Creationist and Kinds

[Policy]

You are correct. I was thinking about extant populations only which indeed is too simplistic, especially in light of extinct populations.

In my second definition, the problem is actually made clear: 2 populations that could interbreed and produce viable off spring, but don't (for whatever reason). These are on a path of inevitable diversion to the point where interbreeding will no longer produce viable off spring (or off spring at all). This is what occurs in ring species.

It's also what occurs in lineages. Every creature ever born was of the same species as its parents. But go back by skipping 100.000 generations and the ancestor you meet there... hardly the same species as the current extant descended.

A point I was thinking about adding to my post (and in retro-spect, I should have...) is that the concept of "species" really only makes sense as a "snapshot" of the "current state of life".

Species indeed is a very dynamic / fluid thing which is already hard enough to pin down for extant life only. It only gets more complex if we include extinct life also.


As a useful analogy, I really like the concept of "language" as the development / evolution of language follows the same gradual pattern. At what point did spanish became spanish? When did it stop being Latin? And if we would go to the middle of that evolution, what would we call that? Spatin?
Or take the extreme dialects of any language. At which point does it "stop" being the original language and when is it a new language?

In the netherlands, there is a great example of this. All the way in the north is Friesland.
Start in the south and work your way north. In the south, I understand every word they say: it's just dutch. The same language I speak (even though our dutch is called "flemish"... which imo is just an accent / dialect difference). The further north we go, the less I understand of it. By the time we get to Friesland, I literally do not understand a single word of it!

So where does it stop being "dutch"? I have no idea.


So in summary.... I stand corrected.
Although I think that for extant life, the two definitions I gave are very workable.

Interesting. Why do you think @Heyo is correct, and correct about what exactly? What ring species show us (as with your excellent Netherlands example is that neither species, nor languages are strictly discrete, but are a spectrum of overlapping (ahem) dna. That one might potentially be a member of multiple species if one's ability and normative behavior is to mate with both outside of one's aggregate alleles.

Now, if humans actually met Vulcans, and Minbari and Cylons, and all were both able to procreate and DTF, that would be interesting. But the fact of the matter is that here on Earth, we don't have that situation afaik.

BTW, I heard last month that the cycle time on a species is thought to be about 200 - 300k years. Which would make us a different species from the original sapiens sapiens. Or there abouts. I will see if I can scare up the reference.

 

[TagliatelliMonster]

Interesting. Why do you think @Heyo is correct, and correct about what exactly?

If the definition of "species" is dependent on the question "can they produce viable off spring?" then it is literally impossible to determine if fossils of extinct populations are of the same species or not.

So at least for extinct populations, there would have to be *other* variables to take into account - by necessity.

When I gave my 2 definitions, I simply wasn't thinking of extinct population, only extant ones.
And in that context, I think my definitions are just fine. But for obvious reasons they aren't workable for extinct life. Something else is needed.

What ring species show us (as with your excellent Netherlands example is that neither species, nor languages are strictly discrete, but are a spectrum of overlapping (ahem) dna. That one might potentially be a member of multiple species if one's ability and normative behavior is to mate with both outside of one's aggregate alleles.

Yeah. Which just goes to show that it is near impossible to pin species down in neatly separated boxes. There is indeed an overlap and at some point, one will have to make arbitrary distinctions.
That - or we use multiple definitions of the concept of "species" and apply the definition that makes most sense in the context we are dealing with.

Where it might make sense to define it one way in a certain context, it might make more sense to define it slightly differently in another.

 

[Policy]

If the definition of "species" is dependent on the question "can they produce viable off spring?" then it is literally impossible to determine if fossils of extinct populations are of the same species or not.

Sure. If dogs and wolves and foxes had lived 65 million years ago, we probably could not have told which ones could interbreed. I am not sure if we could have determined that dogs were all of one species either. But I would be really really interested to fine out if a phenomenon like dogs can occur under unintelligently designed pressures. Simeone must have done a study on that by now!

