Definition of Species

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Quote from FastEddy in Yahoo message 6679:
I'm sorry I can't agree with your speciation examples, but not only were they hard to locate for your sources, the conclusions were questionable as I previously explained.

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Because this is something you keep repeating, I think we need to spend a little more time on it. If I'm thinking of the right set of messages, you believe there is little agreement on the definition of species among biologists, and there was a specific webpage involved that give you this impression. I couldn't find the message with the citation for that webpage, but you seemed to believe it indicated little consensus. Can you or someone dig out a reference to it? Thanks much! (This is where threads for each topic and search capabilities really help, if you'll forgive me for putting in a plug).My guess is that you're mistaking disagreement about some very specific details of the definition of species for disagreement about the basic definition itself. Just as in particle physics, where there are a variety of perspectives on the fundamental nature of matter but no doubt whatsoever about how atoms behave, there are a variety of perspectives within biology, but no doubt whatsoever of how species behave. Species are differentiated by reproductive boundaries - it's as simple as that.Perhaps you're thinking of specific cases, such as horses and zebras, which can mate and produce sterile offspring, and that perhaps some biologists think you can only consider them the same species if the offspring are fertile, while others believe that simply producing offspring at all makes them the same species? Or perhaps of certain species of finch which very occasionally mate and produce fertile offspring with another finch species?If this is the case, then all you've done is noted a quality common to all of human experience. Computer 0's and 1's and quantum physics notwithstanding, we live in an analog world whose fabric represents a continuum of possibilities, and while we can create definitions all we like there will always be cases that walk right up to the boundaries and then cross them. The real world is a messy place. This is a quality of the nature of all existence, not just of the definition of species.--Percy

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[This message has been edited by Percipient (edited 01-25-2001).]

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[This message has been edited by Percipient, 11-27-2001]

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Quote from Larry in Topical Discussion, Is Creationism Science?, Message 3:
However, where do you feel there must be differences between the Bible and what biological evolution proposes?

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Quote from FastEddy in Yahoo message 6679:
I haven't seen the comprehensive detailed pattern of progress that evolution would have to leave as a trail to make it clear it had taken us through the history of life. Especially telling for me is the lack of transitions in our contemporary world. This divergence should be expanding relative to the increasing species and the increasing possibilities for speciation. In other words, the process should be gathering steam and we should be witnessing an explosion of evolutionary changes evident to all. Rather than the sparse forced examples that are so elusive in the first place.

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What it seems you're saying is that the theory of evolution has made some predictions, as all good theories must, that haven't panned out, in which case it should be modified or discarded. So we have to examine whether it's made the claims you say it does.I confess I'm uncertain I've grasped all you said, so please correct me if I've misunderstood, but you seem to be saying that evolution predicts the number of speciation events should be picking up because an increase in the number of species means an increase in the possibility of speciation - there are more dice so there can be more rolls of the dice, so to speak. Based on this you believe we should have far more examples of observed speciation than we do.

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Note: I didn't see this mentioned earlier in the discussion, but you are correct that biologists believe there are more living species in the world today than ever before in earth's history.

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There are a couple problems with your analysis. For one, how do you get from a qualitative assessment (more species means more speciation) to a quantitative conclusion (the number of new species Larry cited is not enough)? You could be right or wrong - you don't have enough data to know either way.Another more serious problem with your analysis is that it doesn't take into account that speciation requires available ecological niches. You state that more species should mean more speciation, but fail to also realize that more species means that speciation in such a crowded world requires ever increasing specialization to take advantage of tinier and tinier niches. When the niches are too tiny the differentiation is too small to create a new species. Man in Africa is dark skinned, man in Scandinavia is light skinned, but the difference in habitat is evidently too small to cause speciation. It caused changes to our species, but only to the point of creating new races, not new species. Squirrels east of a major highway are geographically separated from those west of it, but the difference in habitat is in all likelihood too small to cause speciation.Yet another problem is that of conclusively observing speciation, especially in the wild. Every year we discover more species (especially of insects), but it is rare that a biologist concludes speciation. Usually they conclude we simply never came across that species before (or at least no biologist did).So the bottom line is that, no, evolution does not predict that there should be increased speciation today. There are so many factors involved that I even wonder if any scientists have ever attempted such a prediction.--Percy

