Transitional Fossils Show Evolution in Process

We often see complaints or comments about the absence of fossil evidence for transitions in evolution. This usually comes in two parts:(1) There are no transitional fossils PRATT CC200

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There are no transitional fossils. Evolution predicts a continuum between each fossil organism and its ancestors. ...

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Often this is due to a misunderstanding of what "transitional" means in evolutionary biology:Transitional fossil - Wikipedia

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Transitional fossils (popularly termed missing links) are the fossilized remains of intermediary forms of life that illustrate an evolutionary transition. They can be identified by their retention of certain primitive (plesiomorphic) traits in comparison with their more derived relatives, as they are defined in the study of cladistics. Numerous examples exist, including those of primates and early humans.

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According to modern evolutionary theory, all populations of organisms are in transition. Therefore, a "transitional form" is a human construct of a selected form that vividly represents a particular evolutionary stage, as recognized in hindsight. Contemporary "transitional" forms may be called "living fossils", but on a cladogram representing the historical divergences of life-forms, a "transitional fossil" will represent an organism near the point where individual lineages (clades) diverge.

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Thus all fossils that show intermediate characteristics between ancestral forms and descendant forms are by definition transitional. Thus whenever we see a clear lineage of fossils from an ancestral form (plesiomorphic) to derived descendant form (apomorphic), and thus they are transitional fossils.Transitional fossils will be intermediate in form between ancestral forms and descendant forms, and they will share some, but not all, traits with both ancestors and descendants, and some traits shared by ancestors, the transitional fossil and descendants may themselves be shown in intermediate stages of development, between the ancestral and descendant forms of the traits.(2) There should be billions of transitional fossils PRATT CC200.1

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Given all the species that exist and have existed, there should be billions of transitional fossils in the fossil record; we should have found tens of thousands at least.

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A recent example of this misunderstanding was presented by Kaichos Man on An ongoing report on S366:Evolution Message 19: This thread is intended to discuss and answer this issue.Enjoy.ps - I will also add 3 responses as subthreads, which will cover my initial response at Message 20, so please let me complete those before promotion.Edited by Admin, : Fix rendering.

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In the post that inspired this thread Kaichos Man claimed (Message 19): This, of course is the hoary old "absence of evidence is evidence of absence" logical fallacy.The complete absence of fossil evidence for the Coelacanth between the end of the Cretaceous period and modern day clearly proves that these fish did not exist between then and now ....Clearly this statement is false when the Coelacanths are living organisms in the modern world.Other logical fallacies are the argument from ignorance (there are no transitional fossils) and the argument from incredulity (we should be up to our necks in transitional fossils).Logical fallacies are invalid arguments.Enjoy.

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In the post that inspired this thread Kaichos Man claimed (Message 19): There are many examples of transitional fossils, and I will discuss two of these as they apply at the species level and they show precisely the "tiny dawinian step" involved in the process of speciation.(1) Foramiinifera: Evolution at Sea
Complete Fossil Record from the Ocean Upholds Darwins Gradualism

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Tony Arnold and Bill Parker compiled what may be the largest, most complete set of data on the evolutionary history of any group of organisms, marine or otherwise. The two scientists amassed something that their land-based colleagues only dreamed about: An intact fossil record with no missing links.

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"It's all here--a virtually complete evolutionary record," says Arnold. "There are other good examples, but this is by far the best. We're seeing the whole picture of how this group of organisms has changed throughout most of its existence on Earth."

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The organism that Arnold and Parker study is a single-celled, microscopic animal belonging to the Foraminiferida, an order of hard-shelled, planktonic marine protozoans. Often shortened to "forams," the name comes from the Latin word foramen, or "opening." The organisms can be likened to amoebas wearing shells, with perforations through which their protoplasm extends. The foram shell shapes range from plain to bizarre.
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"There's a nifty passage in Darwin," says Arnold, "in which he descirbes the fossil record as a library with only a few books, and each book has only a few chapters. The chapters have only a few words, and the words are missing letters."

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"Well, in this case, we've got a relatively complete library," says Arnold. "The 'books' are in excellent shape. You can see every page, every word."

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As he speaks, Arnold shows a series of microphotographs, depicting the evolutionary change wrought on a single foram species. "This is the same organism, as it existed through 500,000 years," he says. "We've got hundreds of examples like this, complete life and evolutionary histories for dozens of species."

