Evolutionary apologetics thread

[gluadys]

Thank you for taking time to explain the idea of species evolution and the cladistic speciation. So, if you will, I like to focus on the process which makes a gradual appearence of a new species. I would appreciate if you could introduce one of the best example on this process. Of course, be mercy on the use of biological jargons. I think if you use one of the best example you know, you could make a lay person like me to understand. Of course, my goal is trying to identify a hole in your good example so the evolution process would be in question. It would be OK if you give a few links as assigned readings, so it may save some of your typings.

Thanks in advance.

The ring species shernren referred to are a good place to start.

You might like to follow that with this execise (for high school students) in tracing the evolution of a group of lizard species in the Canary Islands.

http://www.ucmp.berkeley.edu/fosrec/Filson.html

 

[Mallon]

I am not an paleontologist. So I ask dumb question (to start with) and I made claims which I do not think it would stand very well and am waiting for corrections. Why is it ingenuous?

It's disingenuous because you've admitted that your question cannot be answered to your satisfaction. It strikes me that you're asking questions in an attempt to flummox rather than to learn. I hope I'm wrong, and if I am, I apologize.

This is better. The question followed is: Did this fish species develop real bone from the cartilage at later time?

Cartilage solidifies into bone via endochondral ossification, and we can see it happening even today. So it isn't hard to explain the development of bone from cartilage in the fossil record at all. In fact, the development of bone from cartilage is a great example of ontogeny recapitulating phylogeny.

I never said paleontology is not a science. You should apologize to me by stuck it into my mouth.

I will not apologize because, whether you realize it or not, you are advocating that palaeontology is not a science. You've said that palaeontology is purely descriptive and that it does not make testable predictions. If this were true, palaeontology would indeed NOT be a science. But you're wrong, and it is. I'll show you why...

I did say paleontologist makes "suggestions" (less than "prediction"). However, I don't think any paleontological prediction is "testable". Please give me your best example on how does one "test" the validity of a paleontological prediction other than just trying to dig out more fossils. That is why I said that paleontology is simply the discovery and the analysis of data, but lack of prediction/varification process. It is simply the nature of the study.

Predictions are made and tested every day in palaeontology. The act of creating a cladogram ("family tree") makes predictions that can be tested when more fossils are found. Cladograms can also help us to predict when and where common ancestors might be found, such as Darwin's prediction that the common human ancestor would be found in Africa (and has since come to fruition). We can make predictions in palaeoecology, too. Right now I am studying a horizon of rock that yields dozens of sympatric, herbivorous dinosaur species. These dinosaurs were living side-by-side and competing for the same plant food. I can therefore predict that these dinosaurs likely partitioned the herbivore niche by feeding on different types of plants (as we see in the savannah today), and that these differences ought to manifest themselves in the dental microwear (microscopic pits and scratches left on the teeth as a result of feeding) of the animals. And as my preliminary research results have shown, my predictions are being confirmed. This is just one example of many such predictions being tested in the field. Palaeontology is indeed a science in every sense of the word.

 

[juvenissun]

My favorite example is ring species. And here's a good explanation: http://www.actionbioscience.org/evolution/irwin.html

For the ring species example, my first question is: What is the population distribution on the two distinct species and all the significant intermediate variations? In other words, is the distinctive species more abundant or is the intermediate variations more abundant? If you take the two dictinctive species as two end members of all population, how does the population curve look like?

If the identificaiton on the variation is based on the comparison of DNA sequence, then it would be a big job to answer my questin and I don't think there existed such a work.

The significance of this question is: assume both species in the ring and all the intermediate variations extincted and some of them get preserved as fossils. And let's assume we still could tell the DNA differences on these fossils (this is a big IF). Then would that mean the "transitional" fossil should NOT be so rare?

Based on the ring species description, in the ring area, there is only ONE locality where the two distinctive species coexist. That would suggest the population of the two distinctive species is, in fact, small in quantity. As a result, if chance are equal in the fossilization, we should see MORE transitional fossils than fossils of distinctive species.

How would you then make a link between the discovery of ring species with the statistics of fossil record?