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[This message has been edited by Percipient, 11-27-2001]

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Quote from FastEddy in Yahoo message 6679:
I'm sorry I can't agree with your speciation examples, but not only were they hard to locate for your sources, the conclusions were questionable as I previously explained.

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Quote from Percipient in Topical Discussion, Definition of Species, Message 1:
Because this is something you keep repeating, I think we need to spend a little more time on it. If I'm thinking of the right set of messages, you believe there is little agreement on the definition of species among biologists, and there was a specific webpage involved that give you this impression. I couldn't find the message with the citation for that webpage, but you seemed to believe it indicated little consensus. Can you or someone dig out a reference to it? Thanks much!

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Quote from FastEddy in Yahoo message 6696:
Here it is. Note the lengthy preface explaining the multiple definitions of speciation. Also the apologetic revelation of the writer's difficulty in unearthing these examples and his reasoning...(paraphrase),"Examples? Well sure...You have them don't you..?"- "Hey I thought YOU had them....": http://talkorigins.org/faqs/faq-speciation.html

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Thanks for the link! I read all the definitions and, as I suspected, you've drawn an unwarranted conclusion. What you've done, in essence, is said, "Gee, there are definitions from a variety of factions, including the naturalists, the biologists, the morphologists and the phylogeneticists. Obviously there's no agreement, and this invalidates any conclusions regarding speciation."What you've failed to note is the similarity in the definitions. For most lifeforms that we're familiar with on a common experience level all the definitions will reach the same conclusions. For example, all the definitions would say that a Saint Bernard and a Chihuahua are members of the same species, but that dogs and wolves are different species.The requirements of science for precision are what drives this variety of definitions, but they are only attempting to deal broadly with all cases that might and do arise. As this webpage also states, the biological species concept (BSC) has been very successful for vertebrates (ie, mammals, birds, amphibians, reptiles and fish) and some groups of arthropods (insects, crustaceans, arachnids, etc). Outside this arena the definition is less successful and so other definitions must apply.This is precisely consistent with my previous message: the world is a messy place. It wasn't designed to fit into neat categories.That being said, roughly 50% of the article deals with examples of speciation using the rather rigorous and unambiguous BSC definition. For the rest of the examples he specifies what definition applies, and even mentions ambiguous cases.By the way, you've misrepresented the article's content with the paraphrase, "Examples? Well sure...You have them don't you..?"- "Hey I thought YOU had them...." There's nothing like that in the article. You're probably thinking of the fourth paragraph:

I consider this FAQ incomplete. One reason for this is that I am still chasing references (I still have a list of over 115 to find). More important is the fact that observations of speciation are buried in papers on a number of topics. If you know of observations that I should include, let me know and I will chase down the reference, read it and modify the file (assuming that the data are the least bit convincing). I ask that you try to give me as complete a reference as possible to aid me in finding the original source.

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Quote from Percipient in Topical Discussion, Definition of Species, Message 1:
You seem to be saying that evolution predicts the number of speciation events should be picking up because an increase in the number of species means an increase in the possibility of speciation - there are more dice so there can be more rolls of the dice, so to speak. Based on this you believe we should have far more examples of observed speciation than we do.

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Quote from FastEddy in Yahoo message 6696:
If it is supposed in a decreasingly hostile world, a single species diverged into a vast multiplication of life forms, it seems reasonable.