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About 330 species of living and extinct planktonic forams have been classified so far. After thorough examinations of marine sediments collected from around the world, micropaleontologists now suspect these are just about all the free-floating forams that ever existed.

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The species collection also is exceptionally well-preserved, which accounts largely for the excitement shared by Parker and Arnold. "Most fossils, particularly those of the vertebrates, are fragmented--just odds and ends," says Parker. "But these fossils are almost perfectly preserved, despite being millions of years old."
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Darwin termed the process gradualism, a theory that invokes the slow accumulation of small evolutionary changes over a large period of time, as a result of the pressures of natural selection. What Arnold and Parker found is almost a textbook example of gradualism at work.

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We've literally seen hundreds of speciation events," syas Arnold. "This allows us to check for patterns, to determine what exactly is going on. We can quickly tell whether something is a recurring phenomenon--a pattern--or whether it's just an anomally. This way, we cannot only look for the same things that have been observed in living organisms, but we can see just how often these things really happen in the environment over an enormous period of time.

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Not just transitional fossils between one species to the next, but the whole pattern of this foraminifera phylum laid out in detail.(2) Pelycodus: A Smooth Fossil Transition: Pelycodus, a primate

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Pelycodus was a tree-dwelling primate that looked much like a modern lemur. The skull shown is probably 7.5 centimeters long.

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The numbers down the left hand side indicate the depth (in feet) at which each group of fossils was found. As is usual in geology, the diagram gives the data for the deepest (oldest) fossils at the bottom, and the upper (youngest) fossils at the top. The diagram covers about five million years.

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The numbers across the bottom are a measure of body size. Each horizontal line shows the range of sizes that were found at that depth. The dark part of each line shows the average value, and the standard deviation around the average.

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The dashed lines show the overall trend. The species at the bottom is Pelycodus ralstoni, but at the top we find two species, Notharctus nunienus and Notharctus venticolus. The two species later became even more distinct, and the descendants of nunienus are now labeled as genus Smilodectes instead of genus Notharctus.

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As you look from bottom to top, you will see that each group has some overlap with what came before. There are no major breaks or sudden jumps. And the form of the creatures was changing steadily.

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This fossil record clearly shows the "tiny dawinian steps" from generation to generation. Note that the "gaps" in time for the fossils are more than covered by the overlap in the variation within each level, each level has organisms similar to the ancestral population below it and to the descendant population above it.ConclusionClearly transitional fossils exist at the species level, fossils that clearly show the "tiny dawinian steps" from generation to generation.Enjoy.Edited by RAZD, : spling

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In the post that began this thread Kaichos Man claimed (Message 19): We can ascertain the veracity of this arguement from incredulity by comparing the fossil record for the Foraminifera, Pelycodus and the Coelacanth.As we see in the case of Foraminifera, transitional fossils between species (and higher) exist in abundance at all levels, and in this one case they cover millions of years in a continuous record. This is because the accumulation of these fossils in this location is not reliant on haphazard fossilization, random environmental factors or other things affecting the fossilization of individual organisms.Thus we see, that when there are no causes preventing the reservation of fossils, or for disrupting fossils after deposition, that there is indeed the well preserved record of evolving life year after year, generation after generation, species after species, etc etc, for millions of years.Next we look at Pelycodus and we do see gaps between the fossil layers. There are several reasons such gaps can exist:

• the organisms can migrate between areas and thus are only fossilized in one area when they die in that area,
• natural disasters that kill and cover organisms to begin the fossilization process may be relatively rare in the ecology, and
• the ecology may alternate between wet and dry, with fossils only being preserved during dry periods,
• etc.

Finally, we look at the Coelacanth. The last fossil evidence for Coelacanths is over 65 million years old:Coelacanth - Wikipedia

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Although now represented by only two known living species, as a group the coelacanths were once very successful with many genera and species that left an abundant fossil record from the Devonian to the end of the Cretaceous period, at which point they apparently suffered a nearly complete extinction. Before the living specimens were discovered, it was believed by some that the coelacanth was a "missing link" between the fish and the tetrapods. It is often claimed that the coelacanth has remained unchanged for millions of years, but, in fact, the living species and even genus are unknown from the fossil record. The most likely reason for the gap is the taxon having become extinct in shallow waters. Deep-water fossils are only rarely lifted to levels where paleontologists can recover them, making most deep-water taxa disappear from the fossil record.