 

[juvenissun]

The ring species shernren referred to are a good place to start.

You might like to follow that with this execise (for high school students) in tracing the evolution of a group of lizard species in the Canary Islands.

http://www.ucmp.berkeley.edu/fosrec/Filson.html

My first question is: how did these lizards spread across the water? Are they able to swim across the water among islands? Either they do or they don't, we can see the follow up problem on their population distribution could be sticky.

 

[juvenissun]

I will not apologize because, whether you realize it or not, you are advocating that palaeontology is not a science. You've said that palaeontology is purely descriptive and that it does not make testable predictions. If this were true, palaeontology would indeed NOT be a science. But you're wrong, and it is. I'll show you why...

OK, I see you are using a different definition of science.

Right now I am studying a horizon of rock that yields dozens of sympatric, herbivorous dinosaur species. These dinosaurs were living side-by-side and competing for the same plant food. I can therefore predict that these dinosaurs likely partitioned the herbivore niche by feeding on different types of plants (as we see in the savannah today), and that these differences ought to manifest themselves in the dental microwear (microscopic pits and scratches left on the teeth as a result of feeding) of the animals. And as my preliminary research results have shown, my predictions are being confirmed. This is just one example of many such predictions being tested in the field. Palaeontology is indeed a science in every sense of the word.

Interesting. I think your "prediction" could be too broad. Special texture on teeth could be made simply by taking ONE special plant, while the species could still share a large quantity of other plants with other species. Even it is possible that the special tooth mark could be made by a special part of a plant that other dinos do not care to eat. For example, could a particular dino be a root eater rather than a leave eater? So the "niche" hypothesis could be a very shaky one (please do not be discouraged. It would still be an acceptable study). In order to make a better argument, you would need to correlate the teeth textures with the type of plants. Are you doing that? It could be a hard job because you may not have the plant fossils in the same formation. Also, how would you prove some of the species are not omnivore? They do not have to eat a lot of meat. Just an occasional chew on bone or something hard would create a dominant mark on the teeth. How do you know some dinos do not chew rocks to help on their digestion? On this line, you may also elaborate that some prefer to chew silt, some chew sand, and some chew clay. They would all have different marks left on their teeth.

Poor paleontologist. A lot of work, but based on very simply logic and have to deal with a lot of variables. The study method is very scientific. But the nature of study can hardly be called a good science.

 

[Deamiter]

My first question is: how did these lizards spread across the water? Are they able to swim across the water among islands? Either they do or they don't, we can see the follow up problem on their population distribution could be sticky.

My first suggestion: try reading the article before criticizing it. Here's part of a paragraph on the page linked

The development of ecosystems on volcanic islands is somewhat unpredictable. However, ecological succession does occur first with pioneer organisms that gradually alter the environment until a stable climax community is established. What is unpredictable is what plant and animal species will colonize these new environments. Much of this is left to climate, proximity to other land masses, and of course, chance. This investigation deals with three species of lizards of the genus Gallotia, and within one of these species, Gallotia galloti, four separate island populations. The arrival of the Gallotia lizards was probably by rafting (See Map 1). Rafts of natural vegetation are often washed out to sea when high river levels cause river banks to collapse, carrying away both plants and clinging animals. Oceanic currents in this region vary with the seasons. Colonization by airborne organisms, such as insects and birds, usually occurs during storms. In any case, there are some general principles of island colonization:

1) The closer the island to another land mass, the higher the probability of colonization.
2) The older the island, the more likely it will be colonized.
3) The larger the island, the more species are likely to be established.
4) Geographic isolation reduces gene flow between populations.
5) Over time, colonial populations become genetically divergent from their parent population due to natural selection, mutation, and/or genetic drift.

 

[gluadys]

My first question is: how did these lizards spread across the water? Are they able to swim across the water among islands? Either they do or they don't, we can see the follow up problem on their population distribution could be sticky.

As Deamiter said, read the article.

Also note that the exercise is based on real-life facts. These lizards are real, and they are really on the islands and really distributed as indicated. These are all direct observations.

How they got there is an interesting question, but the fact is that they are there. You can't wave them away by saying they couldn't get to the islands, because they are already on the islands.

