On the thread entitled “Species Kinds”, commenter phoodoo asks:
What’s the definition of a species?
A simple question but hard to answer. Talking of populations of interbreeding individuals immediately creates problems when looking at asexual organisms, especially the prokaryotes: bacteria and archaea. How to delineate a species temporally is also problematic. Allan Miller links to an excellent basic resource on defining a species and the Wikipedia entry does not shy away from the difficulties.
In case phoodoo thought his question was being ignored, I thought I’d open this thread to allow discussion without derailing the thread on “kinds”.
Allan & Rumraket,
I disagree: colewd’s
is NOT circular. Like Sal’s
they are (as written) both tautologies of the form
A, therefore B
B, because A.
They’ve inverted both the conjunction and the word order. For circularity, they must only invert one.
L.B: “The unfashionable side…However, that could easily be altered.”
Jack: “Do you mean the fashion, or the side?”
L.B. “Both, if necessary.”
As a concept, it is an attempt categorize. Humans, for whatever strange reason, are obsessed with pigeon-holing everything and assigning labels to them. Have you rented a car lately? You get to select between sub-compacts, compacts, intermediates, etc. When I was younger there was only compacts and full size. Cars like the Toyota Corollas were compacts. Now they are intermediates.
Species are just a convenience for allowing discussion. Do you really think that a wolf and a German Shepard care about the fact that we classify them as different species?
And the species concept only works moderately well with animals. With plants, bacteria, etc. the concept fails miserably.
“Because circular reasoning isn’t what you think it is, so that proves you it.”
Very true. Dishonest? Stupid? In Sal’s case I would say the former… Cole, probably both
I wonder if Flint and the other skeptics know that little piece of “skeptical” received wisdom ?
By the way, the only reason the you think the concept fails is that you are locked into the strange presupposition that the delineation and boundary of a species is defined by reproductive isolation.
I wonder where you got that idea?
quote:
In biology and other natural sciences, essentialism provided the basis for and rationale of taxonomy at least until the time of Charles Darwin;the precise role and importance of essentialism in biology is still a matter of debate.
end quote:
from here
https://en.wikipedia.org/wiki/Essentialism
peace
We don’t, actually. They are both classified as different subspecies of Canis lupus, which just serves to further bolster your point about our need to categorize things.
Then I admit I still don’t get your point. If two individuals differ, is it their difference that’s “not genuine” or is it their similarity that’s “not genuine”? Two individuals are of the same species if they are similar enough for some purpose. So is it that purpose that’s “not geuine”?
I agree with Acartia here, the concept of a species is a useful concept, but this doesn’t mean it’s necessarily precisely defined. What people do is they come up with words to describe something, and then they demand precise and complete definitions of words even though the something being described is not itself clearly bounded.
You seem to have fallen into this same trap – that the WORD must have an exact definition even if what that word refers to is not itself exact or clear. And then you seem to think that if the WORD is exact, what it describes must be as well. If the reality being described is hazy, then reality must be at fault! You have made a category error.
First, we aren’t really talking about UCD per se, which is just the claim that all life is a single clade. We mostly focus on groups that are less than the totality of life. Better if we refer to common descent of those species included in some analysis. Mammals, say, or primates, or some genus of skink.
So let me rephrase as the logical connection between speciation and phylogenetic trees. There the connection is simple. If we see different species today, and we can determine that those species are related by descent, then by definition speciation must have happened at least once for each branching spot on the tree. The tree is evidence that speciation happens. There’s your connection. Was that circular?
Perhaps Flint and others have spent the time and made the effort to LEARN about such things, enough to understand what’s going on.
How so? In the first place, the concept does NOT fail, and is quite useful and descriptive among people who know what they’re talking about. And in the second place, reproductive isolation is not required. If two populations rarely interbreed, they can usefully be regarded as separate species EVEN IF there is the rare occasion of interbreeding, and EVEN IF the offspring of such a mating is fertile.
What do YOU think this quote is trying to tell you? Do you think other people here are being not essentialist enough? Or too much? Or what?