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Here we have a gap in the fossil record of ~65 million years, and yet we have living Coelacanths that clearly show that the absence of fossil evidence is not evidence of absence of Coelacanths. This also shows that fossils do not have to be preserved for intermediate forms.ConclusionsWhat is clear, from comparing these three cases, is:

1. there is a significant difference in the degree of preservation of fossils between Foraminifera, Pelycodus and Coelacanths,
2. when there are no reasons for fossils not to be preserved (Foraminifera), that there are extensive fossil transitional records,
3. when there are reasons that fossils may not be preserved (Pelycodus), that there are gaps in the fossil record due to missing fossils, and
4. even when there are massive gaps in the fossil record (Coelacanths), that this does not mean that the intermediate organisms were missing, just that they did not fossilize where fossils have been discovered

Simply put, fossils do not need to exist to fill in gaps in the fossil record for intermediate forms to have existed.Enjoy.

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Hi sailorstide, welcome to the fray. Missing links - being missing - don't prove anything other than the evidence is missing.Transitional fossils - fossils intermediate in form between ancestral and descendant forms - can show the hereditary lineage by the progression of change in features over time.This can show the hereditary pattern/s of life from the first forms, whether those are creationist or evolutionary, and thus help us sort between one concept and the other to determine which is the more likely explanation. A scientific theory is based on evidence first, then deduced explanation, then testing and then revision as required to explain all the evidence (the scientific process). Thus there is more to a scientific theory than "just a theory" because there is the evidence supporting it, and the testing that validates it and tests it against reality.Evolution fits this definition of theory as a scientific theory. The evidence is the process of evolution we see in the world around us (where all known breeding populations show change in the frequency of hereditary traits from generation to generation), and in the process of speciation (where a parent population divides into two non-interbreeding daughter populations). These are both observed facts. The theory then, is that these two processes can explain the diversity of life as we know it, from the life around us, from history, from archaeology, from the fossil record and from the genetic record. The testing is every new piece of information about past life, whether genetic or fossil, which can either fit the theory or not.Creationism, as far as I can tell, is not founded on evidence, nor does it appear to do any testing of the creationist concept. Rather it seems to be predicated on the a priori assumption that creation is true. This makes it more of an hypothesis, a conjecture, an assumption, rather than a scientific theory based on evidence first, then deduced explanation, then testing and then revision as required to explain all the evidence (the scientific process).But this thread is not about the issue of what is or is not a scientific theory, so if you want to discuss this further, please start a new topic if you want to pursue this, as I'm sure this is a sufficient topic for a new thread.Go to Proposed New Topics to post new topics. I'm sure you will have plenty of takers. I am not aware of one fact that supports creationism, while I am aware of hundreds that support evolution.Perhaps you can supply us with supporting evidence for creationism? Please start a new topic if you want to pursue this, as I'm sure this is a sufficient topic for a new thread.Go to Proposed New Topics to post new topics. I'm sure you will have plenty of takers. Unfortunately for you, science is not done by popular vote, it is done by actually confronting the evidence and seeing if the theory passes or fails the tests. Thus when the original post states:

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We often see complaints or comments about the absence of fossil evidence for transitions in evolution.

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Often this is due to a misunderstanding of what "transitional" means in evolutionary biology:

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Thus all fossils that show intermediate characteristics between ancestral forms and descendant forms are by definition transitional. Thus whenever we see a clear lineage of fossils from an ancestral form (plesiomorphic) to derived descendant form (apomorphic), and thus they are transitional fossils.

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Transitional fossils will be intermediate in form between ancestral forms and descendant forms, and they will share some, but not all, traits with both ancestors and descendants, and some traits shared by ancestors, the transitional fossil and descendants may themselves be shown in intermediate stages of development, between the ancestral and descendant forms of the traits.

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This thread is intended to discuss and answer this issue.

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The intent is to discuss the evidence that shows intermediate forms in the fossil record. This is done in Message 3, where clear examples of transitional fossils are presented.The logical conclusions are (a) that transitional fossils exist, (b) they show the same kind of change in hereditary traits in breeding populations from generation to generation as we see in life around us today, and (c) they show the same kind of division of parent populations into non-interbreeding daughter populations as we see in life around us today.They are intermediate.They validate evolution and speciation as being sufficient to explain the diversity seen in the course of their fossil record.Enjoy.