So at least for extinct populations, there would have to be *other* variables to take into account - by necessity.

Hmmm. Maybe. I think that we are fine defining a species as being both willing and able. What we have to question is whether we can look at a group of fossils and determine if we are looking at one species or two, or three. I doubt that we always could, but I can think of ways that we could make a reasonable falsifiable hypothesis for any given situation based on range and morphology. Assuming a large enough sample set.

There is a difference between what a species is, and whether we can determine that a given fossil group is a single species.

 

[Audie]

I don't think that's entirely accurate though.

When a paleontologist studies 2 different fossils and concludes that the fossil individuals are from the same species, I'ld think that that paleontologist is of the opinion that those two would be able to breed and produce viable off spring.

You gave the example of neanderthals and homo sapiens. A good example though.
But it raises the question.... are they truly "different species"?

The question could be asked... if 100.000 years from now, a paleontologist finds the fossil remains of 2 radically different breeds of dogs, would he consider it different species? Assuming no access to genetics or records about ability to breed etc... my guess is that yes: they would classify it as different species.
But they are not today. They are called "breeds", but the same species.

Maybe the same should be true for Neanderthals and sapiens.


It's a fascinating subject and I think the bottom line is that in the end, it's all rather arbitrary. We are trying to classify things into neatly separate boxes, while in reality these things are all very gradually interrelated and very fluid.

The thing is that, especially when we look at it from a historical lineage point of view, it's near impossible to tell where one species ends and another begins.

100,000 yrs or 100,000,000 the answer is still
no.

The the 20th century maker in the geological
column will be the most exact and obvious one
for any time in earth history, unless 21st, 22nd do even more dramatic stuff.

The dogs show up along with people.
Also, no two organisms can succeed in filling the same niche- and ftm, most dogs are bred to be utterly unfit to survive independently.
Wild weiner dogs, no way.

 

[TagliatelliMonster]

100,000 yrs or 100,000,000 the answer is still
no.

The the 20th century maker in the geological
column will be the most exact and obvious one
for any time in earth history, unless 21st, 22nd do even more dramatic stuff.

The dogs show up along with people.
Also, no two organisms can succeed in filling the same niche- and ftm, most dogs are bred to be utterly unfit to survive independently.
Wild weiner dogs, no way.

You assume they'ld know what we know today.

Imagine they are completely clueless about our day and age and all they have to work with is a fossil chiwawa found in Spain and a fossil st bernard found high up in the Alps.

On what criteria would they think they are the same species?

 

[Audie]

You assume they'ld know what we know today.

Imagine they are completely clueless about our day and age and all they have to work with is a fossil chiwawa found in Spain and a fossil st bernard found high up in the Alps.

On what criteria would they think they are the same species?

" Chihuahua". : D

It would depend, as knowledge always does, on
the completeness of data.

But they effect of humanity around out current era would be very obvious, as would the association of dog, chicken, cow, pig bones,
many of them with saw.

Since we dont know as how its human beings doing paleo 200,000,000 yrs from now we wont be able to predict how thorough they might be, or how they define species.

 

[9-10ths_Penguin]

I think we should put that question to rest until we have a (single) definition of "species".

Why would that be reasonable?

I mean, evolution implies that the boundaries between species are going to be... fuzzy. When we know that species will go through speciation, we know that we'll find examples in the world that don't fit any clean definition of "species" (e.g. ring species).

The creationists, though... they don't have this problem. They claim that the "kind" is a distinct unit: evolution can happen within "kinds," but can't make an organism change "kinds." With this supoosedly firm division between "kinds," they really ought to be able to say where those firm divisions are.

 

[Audie]

Why would that be reasonable?

I mean, evolution implies that the boundaries between species are going to be... fuzzy. When we know that species will go through speciation, we know that we'll find examples in the world that don't fit any clean definition of "species" (e.g. ring species).

The creationists, though... they don't have this problem. They claim that the "kind" is a distinct unit: evolution can happen within "kinds," but can't make an organism change "kinds." With this supoosedly firm division between "kinds," they really ought to be able to say where those firm divisions are.