Of course it is. But I’m curious…what part of it makes you think otherwise? What is it you think “speciation” is or should be?
That’s kind of laughably naive, but whatever…
Here, this is a really good start:
http://www.scientificamerican.com/article/universal-common-ancestor/
Read it. Really read it . I’d suggest following up with the references for details on the comments provided in the article as well.
I did not claim the concept failed that was Acartia.
Do you think he likes being told he does not know what he is talking about?
It’s not about me.
I have no problem whatsoever with the notion of species.
It’s those from your side of the fence who can’t decide if it is a failed concept or one that is quite useful if you know what you are talking about.
As soon as you all get it ironed out we can compare notes.
😉
peace
He said it was a failed concept that is the result of human’s obsession with categorization. That is pretty much the opposite of useful is it not?
peace
It’s not “false” (your ridiculous presuppositional dichotomizing bias is showing here again), but it is artificial. It’s just a term humans use to separate two groups into two separate cognitive boxes. But it’s a relative term that some items don’t fit neatly under. It’s no more “true” in any absolute sense than a term like “hot” or “big”.
Because rational people can use the concept to use as a basis of comparison and refine understanding. Irrational people, otoh, try to hold it up as some ridiculous absolute and thus end up inventing myths and superstitions to hold their world together. But I digress…
FMM: “Do you think he likes being told he does not know what he is talking about?”
It wouldn’t be the first time. I have gotten used to it.
“He said it was a failed concept that is the result of humans obsession with categorization. That is pretty much the opposite of useful is it not?”
No, I said that it fails with plants and bacteria.
E. coli and E. coli 0157:H7 are different strains of the same species of bacteria. All warm blooded animals have millions of one strain in their gut and show no ill effects. A win-win for all. The other will kill you.
I think somehow you got the idea that the boundaries of a species are defined by reproductive isolation except when they are not.
I think that strange presumption has led to all sorts of muddled thinking.
I like to see some evidence that a species is a group of similar individuals capable of exchanging genes or interbreeding.
peace
You know, if you’re going to be disingenuous with regard to what people write, you should leave that silly “peace” off the end of your posts. It really gives the impression that you and your beliefs are just hypocritically vile. But hey…that’s just me…
For the record, Acardia did not say species is a failed concept; he noted quite specifically the conditions under which the term “fails miserably.” But, you knew that…and you don’t care. And yet, you insist you follow some moral standard. Either your god is a total punk or…well…I think your words speak for themselves.
artificial but “quite useful and descriptive for those who know what they are talking about”?
Is that like a good lie? 😉
peace
actually he said:
quote:
As a concept, it is an attempt to categorize. Humans, for whatever strange reason, are obsessed with pigeon-holing everything and assigning labels to them.
and
Species are just a convenience for allowing discussion.
and
And the species concept only works moderately well with animals. With plants, bacteria, etc. the concept fails miserably.
end quote:
It does not sound like he is a big fan of the species concept to me 😉
That has to be some sort of record for the shortest time before an attempt to poison the well to avoid the subject that I have seen here.
peace
I don’t think he was saying what you think he was saying. As I read it, he was saying that the human propensity to pigeonhole and demand precise fixed definitions makes the concept of species difficult for some people. The concept is useful, the need to force the concept to fit a highly specific definition when the reality does not, is not useful.
That’s not the way I see it, so I can’t help you there. Reproductive isolation is one avenue to speciation.
Seems to me you’re having difficulty reading then. Perhaps that would have something to do with your misunderstandings regarding the bible as well…
No…you just have a distinct history with regard to “misreading” others’ words.
It sounds to me like he is not a big fan of dishonestly pretending the concept works where it does not apply, nor is he a big fan of deliberately misunderstanding the term so as to mock those who know what it’s for.
Your comment sounds like someone saying a carpenter is not a big fan of hammers if he says they’re lousy for tightening screws.
That is certainly quite a lot of background to read into a simple statement.