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Hi Taq, love your icon\avatar. A most excellent point, and this also contrasts with the creolution concept of transformation of individual organisms so that there are half formed new features sprouting out of fossils, a cat evolving into a dog, or where new species are formed suddenly by single individuals in one single generation. Creolution claims these are part of "macroevolution", but evolution actually predicts that these type of "transformations" would NOT occur, thus evidence of them would actually be evidence against evolution. Such things are not found in the fossil record or in life around us today.Evolution predicts nested hierarchies via common descent from ancestral populations.In contrast, design (as opposed to creationism ...) would imply that good design features would be replicated, not in a nested hierarchy, but in a manner where new features would be spread across hereditary lineages. We see this repeated again and again in human artifacts and in modern design: the rear windshield wiper appeared on a (iirc) volvo stationwagon, the next year it was seen on many other makes and models, and now is almost ubiquitous on SUVs. We do not see this cross hierarchy design copy pattern in life.Design predicts non-nested hierarchies of features copied across ancestral lineages. We now, in the last 50 years, have a second method to verify the nested hierarchy through genetics. Genetics was\is probably the biggest test of evolution, for there is absolutely no reason for a nested hierarchy to appear in the genomes of organisms without common ancestry being true.We see that similar forms occur with convergent evolution, say of sugar gliders and flying squirrels: So if evolution were not true, that these organisms did not evolve from highly diverse lineages, placental and marsupial diverging long ago, then there should logically be similar DNA for the formation of similar features. Instead genetic analysis says one is placental and the other is marsupial by the nested hierarchies visible in the genetic record. The genetic record confirms the pattern of evolution found in the fossil record.If evolution were not true then there should be homologous DNA for analogous features, and this is not seen in life today. It should be noted that gaps do not disprove evolution unless it can be shown that the development of the (theoretical) descendant could not evolve from the last known (proposed) ancestor. These linkages are usually shown as dotted lines of the proposed hierarchy, based on the best morphological evidence available.We are now seeing those gaps being crossed with genetic analysis, where the homologous structure of DNA forms another system of nested hierarchies. Evolution not only predicts that nested hierarchies occur, but that the same nested hierarchies are found in genetics as are found in the fossil record.Like the double helix of DNA, the double pattern of nested hierarchies is seen in life today, entwined one with the other.Enjoy.Edited by RAZD, : copied

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Hi again sailorstide, Curiously, this has nothing to do with the existence of transitional fossils and whether or not they show evolution in process.Interestingly, there are people that are really serious about talking about the topic of this thread and the factual evidence of reality that exists, whether you believe the evidence or not.Fascinatingly, your opinion has no ability to affect reality in any way.As I noted in reply to your first post, Message 11, this topic is about transitional fossils:

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The intent is to discuss the evidence that shows intermediate forms in the fossil record. This is done in Message 3, where clear examples of transitional fossils are presented.

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The logical conclusions are (a) that transitional fossils exist, (b) they show the same kind of change in hereditary traits in breeding populations from generation to generation as we see in life around us today, and (c) they show the same kind of division of parent populations into non-interbreeding daughter populations as we see in life around us today.

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They are intermediate.

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They validate evolution and speciation as being sufficient to explain the diversity seen in the course of their fossil record.

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Now if you want to discuss transitional fossils then by all means participate in this thread.However, if you are going to provide us with the depth of your theological\philosophical comments on any other topic then please start a new thread.Go to Proposed New Topics to post new topics. Please note that there are many people that are believers in GOD and that have no problem whatsoever reconciling their belief with science in general and evolution in particular. I'm one (see signature).Thus talking about GOD is irrelevant to discussing the reality of transitional fossils, the age of the earth and the geology of the fossil record.So are you going to talk about the topic or start a new thread?Enjoy.

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AND YOU ARE STILL OFF TOPICEdited by RAZD, : subtitle

Please start a new thread to discuss this.Sailorsides comments have nada to do with the evidence for transitions in the fossil record. Replying to him only makes the off topic ramble worse.