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So you're saying that because evolution postulates that all modern life forms are descended from a single life form originating billions of years ago, it therefore follows that evolution predicts increased speciation in the modern world. If I've correctly stated your thesis then it still makes no sense. Your conclusion doesn't follow from your premise. Perhaps you need to explain this at greater length.You also need to explain what you mean by a decreasingly hostile world. I'm guessing that this is your way of referring to open ecological niches. If that's the case, what leads you to believe ecological niches are opening up today? Most people conclude the opposite, that man's actions are shutting down many ecological niches through polution, overuse, destruction of habitat, etc.

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Quote from Percipient in Topical Discussion, Definition of Species, Message 1:
For one, how do you get from a qualitative assessment (more species means more speciation) to a quantitative conclusion (the number of new species Larry cited is not enough)? You could be right or wrong - you don't have enough data to know either way.

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Quote from FastEddy in Yahoo message 6696:
I theorize, based upon the evidence of what had to have taken place to present us with the diversity of life we see today, that these same processes would continue today.

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Proceeding upon the assumption that processes we believe to have happened in the past should continue in the present is very well founded, and so what you're saying is that since we've observed speciation into open ecological niches in the past that the process should be continuing in the present. And we do observe it in the present, as described in detail by the referenced article. By what you've done is gone from a qualitative assessment (we should be observing speciation today) to a quantitative one (the amount of speciation we observe today is less than that expected). How do you get from qualitative to quantitative? More fundamentally, how do you even justify your qualitative assessment given that your assumption about increasingly available ecological niches in the modern world is questionable at best?

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Quote from Percipient in Topical Discussion, Definition of Species, Message 1:
It doesn't take into account that speciation requires available ecological niches. You state that more species should mean more speciation, but ... more species means that speciation in such a crowded world requires ever increasing specialization to take advantage of tinier and tinier niches.

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Quote from FastEddy in Yahoo message 6696:
Is this indicated? How would lack of a niche prevent speciation from occurring? Is our "crowded world" denying any new mutant deviations the chance for nutrition and reproduction? I'm not convinced.

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The answer is yes. An individual in possession of a mutated characteristic that better adapts it to a nearby ecological niche that is already occupied has received no advantage. If he has gained that characteristic at the expense of his adaptation to his current niche then he is less well adapted.Let's take a hummingbird example. Hummingbirds have long slender beaks that allow them to extract the nectar from deep tubular flowers. A hummingbird with a mutation giving it a longer beak allowing it to take advantage of even deeper flowers would have an advantage over its mates. But what if there were already a species of hummingbird that was slightly larger and more aggressive taking advantage of the deeper flowers? And what if the longer beak gave the hummingbird slightly diminished aerodynamics and made it less attractive to potential mates? The costs outweigh the benefits, and this hummingbird is less likely to pass on its characteristics to offspring.Keeping with the hummingbird example, there's another possibility. Let's say no other hummingbird species is taking advantage of the deeper flowers, but that a slightly longer beak is simply an insufficient mutation to cause speciation. The longer beak becomes another variable characteristic of the hummingbird population. Some hummingbirds will have longer beaks, some shorter, just like humans have larger and smaller noses. If the longer beaks actually confers a survival advantage then it will become a very common characteristic, but more likely the availability of deeper and shallower flowers is variable from season to season and year to year, and the relative availability of each will govern the frequency of longer beaks in the hummingbird population.--Percy

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[This message has been edited by Percipient, 11-27-2001]

Percy: For example, all the definitions would say that a Saint Bernard and a Chihuahua are members of the same species, but that dogs and wolves are different species.Moose: Nitpicking, but I'm pretty sure dogs and wolves are the same species.Mooseps: The blue print on grey background causes eye strain

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[This message has been edited by minnemooseus, 11-26-2001]

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[This message has been edited by minnemooseus, 11-26-2001]

Hi Moose,Dog and wolf are classified as different species (Canis familiaris for dogs, Canus lupus for the grey wolf). I wonder if they're mutually infertile, though. I've got some vague recollections of stories about dogs and wolves mating.But as you note, this is a minor point. Even if I chose a poor example with wolves and dogs, the point I was trying to make was that you need different definitions of species for different classes of animals. Perhaps I should have used the example of needing a different definition of species for sexual creatures like mammals than you do for asexual creatures like amoeba.--Percy

Just a thought but in a "decreasingly hostile world" wouldnt there be less evolution as the condition for the species to adapt to a threat or become extinct would be diminished?