Is there a reason you think he is unable to articulate his secret love for the concept of species an instead feels compelled to seemingly denigrate the whole notion in public?
I suppose I could take your comment to actually mean that you think that the concept of species is a mere human convention if you don’t demand precise fixed definitions .
It’s hard to tell what is being said when words no longer have any clear meaning 😉
peace
In your own words— What is a species?
peace
Wow, finally an intelligent question. I think of a (sexual) species as a population of individuals currently in the practice of interbreeding. Please note that such a population might be currently undergoing speciation, in that subgroups within the population may tend to breed within that subgroup more frequently than outside of it. So at some point, the amount of interbreeding between the subgroup and the rest of the population becomes infrequent enough so that it’s useful to regard the subgroup as a separate species.
For asexual organisms, I don’t think the species concept is quite so useful. Since there is no interbreeding, the groups must be sorted some other way – say by physical properties, or by behavioral properties. But if, as often happens with bacteria, populations mutate rapidly (say under the selection pressure of antibiotics), the notion of a species of bacteria might not be very useful.
Please notice my emphasis here on utility of the concept. What I mean by that is, the word must be agreed on between two people using it, as to what it refers to. As Robin said, similar to words like “big”.
(And incidentally, ALL words are human conventions, conveniences of language. Since reality is infinitely complex and vocabularies are limited, words must be flexible and malleable enough to communicate ideas more or less accurately – and clearly, they often fail to do this task as well as some might prefer.)
I say there is no such thing as a species. Reproducing or not is just a coincedence.
For both creationist and evolytionist what there must be admitted is that segregated populations are under influence and thius brings changes in thier looks relative to a previous look. Including having been in a previous population that was inclusive of more later segregated looking populations.
This is king. The influence that changes populations in looks. Usually the change is so much they can’t breed anymore with the other “species” or anyways reject doing so.
However reproductive ability is irrelevant to the new population. This is the same with humans. We have segregated looking populations but all can breed together.
Yet there is no deifferent mechanism behind our “speciation” and the rest of biology.
All there is IS segregated populations that may or may not have been biologicaly changed by some influence.mechanism.
Species should be retired as a term.
fifthmonarchyman,
FMM: “It does not sound like he is a big fan of the species concept to me “
No, I am not a fan of people who try to use the well known limitations of the species concept as an argument against evolution and in favour of creationism. Anyone with a few firing neurons would know that if evolution is true then any system of classification devised my man to categorize organisms will have some serious limitations. But having limitations is not the same as saying that it has no value.
Flint,
If everything and nothing is speciation, then everything is a road to it.
Flint,
So, like, North Koreans are a separate species?
phoodoo,
Meantime, what’s a kind?
phoodoo,
[attempting a paraphrase]
No, that’s not it. Try again.
You should repeat your own definition for the record also. As I recall you define species as what god defines species as. You can’t actually use that definition to produce useful data or talk about specific species, but it is sufficient for you to simply know that each individual species is discrete in the mind of god. You don’t know how many there are or what the boundaries are between them but you know they exist and that is sufficient.
Is that about right? Did I get anything wrong there?
Does your god bless the troublemaking gossip?
DNA_Jock,
Crap, I didn’t parse it closely enough. Now I don’t know what circular reasoning is. 🙂 May the mockery of a thousand phoodoos rain upon my unworthy head.
Heh yeah I agree, the way he wrote it it isn’t actually circular, he pretty much just reformulated the first sentence.
I think he probably meant to imply something like this:
Actually what we observe is that organisms give birth to descendants that are slightly different than themselves. They ALWAYS have mutations in them. For sexually reproducing organisms, there is recombination AND mutations.
No, we simply do NOT see any “categories”. What we see is slow accumulation of change.
No, the book is called the Origin of Species because Darwin seeks to explain how there came to exist such a broad diversity of life. Not because species refers to some immutable form.
We don’t have that experience. I have never seen any organism give birth to an absolutely identical copy of itself, ever. Even at the cellular level, and I spend 1-3 hours every day peering intensely at human cells in a microscope as part of my job.