Thanks for the reply sailorside, Sorry but the evidence is against you. Your first post was a reply to Briterican, Message 6, and Briterican was on topic, but your reply glanced at the topic and then drifted off into non-topic issues as you stated your personal belief\opinion, and replies to those non-topic issues you introduced went further off-topic, including all of your following replies.Thus if we follow the common descent of replies we find your post Message 7 at the node where they diverge from the topic.But this is relatively irrelevant if we can get back on track and discuss the evidence that transitional fossils show evolution is process. It is extraordinarily easy to diverge from topics when one uses words or phrases that start side discussions so I am not blaming you, just trying to get back on topic. Yes, that is the genetic evidence of common ancestry, evidence that links hereditary lineages in the same way that the morphological evidence in the fossil record links hereditary lineages. This is secondary evidence that the transitional fossils do indeed show evolution in process, as they confirm the pattern of common descent. Technically yes, however we don't currently have DNA of ancient fossils so this is difficult to confirm for fossils.What we do know is that DNA\RNA evidence shows a pattern of hereditary traits that can be used to develop a pattern of common descent that explains all the evidence. We also know that there is no known reason for this pattern to match and mimic the pattern determined from morphological evaluation of all the fossil evidence, unless common descent is the correct/proper/valid explanation: common descent would predict both patterns.However, genetic evidence is not relevant to the actual pattern of evolution seen in the fossil record - that evidence stands on it's own as a test of the theory of evolution and as noted in Message 11 (my first reply to you):

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The intent is to discuss the evidence that shows intermediate forms in the fossil record. This is done in Message 3, where clear examples of transitional fossils are presented.

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The logical conclusions are (a) that transitional fossils exist, (b) they show the same kind of change in hereditary traits in breeding populations from generation to generation as we see in life around us today, and (c) they show the same kind of division of parent populations into non-interbreeding daughter populations as we see in life around us today.

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They are intermediate.

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They validate evolution and speciation as being sufficient to explain the diversity seen in the course of their fossil record.

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So we do see validation for common descent and evolution in the transitional fossils that exist in the fossil record.Enjoy.Edited by RAZD, : addEdited by RAZD, : link

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Hi Kaichos Man - still reading more into information than is there? There are a couple of problems here. Notice at the right edge of your graphic there is a group labeled "planktonic" and the rest are all benthic.Your article applies to benthic forms:

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The diversity and distribution of modern benthic foraminifera has been extensively studied in order to aid the paleoecological interpretation of their fossil record.

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While Arnold and Parker studied planktonic: Evolution at Sea

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Tropical and subtropical seas around the globe abound with forams, which are divided into two general types: The free-floating, planktonic form that is uniformly small (usually less than a 50th of an inch long) and the benthic or bottom-dwelling variety that is typically much larger. The later type is perhaps best remembered by Earth-science students or by spelunkers who commonly find the fossils imbedded in cave walls. The ancient Egyptians used limestone blocks containing the large, extinct Nummulites to build the tops of some Giza pyramids.

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But it's the planktonic variety that chiefly interests Parker and Arnold. Unlike their oversized cousins, free-swimming forams are found almost everywhere in the oceans. Their fossilized skeletons, in fact, were among some of the first biological material recovered from deep ocean bottoms by scientists in the 1850s. For nearly a century, geologists have used the tiny fossils to help establish the age of sediments and to gain insight into prehistoric climates.

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So the free floating ones are not bound by the ecological constraints of their local environment the way the benthic ones are.Furthermore, your article only covers two groups of benthic forams:http://www.springerlink.com/content/83502273g54060w5

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... Here, we present two examples of the use of DNA sequences to examine the diversity of benthic foraminifera. The first case deals with molecular and morphological variations in the well-known and common calcareous genus Ammonia. The second case presents molecular diversity in the poorly documented group of monothalamous (single-chambered) foraminifera. Both examples perfectly illustrate high cryptic diversity revealed in almost all molecular studies. ...

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However, similar studies have been done on the planktonic forams with similar results of finding cryptic species.Foraminifera - Wikipedia

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Modern forams are primarily marine, although some can survive in brackish conditions.[4] A few species survive in fresh water and one even lives in damp rainforest soil. They are most commonly benthic, and about 40 morphospecies are planktonic.[1] This count may however represent only a fraction of actual diversity, since many genetically discrepant species may be morphologically indistinguishable.[5]

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[5]^ Kucera, M.; Darling, K.F. (2002). "Genetic diversity among modern planktonic foraminifer species: its effect on paleoceanographic reconstructions". Philosophical Transactions of the Royal Society of London A360 (4): 695—718.