Percy,
I agree with all you say. Creationists have a problem with evolutionary trees & speciation. The idea seems to be that the more species there are, the more chances for speciation would exist. This is true in an infinate world of infinate ecological niches. the problem is that world is only so large & most niches have been occupied since time immemorial. so to generalise, if there is a speciation, then that new species has to be ; a/ better than the parent species in its own niche, causing the original species to be supplanted. b/ Better than a species in a niche different to the parent species, causing an exinction of another species. This leads to similar species occupying slightly different areas of specialisation. eg. the big cats in Africa. Note in both of the cases above the number of species REMAINS THE SAME, despite speciation having occurred.A good analogy (metaphor?) would be to imagine the sum total of ecological niches on earth as being represented by the width of a piece of paper. Time would be represented as the length of this extremely long piece of paper. Imagine the Cambrian explosion, a conventional evolutionary tree would arise, branching with new species & phyla. But wait! the niches have all been taken up & the tree has equalled the papers width. This is where true natural selection takes over, if any new species is going to appear it has to push someone over the edge of the paper into extinction. At the very least, if a niche is to be shared then general populations must drop. After the Cambrian explosion this is exactly what happened. Once the easy life was over, entire phyla were decimated."Man in Africa is dark skinned, man in Scandinavia is light skinned, but the difference in habitat is evidently too small to cause speciation. It caused changes to our species, but only to the point of creating new races, not new species."I would go further. If the racial populations were kept separate then it is entirely possible that the races WOULD become sepatate species. The fact that they would be separate could guarantee it alone. With 90 mutations in every sperm & egg, & various mutations becoming general in DIFFERENT RACES, then, sooner or later no species will produce fertile young, & speciation will have occurred.I do have a question regarding race for the creationists. How do they account for races given that there were only middle eastern people on the Ark? Thats 5 major races, plus subraces, some of whom are geographically separated by sea, nay OCEANS! They could only have got there AFTER the floods had abated. So I'm asking how they achieved colonisation of the globe in 4,000 years whilst managing to diversify into all the races?Mark------------------
Occam's razor is not for shaving with.

I know this is an old topic but I couldn't help but find this interesting. I'm not sure, but it may be a bit of an answer as to the meaning of kind. The term species actually originated from the ancient Latin language. In this language, the word species means kind.I'm sure some, if not most of you already knew this, but what's this say about the translation of the word kind in Genesis? Could it just have well been species?

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Originally posted by RetroCrono:
I know this is an old topic but I couldn't help but find this interesting. I'm not sure, but it may be a bit of an answer as to the meaning of kind. The term species actually originated from the ancient Latin language. In this language, the word species means kind.

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I'm sure some, if not most of you already knew this, but what's this say about the translation of the word kind in Genesis? Could it just have well been species?

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I can't say anything about Biblical translations.I can, however, say something about how "kind" is used.So far, according to what I have read of Baraminology, there are a lot of groupings of "kinds" which are not justified in any systemic way. The Bible is used as the first guide of what "kinds" animals fall into, rather than the morphology and genetics of the animals themselves. IOW, there is no way that someone could just learn the criterion to be able to put animals into "kinds" by just looking at morphology and genetics. A inerrant religious book supercedes all evidence found in nature which may contradict it.For example, Chimps and humans are ALWAYS separate "kinds", and there is NEVER any justification or objective criterion for why they are classified as such. It is simply, "The Bible says so, so we will now become blind to morphological and genetic evidence."------------------
"We will still have perfect freedom to hold contrary views of our own, but to simply
close our minds to the knowledge painstakingly accumulated by hundreds of thousands
of scientists over long centuries is to deliberately decide to be ignorant and narrow-
minded."-Steve Allen, from "Dumbth"