The more I have bothered to look into the facts, the more change has become apparent.
That it is not a deception, because it (the claim that organisms stay the same) is demonstrably (as in empirically, can be seen, measured, weighed and photographed to be) false.
Your personal denial of a concrete empirical reality is not a “universal experience of humanity”. Literally millions if not billions of people the world over have experiences that are in conflict with those you purport to have.
They observationally test the predictions of a hypothesis. At a basic level it works like this:
Hypothesis: Species B and C evolved from a common ancestor A.
Prediction: If Species B and C evolved from a common ancestor A (Speciated), we should expect to find X.
Then they go out and see if X is true. This usually means taking blood samples from a large number of members from the populations of B and C, sequencing the genomes of species B and C, and seeing if the predicted X is true.
That’s how.
The particular nature of X (which could be “number of substitutions in certain key genetic loci”) will also allow a rough estimate of the time of speciation from their common ancestor, given a certain average mutation rate.
I’d like you guys to try to answer the question yourselves. I mean most creationists accept common descent within “kinds”, right? Take the Canidae (Dog) Baramin for example. Do you have a problem with the hypothesis that all the species within the baramin evolved from a specially created common ancestor? How would you define speciation within baramins? How would you delimit species within baramins? how would you tell the first coyote from it’s not-a-coyote ancestor if you could replay the tape and see every single member of the baramin tree?
By currently do you mean right now today or this week or this decade or what? Are individuals who are not currently sexually active not of the same species? What about infertile individuals?
quote:
: a particular group of things or people that belong together or have some shared quality
end quote:
from here
http://www.merriam-webster.com/dictionary/species
See how simple life can be if you take your Darwin blinders off and allow words to have clear simple definitions
peace
“Things or people…” that leaves out pretty much all of the biodiversity, doesn’t it?
Forget about Darwin. Again, please, think species within kinds. How would you define those please?
An animal is a thing, Is it not?
as in there are lots of “things” on a typical farm (cows, wheat plants, tools, hay bales, dogs, etc)
see above
peace
It doesn’t matter how simple and clear a definition you can come up with if that definition does not correspond to what we observe happens in the real world.
Things change.
essences don’t
peace
So your definition of kind is “something that has some shared quality” ?
Then ALL OF LIFE is the same “kind” under that definition. All of life is… alive!
All of life reproduces. All of life must eat to grow and survive. All of life has genomes of ribo- or deoxyribonucleic acids. All of life suffer mutations.
So if things can evolve “within kinds”, then all of life, since it meets the definition “something that has some shared quality” for a “kind” that you provided, could have evolved from a common ancestral bacterial species 4000 million years ago.
Obviously you don’t agree, which means your definition is shit. Try again.
Where do I find these essences? How do I know what the essence of some particular thing is?
Under that definition a Coyote is a Wolf. Actually since all kinds share some quality, they’re all the same species. Does that sound right to you? Do you think that’s an operational definition?
What I’m asking is, how do you define species (within kinds) in a way that helps delimit Coyotes, Wolves, and their specially created ancestor?
From that definition, buttons and french fries are a “species”. See how useless a definition can be when you don’t actually consider any context?
It is interesting to me that you didn’t grab the definition from biology. Seems given the discussion, that would make more sense. That ‘context’ thing and all…
What about trying to put out a definition for species “in your own words”?
Heh, under the definition all physical objects are the same “kind”. FFM has just proven that, under his definition, life can evolve from non-life because it would still be “within kind”.
Allan, Rumraket,
First time through, I made the same mistake – reading the tautologies as properly circular. I assumed that colewd (and Sal) were at least competent enough to construct a circular argument. John Harshman, however, was paying attention.
Strawmanning, they are doing it wrong.
fifthmonarchyman,
A definition that can apply equally to any taxonomic rank, and even applies within a population (see ‘people’) is no use to anybody.
You have to put the God goggles on if you want things to be really simple.
Peas.