Define 'species'

[mark kennedy]

Mark, I don't know whether they split because I have not read up on those hominids, not because of any *disbelief* in a presented theory. I have only recently turned to the hominid line-up, having read the Scientific American special edition covering the various debates and currently listening to a college lecture series on Bilogical Anthropology.

You are not heading for a "God of the gaps" concept, are you? Always dangerous.

God I hope not! What I am trying to get a handle on is the distiction between ancestors of humans only and ancestors to humans and apes. To my way of thinking there can only be apes as distinct from humans and the transitionals while interesting are hardly conclusive proof of common ancestory. In the classification of these fossils there are allways critical questions and they seem to get even more puzzling as you get into the transitional forms. This is leading me to question the role of transitional in speciation altogether. One of the primary reasons I think this has merit is the long periods of stasis (equilibrium?) where very little changes in the inherited traits and virtually all substantial mutations are either elimanated or dangerous to the species.

Just a word about Mendel and I really don't intended to elaborate at length on the analogy offered. Mendel discovered that in 3 generations the offspring would revert back to the traits of the grandparents. Thats why I am growing increasingly skeptical of the snowball effect of microevolutionary changes. But as far as the building analogy, if they don't lay the foundation to specs then they will have to tear it out and pour a new one. The casual obverver would see this as wastefull but a discerning mind would see that they have to square everything or the building would collapse.

 

[mikeynov]

God I hope not! What I am trying to get a handle on is the distiction between ancestors of humans only and ancestors to humans and apes. To my way of thinking there can only be apes as distinct from humans and the transitionals while interesting are hardly conclusive proof of common ancestory. In the classification of these fossils there are allways critical questions and they seem to get even more puzzling as you get into the transitional forms. This is leading me to question the role of transitional in speciation altogether. One of the primary reasons I think this has merit is the long periods of stasis (equilibrium?) where very little changes in the inherited traits and virtually all substantial mutations are either elimanated or dangerous to the species.

Just a word about Mendel and I really don't intended to elaborate at length on the analogy offered. Mendel discovered that in 3 generations the offspring would revert back to the traits of the grandparents. Thats why I am growing increasingly skeptical of the snowball effect of microevolutionary changes. But as far as the building analogy, if they don't lay the foundation to specs then they will have to tear it out and pour a new one. The casual obverver would see this as wastefull but a discerning mind would see that they have to square everything or the building would collapse.

Two questions for you (being serious, not trying to pick a fight)

1) What WOULD qualify as evidence to establish common ancestry between any two organisms in your mind? Meaning, supposing the idea were true for a second (hypothetically), what would you expect to see with common ancestry? As such, how does this differ from what we do see? I mean this in any terms you'd like - fossils, DNA, comparative anatomy, whatever.

2) If you have real doubt as to the capacity for 'microevolutionary' changes amounting to speciative events, how do you respond to empirical examples of such speciative events? You did acknowledge ring species in another thread, yes? There are examples of this in the literature, and it wouldn't be hard pointing you to many other examples of speciation, if you're interested.

 

[Aron-Ra]

You did acknowledge ring species in another thread, yes? There are examples of this in the literature, and it wouldn't be hard pointing you to many other examples of speciation, if you're interested.

Mark Kennedy already accepts speciation. In his debate with me, he has even accepted a biological relationship to Homo habilis, although (curiously) he rejects being related to Homo erectus. Go figure that out!

 

[mark kennedy]

Mark Kennedy already accepts speciation. In his debate with me, he has even accepted a biological relationship to Homo habilis, although (curiously) he rejects being related to Homo erectus. Go figure that out!

I meant Homo rudolfensis, I was so dizzy from the bizzare taxonomical semantics I typed the wrong word. Silly typos are not the same as a substantive point. I'll correct the post.

 

[pureone]

To my way of thinking there can only be apes as distinct from humans and the transitionals while interesting are hardly conclusive proof of common ancestory.

ERV's.

 

[Aron-Ra]

I meant Homo rudolfensis, I was so dizzy from the bizzare taxonomical semantics I typed the wrong word. Silly typos are not the same as a substantive point. I'll correct the post.

There is some contraversy that Homo rudolfensis and Homo habilis may in fact be the same species. So correcting your typo won't do any good.

 

[Jet Black]

ERV's.