As in, no such definition is possible,
any more than three's an exact line
between night and day

 

[Heyo]

Why would that be reasonable?

I mean, evolution implies that the boundaries between species are going to be... fuzzy. When we know that species will go through speciation, we know that we'll find examples in the world that don't fit any clean definition of "species" (e.g. ring species).

Exactly. We don't have a clear definition, we shouldn't demand one from them. It's not a hill I want to die on.

 

[9-10ths_Penguin]

Exactly. We don't have a clear definition, we shouldn't demand one from them. It's not a hill I want to die on.

We can't clearly divide life into distinct slices because it isn't distinct in reality; life is a continuum. In an evolutionary paradigm, any slicing of the diversity of life into discrete chunks is going to be arbitrary to an extent.

OTOH, the creationists are arguing that life is not a continuum and that there are real, empirical divisions in the diversity of life. It's perfectly reasonable to ask them where those divisions are.

 

[Heyo]

We can't clearly divide life into distinct slices because it isn't distinct in reality; life is a continuum. In an evolutionary paradigm, any slicing of the diversity of life into discrete chunks is going to be arbitrary to an extent.

OTOH, the creationists are arguing that life is not a continuum and that there are real, empirical divisions in the diversity of life. It's perfectly reasonable to ask them where those divisions are.

It pretty much depends on where you are in a discussion. When it comes to the point, I usually ask what the mechanism is that prevents certain mutations - and, yes, sometimes I also ask where the boundaries are. But most of the time I ignore the "kind" topic.

 

[Subduction Zone]

Hmm, odd. No definition of "kind" by creationists yet. Well I am certain that it will happen almost any post now.


The fact that there is no clear definition of a species in biology is due to the fact of evolution. In other words it is a feature not a bug. Due to how life evolves and the fuzzy nature of being able to interbreed there are no sharp hard lines in the sand between species in evolution. That we cannot come up with a solid definition is to be expected.

The opposite is true for creationism. If their belief is correct then they should be able to find a way to show how any two groups of animals could be shown to be of the "same kind" or not. One only has to point to the vast array of dogs to show that it has to go beyond mere looks.

 

[9-10ths_Penguin]

It pretty much depends on where you are in a discussion. When it comes to the point, I usually ask what the mechanism is that prevents certain mutations - and, yes, sometimes I also ask where the boundaries are. But most of the time I ignore the "kind" topic.

Seems like those are two ways of asking a very similar question: asking what a "kind" is and asking where the boundaries are between kinds are just rephrasings of each other.

 

[GardenLady]

I recommend using Borges' classification system:

In The Analytical Language of John Wilkins, Borges describes 'a certain Chinese Encyclopedia,' the Celestial Emporium of Benevolent Knowledge, in which it is written that animals are divided into:

1. those that belong to the Emperor,
2. embalmed ones,
3. those that are trained,
4. suckling pigs,
5. mermaids,
6. fabulous ones,
7. stray dogs,
8. those included in the present classification,
9. those that tremble as if they were mad,
10. innumerable ones,
11. those drawn with a very fine camelhair brush,
12. others,
13. those that have just broken a flower vase,
14. those that from a long way off look like flies.

Please define the difference between #5 and #6.

 

[GardenLady]

Are Humans and Neanderthals?

Since I am a Homo Sapiens Sapiens and also have the DNA of Neanderthals (2.4%) Denisovans (2.5%)--this per the National Geographic Society's Genographic Study-- I'm going to to say "Yes."

 

[Kooky]

Please define the difference between #5 and #6.

Mermaids are clearly not fabulous enough to qualify for #6, although mermen might be.

 

[Yazata]

Creationists - what is the definition of a kind?

A kind is a generalization in which a collection of individuals is grouped into classificatory categories based on shared traits. Typically, natural kind terms are what scientific theories address: 'silicate', 'gas', prokaryote', 'star', 'lepton'...