 

[juvenissun]

My first question is: how did these lizards spread across the water? Are they able to swim across the water among islands?

So, I guess the answer to my first question is that these lizards DO NOT swim. I saw some on the Galapagos Islands that they not only swim, but they could dive.

Most of the "explanations" in the article are nothing but idealized assumptions. The raft idea reminds me the movie of "cast away". It is a movie after all. I could propose that hurricane blew those lizards around and some of them just landed on other islands. You would say: it is possible. Well, that is how good some of the paleontological assumptions are. Given enough hurricanes, lizards and long enough time, one lizard would eventually go somewhere. But it would also probably die soon or is already dead.

The next question will come soon. Yes, we are going to deal with the fact, they do exist on the islands no matter what is their origin.

 

[Deamiter]

So, I guess the answer to my first question is that these lizards DO NOT swim. I saw some on the Galapagos Islands that they not only swim, but they could dive.

t
Again, read the article. It doesn't really matter if the lizards could swim because the islands are hundreds of kilometers from shore.

Most of the "explanations" in the article are nothing but idealized assumptions. The raft idea reminds me the movie of "cast away". It is a movie after all. I could propose that hurricane blew those lizards around and some of them just landed on other islands. You would say: it is possible. Well, that is how good some of the paleontological assumptions are. Given enough hurricanes, lizards and long enough time, one lizard would eventually go somewhere. But it would also probably die soon or is already dead.

These are not assumptions (it is not assumed that the lizards floated across on rafts) and it's also not idealized. Similar rafts have been repeatedly observed so it's not just a wild guess.

You seem to want to dismiss anything that wasn't directly observed as a wild guess. Honestly, do you have a better explanation that is based on observation or are you just throwing spaghetti again? Incidentally hurricanes do transfer many species among islands (though it would be silly to propose such a thing here because hurricanes don't hit these islands!) but it's usually hardier species like insects or seeds.

 

[shernren]

For the ring species example, my first question is: What is the population distribution on the two distinct species and all the significant intermediate variations? In other words, is the distinctive species more abundant or is the intermediate variations more abundant? If you take the two dictinctive species as two end members of all population, how does the population curve look like?

If the identificaiton on the variation is based on the comparison of DNA sequence, then it would be a big job to answer my questin and I don't think there existed such a work.

I'm not sure what your last question means, maybe you could give me the answer you expect? As to the first question, I'm not sure either, but I don't see why this would be significant to the observed (quasi-)speciation there. The point is that populational characteristics diverge to meet their environmental characteristics. We're talking about present populations, which can be observed in situ to be adapted to their environmental pockets and hence have diverged.

The significance of this question is: assume both species in the ring and all the intermediate variations extincted and some of them get preserved as fossils. And let's assume we still could tell the DNA differences on these fossils (this is a big IF). Then would that mean the "transitional" fossil should NOT be so rare?

Fossils are rare, fullstop. (And significantly, the rare places where rich fossil abundances do exist are frequently not associated with flood-type deposits.) The area over which a species roams may not be directly correlated to how many fossils you can find of it, since fossilization happens essentially by random chance.

Based on the ring species description, in the ring area, there is only ONE locality where the two distinctive species coexist. That would suggest the population of the two distinctive species is, in fact, small in quantity. As a result, if chance are equal in the fossilization, we should see MORE transitional fossils than fossils of distinctive species.

How would you then make a link between the discovery of ring species with the statistics of fossil record?

Maybe you've slightly misunderstood the situation. It sounds like you're proposing:

BBB
B||B
B||B
B||B
B||B
AC

(where || is the separation) It seems that to you the bulk of the transitional forms are the same on both sides of the boundary. This isn't true; the actual situation looks more like:

AAA
B'||C'
B''||C''
B'''||C'''
B''''||C''''
B'''''C'''''

where the little inverted commas denote further differentiation. The entire concept is that the species don't stay the same as their range extends down. As the range extends down on two different environments, the species changes in two different ways along the gradients to give you the final ring species. Evolution in action.