The definition of what a species is, has become a matter of discussion in another topic (intelligent design, right and wrong - message 91, also see higher up in the thread) - so I thought I'd revive an oldie but goodie.By the way, I think the message that this is a reply to might very well have been my first message posting at . I had become a member (#88) 15 days earlier.Anyhow, Percy had replied that he thought that dogs and wolves were considered seperate species. Dog - Canis familiaris, Grey Wolf - Canus lupus.Way back, I asked veterinarian friends about this - they didn't know. Doing the web search didn't come up with a strong answer. I found the dog to be listed as either Canis familiaris or Canis lupis familiaris. I would personally be inclined to go with the second - the dog being a subspecies or breed of the grey wolf. I know you can get such a thing as a dog/wolf hybred. I don't know if that hybred would tend to be sterile.Moose[This message has been edited by minnemooseus, 05-28-2003]

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I know you can get such a thing as a dog/wolf hybred. I don't know if that hybred would tend to be sterile.

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When I lived in Alaska (just one year) everyone understood most sled dogs were part wolf, and the owners bred the dogs. A friend of mine bought a dog that was 3/4 North American Wolf. He never bred it, but it was sold as a fertile dog.I guess this quote from the Continental Kennel Club (Page Not Found) should settle it:

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Some of the most common breeds of dogs that are crossed with wolves and wolf hybrids are Alaskan Malamutes, Siberian Huskies, Eskimo Dogs, German Shepherds, Great White Pyrenese, and Belgian Sheepdogs.

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Yep, fertile offspring. They specifically mention Grey Wolf, Timber Wolf, and Red Wolf hybrids being bred with the above mentioned dogs.On the other hand, my "Complete Idiot's Guide to Evolution" lists dogs as Canis familiaris and wolves and Canis lupus. I didn't realize there was any debate about the subject.

I think I revived some of this discussion.It seems to me that if we took the full range of existing dog breeds and "extincted" all of them except for Great Danes and Chichihuahuas we'd have to distinct species left.My though experiment is this:
Take a number of breeding pairs of all breeds and put them into two different enviroments. One which favours large size (say it's cold) and one which favours small size (say an island of limited resources).What might you expect to happen.In the cold, the larger breeds would be left. Let's say something like a Great Dane or more likely a St Bernard. On the island the small would be, say the toys and chichihuauahs.Now allow contact between the two groups. We would I think see speciation had occured. And this would be [i]without any differences in the breeds[i] that exist today.Now what does this mean? How many decades did it take to force this degree of separation. A few hundred years. Talk about punq eq!Could there be such extremely focussed conditions in a natural selection environment. I would say that it would occur on occasion.

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Could there be such extremely focussed conditions in a natural selection environment. I would say that it would occur on occasion.

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I'm a total believer in that kind of punq eq. However, my opinion on that matter is hardly worth much. In biology, I'm a real novice.

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It seems to me that if we took the full range of existing dog breeds and "extincted" all of them except for Great Danes and Chichihuahuas we'd have to distinct species left.

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I'm glad you said this. I didn't want to sound stupid, but it seemed really odd to me that every definition of species would leave St. Bernard and Chihuahua in the same species. They clearly would not breed, and probably could not produce any viable offspring unless you helped them in the laboratory.How much time would it take for the Chihuahua to be so much like a rat that we'd classify it as a rodent? Well, in nature, it would probably never happen, because Chihuahuas are a mess physically, and they'd just go extinct.

So basically you are saying that dogs are a ring species?

We actually seem to have a couple of parallel threads going on. You might be interested in my sort-of response to this question in this post - off topic there, but might be worth discussing here.[This message has been edited by Quetzal, 05-29-2003]