Let us reason together.

Just out of curiousity, was there anything of particular substance in that post that you'd like to discuss relating to evolution vs creationism (like, evidence for a perfect world specially created 6000 years ago, the difference between "common ancestor" and "descent from monkeys", etc)?

Soooo, I can take it the answer to my question... ... is "No.", then?

[quote]A non-dog change into many breeds of dogs, which if shown to a naturalist and labeled 'wild animals' he would definitely assign them to different species ('Canis dobermanni...Canis chihuahuanensis...[i]Canis sancta-bernardi[/]...'). The non-dog is a wolf. That simple enough?[/quote]This is great, Andya. The truth is that "dog" and "wolf" shouldn't be considered different species, since fertile backcrosses occur in nature. Wolves and dogs share 99%+ the same genomes. Here's a good site discussing wolf-dog hybridization Wolf-Dog Hybrids, which includes some of the genetics. It appears that it should be Canis lupus dobermanni . Now, my question is, if we are strictly adhering to the biological species concept, would some DOG breeds be considered different species? Anyone know of a "natural" cross between a chihuaha and a great dane (say, living in the same house)?

I smell a "kinds" discussion coming on.

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The ark was 45 x 75 x 450. It could easily fit them all.They only need two dogs. Not every different kind. We see all different kinds of dogs with longer or shorter noses, colors, shapes, etc. Just as man or any other animal. Are they still dogs? Yes.

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Okay, there were two dogs(Canis lupus familiaris). Were there also two wolves (Canis lupus)? How about two golden jackals (Canis aureus) and two black-backed jackals (Canis mesomelas)? Any other wolves (like Canis rufus or Canis simensis)? How about non-canis dogs like the "small eared dog" (Atelocynus microtis) or the African hunting dog (Lycaon pictus)? Any other canids? Say, foxes? Get the picture?The problem you've got with the Ark assertion you made - setting aside for the moment the mind-boggling engineering problems to overcome in making a boat that big out of wood with no metal and having it actually able to float - is that you're gonna have to define the "kinds" that were on the thing. If you're gonna say that "there was plenty of room", you'll need to figure out exactly what there was plenty of room for. After all, we have approx. 1.8 million identified species (with a scientific name) today, with an estimated 11-13 million total species (or extreme estimates up to 80 million counting single-celled organisms, which I suppose you could keep in a jar or something). That's a heck of a lot of critters, even if each one was no bigger than your average dog...So, care to define "kind"?

No, no - you're jumping the gun. (Shhh, you'll ruin the surprise.) First we have to determine how many kinds were on the Ark.Then we have to determine how all those kinds survived after the Flud long enough for the ecosystem to recover from a mass extinction event that was worse than all the others combined (they have to eat something while repopulating the Earth, no?)Then we have to determine how any kind survived from a start so far below any reasonable minimum viable population, especially without leaving any genetic evidence of it.Then we have to figure out how flash adaptive radiation and lightning fast speciation occurred in only 4500 years.Then and only then do we have to figure out biogeography.

Hi greyline: Welcome to EVCforum!

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It's been a decade since I did my biology degree so I may have this wrong, but I wanted to clarify the above. And it probably should be a new topic but it's a wee thing: doesn't the definition of "species" include not only "able to produce fertile offspring" but also some consideration of behavioural patterns to allow individuals to recognise each other?

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Nope, you're not wrong. The post you were responding to contained something of an over-simplification (after all, it was designed to be illustrative, not authoritative ). In essence, the biological species concept states simply that, for two populations to be considered distinct species, there must be some type of reproductive barrier that prevents natural hybridization. The barrier can be pre- or post-zygotic. Examples of pre-zygotic barriers (which is what I think you were referring to)include things like ecological isolation, temporal isolation, behavioral isolation or structural isolation - or, just to keep things interesting, a combination of any or all. Post-zygotic barriers include things like hybrid inviability, hybrid sterility, or loss of fitness (although this is a tough one requiring a negative result after n generations). "Species" is a squishy term, anyway. It's a convenient, general rule of thumb - and generates myriads of exceptions, just like every other rule in biology. And, of course, this is where the creationist argument about "kinds" breaks down so thoroughly - since there's no real way of absolutely defining a species 100% of the time, there's even less evidence of the unbreachable taxic discontinuity required by "kinds".