These are all 'kinds' in the sense that they are general taxonomic categories into which an undetermined number of particular individuals belong based on their possessing chosen properties in common. What makes them 'natural' is that it's believed that the categories exist objectively and independently of our choosing to group them that way. Rather, we are recognizing basic similarities that actually exist in nature.

Natural Kinds | Internet Encyclopedia of Philosophy

STOP!

I did not ask for examples. I asked for a definition. What are the complete list of criteria that I can use to determine if any two random animals are of the same kind/

If natural kinds exist objectively in nature, in the way that we assume that the fundamental particles of physics or the chemical elements do, then these taxonomic categories are going to be arrived at by description, not by a-priori definition. They are discovered, not prescribed.

What's more, one of the more popular philosophical accounts of natural kinds is known as "cluster theory" (described in the encyclopedia article above). This one is particularly popular among philosophers of biology. It interprets individuals as collections of properties. Then it questions whether there is any necessary and sufficient set of "essential" properties that establish an individual as a member of a particular 'kind'. So in this account, membership in a 'kind' becomes a matter of family resemblance. And that family resemblance can arguably be explained causally, by the history of biological lineages, by natural selection etc.

And that would seemingly have to be approached descriptively by examining examples, rather than a-priori.

 

[Policy]

A kind is a generalization in which a collection of individuals is grouped into classificatory categories based on shared traits. Typically, natural kind terms are what scientific theories address: 'silicate', 'gas', prokaryote', 'star', 'lepton'...

These are all 'kinds' in the sense that they are general taxonomic categories into which an undetermined number of particular individuals belong based on their possessing chosen properties in common. What makes them 'natural' is that it's believed that the categories exist objectively and independently of our choosing to group them that way. Rather, we are recognizing basic similarities that actually exist in nature.

This is not a definition of 'kind' . It is a categorization of 'kind' and a partial definition of taxonomy.

If natural kinds exist objectively in nature, in the way that we assume that the fundamental particles of physics or the chemical elements do, then these taxonomic categories are going to be arrived at by description, not by a-priori definition. They are discovered, not prescribed.

I assume that you mean if individuals that full under the one of the kind categories exist objectively in nature. Taxonomic nomenclatures are not objective entities.

I don't agree. The characteristics of individual entries are discovered, not defined. However, the categories that we create are defined.

 

[Fallen Prophet]

Creationists - what is the definition of a kind?

STOP!

I did not ask for examples. I asked for a definition. What are the complete list of criteria that I can use to determine if any two random animals are of the same kind/

I would assume - based on the subject matter of the text - that the word "kind" would refer to those creations that could mate with each other or otherwise reproduce.

"And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it was good." (Genesis 1:12)

"And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good.

And God blessed them, saying, Be fruitful, and multiply, and fill the waters in the seas, and let fowl multiply in the earth.

And the evening and the morning were the fifth day.

¶ And God said, Let the earth bring forth the living creature after his kind, cattle, and creeping thing, and beast of the earth after his kind: and it was so.

And God made the beast of the earth after his kind, and cattle after their kind, and every thing that creepeth upon the earth after his kind: and God saw that it was good." (Genesis 1:21-25)

 

[Policy]

I would assume - based on the subject matter of the text - that the word "kind" would refer to those creations that could mate with each other or otherwise reproduce.

"And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it was good." (Genesis 1:12)

"And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good.

And God blessed them, saying, Be fruitful, and multiply, and fill the waters in the seas, and let fowl multiply in the earth.

And the evening and the morning were the fifth day.

¶ And God said, Let the earth bring forth the living creature after his kind, cattle, and creeping thing, and beast of the earth after his kind: and it was so.

And God made the beast of the earth after his kind, and cattle after their kind, and every thing that creepeth upon the earth after his kind: and God saw that it was good." (Genesis 1:21-25)

Creationists do not use it that way unless it is convenient to do so. For instance, they claim that there is a "cat kind" even though the assorted species of cats are not all cross fertile.