I take your ERVs and raise you some ALUs. I may as well let you in on the rest of my hand, which includes transposons in the middle of chromosome 2 (which coincidentally looks just like a merge of chimp/gorilla/orang utan chromosomes 2p and 2q,

(H=Human, C=Chimp,G=Gorilla,O=Orang Utan)

and karyotype matching


(Human=left,Chimp=right)

as well as pseudogenes and all sorts of other molecular paraphernalia.

 

[gluadys]

Just a word about Mendel and I really don't intended to elaborate at length on the analogy offered. Mendel discovered that in 3 generations the offspring would revert back to the traits of the grandparents. Thats why I am growing increasingly skeptical of the snowball effect of microevolutionary changes. But as far as the building analogy, if they don't lay the foundation to specs then they will have to tear it out and pour a new one. The casual obverver would see this as wastefull but a discerning mind would see that they have to square everything or the building would collapse.

But Mendel was not applying any selective pressure. In fact, his experiments would not have yielded the evidence they did if he had not arranged for different alleles to have similar success in reproducing themselves.

 

[Jet Black]

Ok, but I really don't think there is a brake per se, its actually subordinate to the genetic blueprint. In all the changes in the 7 traits of bean plants Mendel noted in some 22,000 experiments there was never an indication that they will ever be anything other then beans. I'd say the evolutionary changes are limited by the genetic determinism of the parents. Life has to be kept in balance which is why most mutations are either harmfull or neutral. They certainly do not account for the transition from single celled to modern diversity.

this is a flawed analysis. as a rsult of ancestry, yes the beans will always be beans, but the question is were they always beans, and in the future, will they be beans that are anything like today's beans. take flowering plants for example. most flowering plants have petals, but some flowering plants have lost their petals because they don't need them anymore, and live a life where petals are just wasteful (so the petals get lost). an example of this is the spurges. now there is an interesting example in the spurges, namely poinsettia (Euphorbia pulcherrima) which have re-evolved a life where they need to attract insects, however they don't do this with petals, in stead the top leaves are bright red. so they are still flowering plants, but nothing like any other flowering plants. just like bulldogs are still canines, but nothing like wolves adn humans are still primates, but nothing like our ancestors and so on. creationists often have this problem in which they say "well beans will always be beans" and so on - and that is true, but evoution is not time symmetric, so you cannot therefore say that beans were always beans.

 

[Aron-Ra]

Two questions for you (being serious, not trying to pick a fight)

1) What WOULD qualify as evidence to establish common ancestry between any two organisms in your mind? Meaning, supposing the idea were true for a second (hypothetically), what would you expect to see with common ancestry? As such, how does this differ from what we do see? I mean this in any terms you'd like - fossils, DNA, comparative anatomy, whatever.

2) If you have real doubt as to the capacity for 'microevolutionary' changes amounting to speciative events, how do you respond to empirical examples of such speciative events? You did acknowledge ring species in another thread, yes? There are examples of this in the literature, and it wouldn't be hard pointing you to many other examples of speciation, if you're interested.

Hey, Mark Kennedy. Why did you answer my comment on this post, but you didn't answer the questions directed at you in this post?

 

[Loudmouth]

God I hope not! What I am trying to get a handle on is the distiction between ancestors of humans only and ancestors to humans and apes. To my way of thinking there can only be apes as distinct from humans and the transitionals while interesting are hardly conclusive proof of common ancestory.

So how do you explain fossils that have more ape characteristics than any human alive and at the same time have more human characteristics than any ape alive. Also, how do you explain that the human characteristics become more apparent over time and the ape like characteristics disappear over time. This would seem to be exactly what we would expect to see if humans and apes shared common ancestory.

In the classification of these fossils there are allways critical questions and they seem to get even more puzzling as you get into the transitional forms.

What is never in question is their very transitional nature, having both ape and human characteristics.

Just a word about Mendel and I really don't intended to elaborate at length on the analogy offered. Mendel discovered that in 3 generations the offspring would revert back to the traits of the grandparents.

This shows your inexperience with genetics. Every generation had the same traits. What changed was the phenotype due to the mixture of alleles. The grandchildren reverted back to the phenotype of the grandparents not because mutations changed back but because dominant alleles were bred back in. I think you may want to brush up on your genetics.

Thats why I am growing increasingly skeptical of the snowball effect of microevolutionary changes. But as far as the building analogy, if they don't lay the foundation to specs then they will have to tear it out and pour a new one. The casual obverver would see this as wastefull but a discerning mind would see that they have to square everything or the building would collapse.

