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Author Topic:   All species are transitional
SuperNintendo Chalmers
Member (Idle past 5834 days)
Posts: 772
From: Bartlett, IL, USA
Joined: 12-27-2005


Message 238 of 246 (274191)
12-30-2005 12:42 PM
Reply to: Message 1 by Parasomnium
10-04-2005 9:48 AM


What we need to realise is that we are trying to impose an arbitrary system of discrete divisions on a continuous set of elements. With species it is no different. If you translate the example of the numbers to species, you can imagine a continuous sequence of intermediates from any ancestor you'd care to start with, right up to yourself. You are the same species as your parents, and they the same as theirs. At the other end of the line, the ancestor you started with is the same species as its offspring, and they are the same species as their offspring.
But if you went back far enough in the lineage so that the ancestor you start with is a tree-dwelling primate, then obviously this ancestor is not the same species as you. There must be transitionals. But wherever you look in the lineage, locally you cannot pinpoint any real transitions. That's because the transition takes place all over the lineage. Each and every one of your ancestors is a transitional. And if you have children or plan on having them, you are a transitional yourself.
Great, Great post. I think the problem is what we are really talking about are population groups. All members of a population group (at least for sexually reproducing animals) are always of the same species. There is no such thing as species A giving birth to species B. There are only population groups which change over time and may also split up. So a population group is always the same species... and in fact, like Para said, Species is a just an arbitrary classification we use when looking back over time at various population groups.
I liked to use the analogy of the aging process (not perfect, but I think it illustrates a good point). There is never a point in your life when you wake up and say, "wow yesterday I was a child and now I am an adolescent". However, when you look back at your life you do say, "X happened when I was a child" and "Y happened when I was an adolescent". However, in reality every single instant of your life is a different step in the aging process.
I've heard many people bring up the example of dogs and how they have never speciated even though we've been breeding them for thousands of years. Do we actually know this (I really don't know the answer here)? How do we know that present day dogs could breed with dogs that lived 15 or 20 thousand years ago? They may very well be a different species using that definition

This message is a reply to:
 Message 1 by Parasomnium, posted 10-04-2005 9:48 AM Parasomnium has not replied

Replies to this message:
 Message 239 by Faith, posted 12-30-2005 12:56 PM SuperNintendo Chalmers has replied

  
SuperNintendo Chalmers
Member (Idle past 5834 days)
Posts: 772
From: Bartlett, IL, USA
Joined: 12-27-2005


Message 242 of 246 (274203)
12-30-2005 1:35 PM
Reply to: Message 239 by Faith
12-30-2005 12:56 PM


The problem with this whole idea is that whenever you split a population group, each new group, while developing new forms, loses some genetic potentials, so the idea that there can be continuous open-ended change is an illusion. Over time the processes that split populations {ABE: and produce new phenotypes} also reduce genetic diversity, which ultimately reaches a point where no further change is possible. It sounds good but it doesn't work. I believe this natural limit to change is the definition of a Kind. Yes, supposedly mutation counteracts this effect, but I think that's mostly a matter of blind faith too.
There is absolutely no evidence to support this that I am aware of...
What "genectic potentials" are even required? I've never even heard of that term (although I'm no biologist).
If understand how all this works... Doesn't every single act of sexual reproduction contribute to genetic diversity? Combining this with mutation seems to be more than adequate for evolution.
I don't understand what you are talking about. You seem to think there is some level of genetic diversity require somehow... what level is that? Can you quantify it? Or did you just make this up?
(I just googled this and couldn't find anything about it)...
How small does a population group have to be before it can't cant any more...
This sounds like wild hypothesizing with no evidence to me....

This message is a reply to:
 Message 239 by Faith, posted 12-30-2005 12:56 PM Faith has not replied

Replies to this message:
 Message 243 by Adminnemooseus, posted 12-30-2005 1:43 PM SuperNintendo Chalmers has not replied
 Message 246 by Brad McFall, posted 12-30-2005 11:06 PM SuperNintendo Chalmers has not replied

  
SuperNintendo Chalmers
Member (Idle past 5834 days)
Posts: 772
From: Bartlett, IL, USA
Joined: 12-27-2005


Message 245 of 246 (274272)
12-30-2005 7:28 PM


population groups
So to get back on topic... Along with all species being transitional species is a completely human concept. It's simply a classification system like any other (middle-aged vs elderly people, etc).
Another important point is that all members of a population group (for sexual reproducing creatures) are always in the same species. In fact, evolution predicts that it should be almost impossible to witness live speciation except for very short-lived creatures.
So not only is the argument "Show me a cat turn into a dog" not hold water it would actually be evidence against the theory of evolution if it was true.

  
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