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There are many species that are easily cross-mated in theory, but would not mate with each other in the wild because they have evolved incompatible mating rituals. I wonder if a poodle let loose in a wolf lair would actually mate with the wolves? (Well, maybe it would think that was fun - especially if it had led a sheltered life.)

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Yeah, the whole thing is dependent on "in the wild" vs artificially crossed. After all, zoos have created ligers - but even in India where lion and tiger ranges overlap, there are no natural crosses. As for dogs and wolves - here's one of those marvelous exceptions that keeps biology so interesting. How many "real" species of dog are there? We have lots of artificially selected breeds, but how many of them - if left to their own devices - would encounter reproductive barriers? I would say that likely the ones on the extremes (such as chihuahua vs great dane, for instance) would be considered different species (and probably even different genera) if encountered "in the wild". The wolf/dog hybrid example is another "exception", if you will. It's a fun one to use with creationists when they start in about their "kinds". Since dogs will always be dogs, what happens when they're wolves? Are wolves dogs as well, or vice - versa? Are they different kinds? If so, why can they interbreed in the wild? If wolves and dogs are the same kind, what about foxes? etc etc etcAnyway, this is a longer response than you probably need or wanted.

Numbers in reply refer to cited post:1) You believe that evolution is a blind faith belief. As of yet, you have offered no support for this assertion. What is the basis for your belief?2) Nor does anyone else. You either have erected a strawman or have not understood the explanations provided.2 bis (you duplicated a number here, but I assume you meant #3) There are a numerous examples of fossil organisms that show distinctive traits across species, genus, family and even order boundaries (IOW, that contain traits of one or more). To give a valid example, it would be incumbent upon you to define what you would accept as a "transitional form". Please do so now.4) There have been no verified fulfilled prophecies. Beyond that, the Bible's value as a "history book of the universe" is questionable, to say the least, as even those historical and/or observations that are made in it are in large measure erroneous. You're better off using Moby Dick as a science reference - after all, there really ARE whales.5) How are you defining natural selection without reference to evolution? Quoting from my as-yet unfinished essay on the subject, Evolution DOES create "new information" - any change in the genotype of a species or population axiomatically adds new information (information that was not previously present) to that genotype or population. Please demonstrate, using either living or extinct organisms, the evidence behind the assertion "things are winding down". In what way, and from what point is this occurring? How do you determine that an organism, species, population, community or ecosystem has "lost information". Be specific.5) The most recent work I've read on the evolution of language is that it is the result of pre-adaptation unique to Homo sapiens, and may have played a key role in the ultimate dominance of this species. As such, it would have been more on the order of 150-200,000 years ago, not 5000. We can presume that langauge played a role in social organisation of the first "civilized" states around 10-13,000 years ago. Therefore, it is unlikely the Egyptians were forced to grunt when constructing their monuments. However, you will need to provide evidence of some kind that "man has always been advanced". You can start by explaining what "advanced" means in this context. After all, even Australopithecines were able to fashion crude tools.7) Contrary to your assertion, we don't see "kinds". We see divergeant populations of various organisms, some closely related (which we group into species or genera), some nearby populations which are unrelated. In addition, we see significant variation from one end of even species ranges to the other - ring species being a prime example. There is no taxic discontinuity (the requirement for "kinds) observable in nature. If you think that such exist, please provide a concrete example. In addition, please explain the biological mechanism that prevents one "kind" from becoming another "kind" over geological timeframes and/or operationally define "kind". And yes, dogs are still dogs, except when they're wolves (or foxes) as I noted above. Are wolves and dogs different "kinds"?8) See edge's reply.9) How are you defining complex? I would like to see some evidence that leads you to believe "cells are the most complex systems". And no, they weren't "thrown together". Of course, if you had read the website schraf linked you to, you'd have known that.10) Incorrect. The last of the main dino lineages died out around 65 mya. The only related lineage that still exists are what we call birds. "Most dinos were the size of chickens?" Where do you come up with this stuff? Giganotosaurus was a 12 meter long carnivore with 16 cm teeth! Bit bigger than a chicken, I'd say. No one has found any dino in the Congo. And as for dinos being hunted to extinction by humans, the odds are it would have been the other way around unless early humans were armed with antitank weapons.11) Yeah, well that's the question isn't it? "IF the bible were true...". So far, you haven't provided anything to support this assertion beyond it makes you feel good. Bible thumping and faith testimonials do not an argument make.One last bit: you state, "I love science". How on Earth can you make this statement yet at the same time reject everything science is based on?