 

[Mallon]

Oh, juvenissun. If only you were as critical of young earth creationism are you are of evolutionary science.

OK, I see you are using a different definition of science.

I am using the definition of science agreed upon by the vast majority of scientists since the inception of the scientific method. This definition is espoused by the various societies to which I belong, and if I did not abide by it, I would not be allowed to publish in their journals or present at their meetings.

Interesting. I think your "prediction" could be too broad. Special texture on teeth could be made simply by taking ONE special plant, while the species could still share a large quantity of other plants with other species. Even it is possible that the special tooth mark could be made by a special part of a plant that other dinos do not care to eat. For example, could a particular dino be a root eater rather than a leave eater? So the "niche" hypothesis could be a very shaky one (please do not be discouraged. It would still be an acceptable study). In order to make a better argument, you would need to correlate the teeth textures with the type of plants. Are you doing that? It could be a hard job because you may not have the plant fossils in the same formation. Also, how would you prove some of the species are not omnivore? They do not have to eat a lot of meat. Just an occasional chew on bone or something hard would create a dominant mark on the teeth. How do you know some dinos do not chew rocks to help on their digestion? On this line, you may also elaborate that some prefer to chew silt, some chew sand, and some chew clay. They would all have different marks left on their teeth.

Poor paleontologist. A lot of work, but based on very simply logic and have to deal with a lot of variables. The study method is very scientific. But the nature of study can hardly be called a good science.

Thanks for your pity, juvenissun, but it is unwarranted. This being my PhD project, rest assured that I have done my homework so as not to waste the next 4-5 years of my life. Again, you're so quick to criticize my work when you do not even know what it is I am doing! My thesis proposal is 20 pages long and you think you can tear it to pieces after only reading the first two sentences!
To address your concerns, though, regardless of whether these herbivorous dinosaur species were feeding on different plants or different parts of the same plant, that is still niche partitioning. The animals are still reducing competition via differential usage of resources. Even the amount of grit ingested, as you suggest, can give an indication of diet because low-feeding grazers will inevitably ingest more grit than high-feeding browsers. Moreover, the ingestion of stomach stones (gastroliths) is of little concern to me because (1) fossil finds suggest the herbivores of Late Cretaceous North America did not ingest them, and (2) animals that do ingest gastroliths do not normally chew on them first. Nor am I concerned about the likelihood that these dinosaurs may have eaten meat because there is absolutely nothing to suggest they did. Their tooth/jaw morphology, fossilized dung, and fossilized stomach contents all attest to the herbivorous diet of these dinosaurs.
And lastly, yes I am studying the palaeobotany of the area as well in order to get a better understanding as to what type of foodstuffs were available to the herbivores.
Hopefully now I have convinced you that I am doing "good science," though it is my project committee, supervisor, and scholarship committees that I must first convince. And they're all behind me so far!

 

[gluadys]

So, I guess the answer to my first question is that these lizards DO NOT swim.

No it is not. I did not say the lizards do not swim. The article does not say the lizards do not swim.

Note that I am also not saying that the lizards do swim either. The article simply does not mention whether or not they swim.

Don't turn silence into an answer.

Most of the "explanations" in the article are nothing but idealized assumptions. The raft idea reminds me the movie of "cast away". It is a movie after all. I could propose that hurricane blew those lizards around and some of them just landed on other islands. You would say: it is possible.

The fact is that we have no record of how the lizards arrived. The suggestions made are possibilities, nothing more. The important point is whether they are reasonable possibilities. Can you demonstrate that they are not reasonable possibilities?

(PS if you believe in a global flood, you can hardly deny the possibility of floating on vegetation rafts since this is so often invoked as a way for some animals to have survived the flood. If animals can survive for a year on such rafts, why not for the few weeks it would take to float from the mainland to the islands?)

The next question will come soon. Yes, we are going to deal with the fact, they do exist on the islands no matter what is their origin.

Looking forward to it.

 

[juvenissun]

the actual situation looks more like:

AAA
B'||C'
B''||C''
B'''||C'''
B''''||C''''
B'''''C'''''

My question was simple. Take your illustration to explain it:

There are B', B'' ... etc. So, which one is used to define species B? And what is the population of each B derivation?

