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Author Topic:   Ring species
DBlevins
Member (Idle past 1916 days)
Posts: 652
From: Puyallup, WA.
Joined: 02-04-2003


Message 11 of 22 (619322)
06-09-2011 1:29 PM
Reply to: Message 9 by New Cat's Eye
06-09-2011 11:58 AM


Is an 'Ape' a 'kind'...
No, "ape" would be too broad to be a kind. A human is a differnt kind than a chimp.

Chimpanzee's are classified in the Hominidae Family along with Gorillas and Orangutans and...Humans. We ARE part of the classification known as the "Great Apes".

As far as comparing Humans with Chimpanzees, we share about 96% of our genes with them, so I have to wonder what degree of difference you would consider for being a 'kind'. (of course that topic has been brought up many times here...)


This message is a reply to:
 Message 9 by New Cat's Eye, posted 06-09-2011 11:58 AM New Cat's Eye has responded

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 Message 12 by frako, posted 06-09-2011 1:47 PM DBlevins has not yet responded
 Message 13 by New Cat's Eye, posted 06-09-2011 2:28 PM DBlevins has responded

  
DBlevins
Member (Idle past 1916 days)
Posts: 652
From: Puyallup, WA.
Joined: 02-04-2003


Message 14 of 22 (619353)
06-09-2011 3:13 PM
Reply to: Message 13 by New Cat's Eye
06-09-2011 2:28 PM


Re: Is an 'Ape' a 'kind'...
...I don't see any reason to force the evolutionary classifaction system into the definition of kind.

I'm not forcing an evolutionary classification on to the definition of kinds. I am trying to understand what you mean by the definition of 'kind'.

Too, we know that humans and chimps must be different kinds so an evolutionary classification like Hominidae isn't going to work as a kind either.

How do we know they are different kinds if we don't have a definition of what constitutes a 'kind'?

Who is "we"?

In the end, I think it does depend on how much micro-evolution is capable. With a lot of it, we could maybe trim down the ant kinds into just 2 of them, the large ants and the small ants (or whatever), that have diverged into all the different types of ant we see today.

On the other hand, if not very much micro-evolution is possible, then a lot of those different types of ants would all be their own kinds.

Are you confusing the mount of genetic change that has taken place with the degree of genetic change possible?

What limits the amount of micro-evolution possible?


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 Message 13 by New Cat's Eye, posted 06-09-2011 2:28 PM New Cat's Eye has responded

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DBlevins
Member (Idle past 1916 days)
Posts: 652
From: Puyallup, WA.
Joined: 02-04-2003


Message 18 of 22 (619391)
06-09-2011 4:27 PM
Reply to: Message 15 by New Cat's Eye
06-09-2011 3:43 PM


Re: Is an 'Ape' a 'kind'...
It looked to me like you were expecting some sort of parallel to the evolutionary biological classification.

Nope. Just looking for a clear definition of what constitutes a "kind".

Well, one way is if they aren't capable of reproducing, then they cannot be the same kind. (but the contrapositive isn't necessarily true).

Then we have examples of salamanders Ensatina eschscholtzii, fly's, birds Greenish Warbler, etc of not being able to reproduce even though they look remarkably similar to each other. But that just obscures the big idea, that being unable to reproduce seperates kinds. If that is the case, then there would be 1000's of kinds even among the birds.

Like I said, though, its going to depend on how much micro-evolution is possible. If it isn't possible for the two types to have evolved from a common ancestor, then they must be different kinds.

What do you mean when you say, "...how much micro-evolution is possible"? You appear to be saying that there is some arbitrary limit to micro-evolution. If so, what is that limitation?

You're traveling dangerously close to the Theory of Evolution when you say, "If it isn't possible for the two types to have evolved from a common ancestor, then they must be different kinds". Common ancestry is a central pillar of the ToE. ie. We share a common ancestor with the chimpanzees.

If we share common ancestry with the chimpanzees, then we are of the same kind?

The proverbial we... the royal we.

Cute. I wasn't aware you were royalty. Is there anyone else who, "...know[s] that humans and chimps must be different kinds..."? Are you the only one that "knows" chimpanzees must be different kinds?

Obviously though, if an amount of genetic change is impossible then it couldn't have taken place.

How do you determine how much genetic change is impossible? You seem to suggest that nature does, but it is clear from the fossil record that speciation is still going on even after 100's of millions of years.


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 Message 15 by New Cat's Eye, posted 06-09-2011 3:43 PM New Cat's Eye has responded

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 Message 19 by New Cat's Eye, posted 06-09-2011 4:39 PM DBlevins has responded

  
DBlevins
Member (Idle past 1916 days)
Posts: 652
From: Puyallup, WA.
Joined: 02-04-2003


Message 20 of 22 (619421)
06-09-2011 6:09 PM
Reply to: Message 19 by New Cat's Eye
06-09-2011 4:39 PM


Re: Is an 'Ape' a 'kind'...
Has there been studies on whether or not those warblers are capable of reproduction but simply do not?

You might want to take the time to read this from Darren Irwin's website.

As far as determining the ability to reproduce of ring species, there have been other studies as well that show ring species who's hybridization attempts were unsuccessful or had low viability rates.

In any case, the point is that small genetic changes accumulate until there is a point when the species splits and form a distinct and seperate species. The papaer I site above goes into the species concept and possible alternatives to the allopatric species concept.

Under creationism, there has to be some limit to how much micro-evolution can happen in order for there to be disctinct kinds that could not have evolved from each other. I don't know enough about it to say exactly what that limitation is, but I'd guess it have something to do with accumulating enough deleterious mutations to halt reporduction. Heh, although that probably won't make sense because if they're deleterious then we wouldn't expect them to be passed on and build up.

Species that are genetically isolated from each other but share a recent common ancestor, such as ring species, are reproductively viable among their respective groups. If such was the case that deleterious genes built up then we would expect that reproductive viability would decline. ie We would expect to see a statistically significant amount of dead/mutated birds as we move along to different hybridization zones and not viable communities.

To take things further, we would expect that as evolution progressed, we would not see new groups develop because of the tremendous amount of deleterious genes that were built up during speciation. Unless you think it is a much slower process than that? Of course that would be a problem if you believed in Creationism, because that would still allow for evolution to have taken place.

me writes:

How do you determine how much genetic change is impossible?

CS writes:

I dunno. You could probably determine a max amount given a certain amount of time. Don't you think there's got to be some upper limit on a mutation rate?

If, such as in my case, I understand that the Earth has had living organisms for 100's of millions of years, then I don't see a limit to the accumulation of mutations other than the viability of the earth to sustain life. Why could you not allow for a SLOW rate of change over a very LONG time? If, over a long time, the genetic change continues then more mutations will be evident and what was once a homogenous groups will split and become a new group. If my group is reproductively isolated from the parent group, for whatever reason, for 10's of million's of years, what do you think will happen?


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