Okay, drum. To expand a bit on what Taz and Schraf et al have explained about evolution, I thought I'd repost something I put on evcforum a while back.First off, there are some very basic statements that, for evolution to be true, must be true. All provide potential pathways for falsification. All lend themselves to development of testable hypotheses. All have (scientifically) predictive value:1. If all the offspring that organisms can produce were to survive and reproduce, they would soon overrun the earth.2. As a consequence, there is competition to survive and reproduce, in which only a few individuals succeed in leaving progeny.3. Organisms show variation in characteristics or traits that influence their success in this struggle for existence. Individuals within a population vary from one another in many traits.4. Offspring tend to resemble parents, including in characters that influence success in the struggle to survive and reproduce.5. Parents possessing certain traits that enable them to survive and reproduce will contribute disproportionately to the offspring that make up the next generation.6. To the extent that offspring resemble their parents, the population in the next generation will consist of a higher proportion of individuals that possess whatever adaptation enabled their parents to survive and reproduce.Next, you need to understand (and remember) that natural selection leading to evolution is simply the differential reproduction of genotypes. There are two basic assumptions for natural selection to work:1. There must be heritable variation for some trait. Examples: beak size, color pattern, thickness of skin, fleetness, visual acuity.2. There must be differential survival and reproduction associated with the possession of that trait.Heritable variation occurs by mutational changes in an organism’s DNA (any change in the hereditary message — base pair substitution or insertion/deletion of new bases) leading to the creation of new genetic material AND/OR creation of new genetic combinations through transposition (changing the position of a gene changes what it does), recombination (through cross-over during meosis), or genetic reshuffling (through sexual reproduction). Without getting too deep into it, selection can only act on the phenotype. A gene can be present, but not expressed (e.g. a recessive allele). Only homozygous recessives will show the trait and be selected for or against. In addition, selection acts on the whole organism (a conspicuously-colored moth, for ex, can have all sorts of wonderful genes, but if a bird nails that moth, its entire genotype is gone). And finally, selection doesn’t have to cause changes. It also can maintain the status quo.Therefore, the general predictions of evolution are:1. Given heritable variation over time, new species can and do arise.
2. Over sufficiently long time periods, due to various mechanisms surviving populations will vary sufficiently from the parent population to constitute new taxa.Does this help your understanding?(edited to delete graphic that didn't load for some reason)[This message has been edited by Quetzal, 03-21-2003]

Hey Zephan, before bothering to respond to the above, I'd appreciate your attention to your non-response on the Margulis thread. Thanks.

No doubt - I credited you in the opening paragraph of that post. However, I thought since he apparently couldn't be bothered to click on the link, I'd let him have a little synopsis in black and white here (or white and blue, I guess) where it'd be a bit harder to ignore. Now he truthfully can't say no one's given him an understandable explanation.

Actually that's probably not a bad plan. There is some good stuff here, but since the recipient apparently has no interest in discussing or even commenting on it, we can always save it for someone who DOES care about learning what evolution is about.