No matter which one you choose to define the B species, the population of other B derivations MUST be significantly more than that of B. So, if all Bs are subject to fossilization, why don't we see more B derivations, but only a bunch of B?

Notice that in the ring species, all Bs are coexisting at the same time. And the same argument applies to species C.

 

[juvenissun]

I am using the definition of science agreed upon by the vast majority of scientists since the inception of the scientific method. This definition is espoused by the various societies to which I belong, and if I did not abide by it, I would not be allowed to publish in their journals or present at their meetings.

I think you might need to be exposed to more courses of physics or chemistry. I do not have to argue with you on the definition of science. You just try to commnicate with one of your friends who is majored in either physics or chemistry. And you will find the disagreement on the definition.

My thesis proposal is 20 pages long and you think you can tear it to pieces after only reading the first two sentences!

No need to be sarcastic. I was just respond to what you presented. If you gave me all the 20 pages, I will work the same way on each page.

To address your concerns, though, regardless of whether these herbivorous dinosaur species were feeding on different plants or different parts of the same plant, that is still niche partitioning. The animals are still reducing competition via differential usage of resources. Even the amount of grit ingested, as you suggest, can give an indication of diet because low-feeding grazers will inevitably ingest more grit than high-feeding browsers. Moreover, the ingestion of stomach stones (gastroliths) is of little concern to me because (1) fossil finds suggest the herbivores of Late Cretaceous North America did not ingest them, and (2) animals that do ingest gastroliths do not normally chew on them first. Nor am I concerned about the likelihood that these dinosaurs may have eaten meat because there is absolutely nothing to suggest they did. Their tooth/jaw morphology, fossilized dung, and fossilized stomach contents all attest to the herbivorous diet of these dinosaurs.

Sounds very good. However, what you said would be more than a numbers of Ph.D.'s work even to the research on a modern species. Needless to say on the case of dinosaurs, which even samples are hard to get.

Hopefully now I have convinced you that I am doing "good science," though it is my project committee, supervisor, and scholarship committees that I must first convince. And they're all behind me so far!

I never doubt you are doing a good scientific "exercise". I am just arguing that your type of work could never be good enough to argue against creationism, because the whole thing is full of speculations (you may say they are higher quality speculations). I am not saying you are wrong to speculate. I am saying that is the best anyone of us could do. The science is just not good enough to be used to against the Scripture.

As far as your committee members, except your advisor, all other guys are your foes, but I am your friend. I won't save the hardest question for the moment of your defence.

 

[grimbly]

I think you might need to be exposed to more courses of physics or chemistry. I do not have to argue with you on the definition of science. You just try to commnicate with one of your friends who is majored in either physics or chemistry. And you will find the disagreement on the definition.

snip

Erm sorry, but as somebody that did chemistry for 30 years, I have to agree with Mallon. Yep, what he's doing is classical science by any definition that I've ever seen . So if you have a new definition of science I for one would like to see it.

 

[Mallon]

I think you might need to be exposed to more courses of physics or chemistry. I do not have to argue with you on the definition of science. You just try to commnicate with one of your friends who is majored in either physics or chemistry. And you will find the disagreement on the definition.

Please just come out and say it, juvenissun: What is unscientific about palaeontology in particular?

However, what you said would be more than a numbers of Ph.D.'s work even to the research on a modern species. Needless to say on the case of dinosaurs, which even samples are hard to get.

Thanks for your concern, but I have that taken care of. I am working in one of the most fossiliferous formations in the world.

I never doubt you are doing a good scientific "exercise". I am just arguing that your type of work could never be good enough to argue against creationism, because the whole thing is full of speculations (you may say they are higher quality speculations).

I am not doing this work in an attempt to combat creationism. I am doing it to earn my doctorate. Regardless, the fauna preserved in the badlands of Alberta argue strongly against a global flood scenario.

 

[juvenissun]

Can you demonstrate that they are not reasonable possibilities?
(PS if you believe in a global flood, you can hardly deny the possibility of floating on vegetation rafts since this is so often invoked as a way for some animals to have survived the flood. If animals can survive for a year on such rafts, why not for the few weeks it would take to float from the mainland to the islands?)