You totally missed the point of the analogy. You claim that Mendel's experiments did not evidence any evolutionary changes. I agree. It is due to the short time period in which Mendel studied the pea plants. Therefore, it is just a disingenous for you to use this as an example of evolution not happening as it is for me to claim that sky-scrapers are not built by humans after watching them for 15 minutes. In other words, you are being very dishonest in the way that you present scientific evidence.

 

[Jet Black]

Hey, Mark Kennedy. Why did you answer my comment on this post, but you didn't answer the questions directed at you in this post?

probably because the last time anyone unambigiously said what they would accept as a transitional resulted in their immediate and utter pwnage, at which point he changed his definition of transitional and ran away. Mark will be the one who asks for all the "mosnters" that he thinks are required as a part of evolution, probably as a massive misunderstanding of dawkins' concept of gene space. we asked him for ages if he actually understood by the concept and he never went into it, and never displayed any understanding of it. it wuz teh phunneh

 

[gluadys]

But how do they add up? We have dominant and recessive genes in 3:1 ratios and there are times when no evolution actually occures and we have a mathmatical formula for that. So what happens to the ration of dominant and recessive genes since somehow the dominant genes don't keep the inheritance of traits at the normal ratio?

I've been puzzling for some time what your thinking is here and I still can't quite make it out.

Are you connecting the 3:1 phenotypic ratio Mendel found in some way with natural selection? Are you assuming that the dominant/recessive relationship which governs the expression of alleles in the phenotype is related in some way to selective fitness?

You are aware (I hope) that a phenotypic ratio of 3:1 is based on a 1:1 ratio of dominant and recessive alleles in the genotypes.

And that should selective pressure favour one allele over the other, it can be either the dominant or recessive allele which is so favoured.

 

[Aron-Ra]

probably because the last time anyone unambigiously said what they would accept as a transitional resulted in their immediate and utter pwnage, at which point he changed his definition of transitional and ran away. Mark will be the one who asks for all the "mosnters" that he thinks are required as a part of evolution, probably as a massive misunderstanding of dawkins' concept of gene space. we asked him for ages if he actually understood by the concept and he never went into it, and never displayed any understanding of it. it wuz teh phunneh

That was the impression I got in our private debate too.

 

[mikeynov]

Two questions for you (being serious, not trying to pick a fight)

1) What WOULD qualify as evidence to establish common ancestry between any two organisms in your mind? Meaning, supposing the idea were true for a second (hypothetically), what would you expect to see with common ancestry? As such, how does this differ from what we do see? I mean this in any terms you'd like - fossils, DNA, comparative anatomy, whatever.

2) If you have real doubt as to the capacity for 'microevolutionary' changes amounting to speciative events, how do you respond to empirical examples of such speciative events? You did acknowledge ring species in another thread, yes? There are examples of this in the literature, and it wouldn't be hard pointing you to many other examples of speciation, if you're interested.

^^^

Still very curious to hear Mark's thoughts on the above.

 

[Vance]

What finally convinced me is that some of the fossils are SO transitional that even the Creation Science "scientists" disagree over whether they are ape or human. If they are so much a mixture of the features that they can't fall clearly into either category, then that is VERY good evidence that they are something in the line of development between an ape-like predecessor and modern human (whether or not in the exact line, if you follow the bush theory).

 

[lucaspa]

That said, I don't see how you can have it both ways. Either it is a long successive accumulation of microevolutionary changes or something happens relativly suddenly and the species is inalterably changed.

Have you read Gould on PE?

"Punctuated equilibrium is neither a creationist idea nor even a non-Darwinian evolutionary theory about sudden change that produces a new species all at once in a single generation. Punctuated equilibrium accepts the conventional idea that new species form over hundreds or thousands of generations and through an extensive series of intermediate changes. But geological time is so long that even a few thousand years may appear as a mere "moment" relative to the several million years of existence for most species. Thus, rates of evolution vary enourmously and new species may appear to arise "suddenly" in geological time, even though the time involved woudl seem long, and the change very slow, when compared to a human lifetime." Stephen J. Gould, Science and Creationism, A view from the National Academy of Sciences, 2nd edition, pg 29, 1999. www.nap.edu

I actually believe that Darwinian thought has great merit but the level of change that is discribed by Darwinians has to be qualified, quantified and demonstrated.

