring it out. And I am determined, in my simple-minded way, to figure it out. Your rain analogy was pretty good.But what I want to know is--if one could go back in time--if one could identify a particular species being born from another species at a particular time.The way I figure it is, it depends on what definition of "species" one adopts. Now this is all very difficult. What I want it to be is arbitrary. We could call the heavily-speckled creatures a different species if we wanted to, but we could also call them a variant. However, if we adopt the definition suggested by Parasomnium, I'm not sure we could call them a variant.

But doesn't it begin with one?

I'm talking about a successful species. Take our 50 creatures in the woods. Doesn't it begin with one? I think it unlikely that 2 creatures would be born, due to mutation, with some speckles. Over time the speckled creatures mated and produced a heavily speckled creature. At this point, a new species was produced because it could not recognize a non-speckled creature as a mate. The new species occurred when the heavily-speckled creature was produced. If one had a time machine, one could date it to a certain day, given the definition of species adopted by some---"gene pool isolation."However, if one adopts the definition of morphological change, then one can name one's new species whenever one likes.

And your point, Nosy?