No. I can not. But that is the basic issue of evolution. Namely, given enough time, everything is possible. Statistically, it might be true. But for a reason unknown to me yet, I just do not believe in it.

Well, that is a good start on my next question. I wonder how fast, or what is the rate of the spiciation in this particular case. I am afraid you are going to tell me again that this question is not in the context of this study. However, I feel it might be. Notice the webpage spent some paragraphs on the ages of the islands. Does that piece of data have anything to do with the spiciation? Does that imply that lizard "jumped (floated?)" to the new island AFTER the island was formed? If it does, then the age of the island would provide a minimum time needed for the spiciation.

IF, the age of the island is related to the spiciation, then would some of the suggested phylogenic trees become impossible? (lizard is there before the island was)

 

[juvenissun]

Erm sorry, but as somebody that did chemistry for 30 years, I have to agree with Mallon. Yep, what he's doing is classical science by any definition that I've ever seen . So if you have a new definition of science I for one would like to see it.

OK, As a geologist, I was ridiculed often my physcist friends. They usually tittered me by saying: "... according to "your" science...". Well, I admit, my science is not as good as theirs.

A rigorous definition of science knowledge to me is "repeatable" knowledge. Many branches of geosciences are not in this category. We may say whatever we feel right to say based on our study. But even ourselves do not really believe it, because what we studied only happened once and could not be reproduced. Present is the key to the past is only an idea, not a scientific equatioin.

 

[Jadis40]

I should probably just ignore him, because my anger is getting the better of me. I may not be a strong believer atm, but I get deeply offended when people like him condemn other Christians to Hell because they accept evolution and an old universe.

Remember that a mortal fellow human being is not your judge, jury, and executioner, even if we hold differing viewpoints.

YECs and TEs alike ARE NOT saved by believing a literal interpretation of all of scripture, but rather by believing in the sacrifice that Jesus Christ made of Himself on the mount of Calvary to save all of us who profess a belief in Him, and who try to live a life worthy of His calling. I recognize that the Old Testament pointed towards Christ, but as Paul states in Hebrews 10 the Feasts and other regulations of the Temple were just a mere shadow of the true reality.

I fully recognize that we're all sinners, saved by the grace of God alone.

To state this again: I believe that God created the heavens and the earth, because the universe is not self-existent. I recognized that fact a long time ago. I just have a differing opinion based on the evidence that science has brought to the table that formation of the universe, galaxies and solar system was over a course of billions of years.

 

[grimbly]

OK, As a geologist, I was ridiculed often my physcist friends. They usually tittered me by saying: "... according to "your" science...". Well, I admit, my science is not as good as theirs.

A rigorous definition of science knowledge to me is "repeatable" knowledge. Many branches of geosciences are not in this category. We may say whatever we feel right to say based on our study. But even ourselves do not really believe it, because what we studied only happened once and could not be reproduced. Present is the key to the past is only an idea, not a scientific equatioin.

pfft physicist, Heck my physicist friends used to call me a "physicist wannabe who couldn't hack the math",

Of course when they wanted a new sample of material to test, they'd come groveling into my lab singing a slightly different tune...but that's another story!

Now as to repeatability... It's nice in principle but sometimes the universe just won't comply. A stellar astrophysicists studying coronal mass ejection doesn't get a chance to call Aldrich and order up a dozen class G stars (like our sun) and bring them into the lab. He, like geologists and paleontologists, has to work with what the universe makes available. Try telling him that he's not doing science!!
Heck, it's a lot tougher than what a bench chemist or physicist has to go through, at least we sometimes get to control our environments but it is no less science than what happens in an Erlenmeyer flask. It's just tougher to separate the noise from the signal. Quite frankly, I'm in awe about how much information they (being geologists/paleontologist) can ferret out of this ancient planet.

What's important is not that an event is repeatable, but rather that the measurements detailing the event(s) are capable of being duplicated and show statistical significance. In this regard, paleontology and geology pass with flying colors.