Been there, done that, bought the T-shirt. Rates of change in the fossil record have been quantified and qualified:
5. PR Sheldon, Parallel gradualistic evolution of Ordovician trilobites. Nature 330: 561-563, 1987. Rigourous biometric study of the pygidial ribs of 3458 specimens of 8 generic lineages in 7 stratgraphic layers covering about 3 million years. Gradual evolution where at any given time the population was intermediate between the samples before it and after it.
6. PD Gingerich, Paleontology and phylogeny: patterns of evolution of the species level in early Tertiary mammals. American J. of Science, 276: 407-424, 1980.

Among living species, rates of change have also been quantified. A single example is:
2. Reznick, DN, Shaw, FH, Rodd, FH, and Shaw, RG. Evaluationof the rate of evolution in natural populations of guppies (Poeciliareticulata). Science 275:1934-1937, 1997.

In fact, rates have been so quantified that there is a special unit of morphological change, the darwin. A darwn = ln of one unit (mm or whatever) per million years. ln= natural logarithm. So change is measured by the natural log/time. Change in the fossil record is about 0.3 darwins or less.

What I was curious about is how the evolutionist reconciles the two points of interest. I am satisfied that these two are at least compatable and I just wanted you guys to try your hand at synthesising the two.

Remember that PE is allopatric speciation applied to the fossil record. That is, small isolated populations evolve via gradualistic change. This is usually unseen because it happens someplace else where the fossils aren't exposed. Then the new species migrates into the region where the paleontologist is digging fossils. In that area, the species appears "suddenly".

 

[lucaspa]

What I am trying to get a handle on is the distiction between ancestors of humans only and ancestors to humans and apes. To my way of thinking there can only be apes as distinct from humans and the transitionals while interesting are hardly conclusive proof of common ancestory.

I'm interested in how you deal with the recent fossils from 5-7 million years ago (3 species) that do not have characteristics that allow them to be distinct apes or distinct humans. They are very close to the split in lineages. So close that people argue heatedly over which side of the split they are on.

In the classification of these fossils there are allways critical questions and they seem to get even more puzzling as you get into the transitional forms.

The classification is going to be difficult as the individuals lie between 2 species. They are transitional between them.

"This primitive configuration of pongid and hominid traits has led the discoverers and describers of these early Australopithecines to assign them to a new species. If the first Australopithecines to be discovered is properly Australopithecus africanus, the early ones, they suggest, should be Australopithecus afarensis. Not al scholars agree. I have to confess that, although I have had the opportunity to handle both the Ethiopian and the South African material with which it is being compared, and although I agree with virtually all of what its describers say in regard to its tendency to be more primitive in a series of traits, I am not convinced that the differences are pronounced enough to warrant separate specific recognition. ...
"Our disagreement is merely a matter of the assignment of names. This is based on the judgement of the individual scholars and is a trivial matter, but it does point up an issue of fundamental significance. In an evolutionary continuum, change occurs more or less gradually through time. At the early and late ends of such change, everyone agrees that different names are justified, but when one form slowly transforms into another without break, the point where the change of name is to be applied is a completely arbitrary matter imposed by the namers for their convenience only - it is not something compelled by the data." C. Loring Bruce, "Humans in time and space." In Scientists Confront Creationism, edited by LR Godfrey, 1983, pp. 254-255.

This is leading me to question the role of transitional in speciation altogether. One of the primary reasons I think this has merit is the long periods of stasis (equilibrium?) where very little changes in the inherited traits and virtually all substantial mutations are either elimanated or dangerous to the species.

Ever hear of "fitness peaks"?

Just a word about Mendel and I really don't intended to elaborate at length on the analogy offered. Mendel discovered that in 3 generations the offspring would revert back to the traits of the grandparents.

Reference for that, please.

 

[Jet Black]

That was the impression I got in our private debate too.

yeap, I have been watching that. he tends to skit around the edges and argue about silly little semantic things, rather than get into the real meat and potatoes of the argument. It's a bit annoying because he is an intelligent chap from all impressions, but he is unwilling to expose his core ideas to scrutiny. This is one of the issues with the new "creationist only" forum - if the ideas are right, then why are they so afraid of exposing them?

 

[Jet Black]

Reference for that, please.

I think Mark is misunderstanding the point of Mendel's experiments, namely the particulate heritability of (certain) characteristics (certain, because Mendel didn't know about things like pleiotropy) rather than the effect of selection pressures. It is similar in a sense to John's mistake on Hardy Weinberg equilibrium. I guess you already know this though, which is why you are asking for a reference, because it will be his own research, assuming he does it, that shows he is wrong, and hopefully encourages him to check up on things before he says them.