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Where "morphospecies" are species groups defined by their morphology, while understanding that there may be one or more cryptic genetic species involved. This means there are possibly more species, but it is difficult to say because they look the same.So finally, there is the problem of what the evidence actually shows, versus what you claimed: You have it exactly backwards -- the cryptic forams were wearing the "same coats" while exhibiting greater diversity under those "coats" (tests).At worst this means that where Arnold and Parker saw some speciation events, they may have missed others due to crypsis, and this in no way invalidates the speciation events seen, nor does it invalidate the panorama of transitional forms for the planktonic forams. Classifying forams by their tests ("coats") underestimates the diversity, but does not invalidate the fossil record of change in breeding population from generation to generation.Enjoy

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Further to the previous reply, the article cited can be found here: Cryptic species of planktonic foraminifera: thier effect on paleoceanographic reconstructions, by Kucera, M., and Darling, K.F., 2002.Bits and pieces from the article:

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(abstract)Shells of planktonic foraminifera recovered from marine sediments provide a multitude of important palaeoproxies. Most of these proxies are based on the assumption that each morphospecies of planktonic foraminifera represents a genetically continuous species with a unique habitat. ... To date, 33 cryptic genetic types were found in 9 out of the 22 sequenced morphospecies of modern planktonic foraminifera. An examination of this database suggests that cryptic genetic diversity may be a prevalent pattern among modern planktonic foraminifera, but that the total number of cryptic genetic types per morphospecies is not large and that most genetic types show a non-random pattern of distribution in the oceans. ... Trials with arti cial neural networks (ANNs), the modern analogue technique and Imbrie{Kipp transfer functions showed that the splitting of G. bulloides into three genetic types resulted in substantial reduction in the prediction error rate (by 5 to 34%) and that this improvement was by far greatest in ANN trials (on average more than 20%). We conclude that such a large reduction in error rate occurred because the models resonated with a real pattern in the original data. This study indicates that genetic diversity among planktonic foraminifera may become more of a gift than malaise to palaeoproxies. If it becomes possible to distinguish these genetic types in the fossil record, the accuracy of proxies based on planktonic foraminifera will indeed substantially increase.

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Individual species of planktonic foraminifera differ substantially in environmental preferences, physiology, feeding, behaviour and reproduction (see, for example, Hemleben et al . 1989). These parameters exert direct influence on their spatial and temporal distribution in the oceans and on the shape and chemistry of their shells. Therefore, most proxies derived from planktonic foraminifera require species-specific calibration (Spero et al . 1997; Bemis et al . 2000; Bijma et al . 1998). Consequently, the recent discovery of cryptic genetic diversity in modern planktonic foraminifera (Huber et al. 1997; Darling et al . 1999, 2000; de Vargas et al . 1999, 2001) has potentially significant repercussions for such palaeoproxies. There is growing evidence that these cryptic genetic types are ecologically different (Huber et al . 1997; Darling et al . 1999, 2000; de Vargas et al . 1999, 2001; Stewart et al . 2001). This means that all palaeoceanographic proxies may have been in fact based on aggregates of ecologically distinct populations and may therefore contain significant noise, if not error (Darling et al . 2000).

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On the other hand, the discovery of this hidden diversity may help to elucidate patterns of distribution in certain modern species that could not be easily explained by assuming that these represented ecologically unique entities (see, for example, Hilbrecht 1997). It also holds great promise for improving the accuracy and reliability of foraminiferal proxies. For example, sea-surface temperature (SST) reconstruction techniques based on planktonic foraminifer species abundances seem to be limited in their precision to an average prediction error rate of ca. 1 C (Malmgren et al . 2001). ....
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Diagnosis of modern planktonic foraminifer species is based almost entirely on the morphology of their shells. Biological observations have been used mainly to validate the morphologically de ned taxa (Hemleben et al . 1989). Although a significant morphological variation has been described within these morphospecies (i.e. species whose diagnostic concept is based on morphological features), the exact significance of the observed differences has not been fully understood and the various morphotypes were treated as ecophenotypic variants (Ericson 1959; Kennett 1968a; b; Frerichs et al . 1972; Malmgren & Kennett 1972, 1976; Hecht et al . 1976).

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Recent molecular studies (Darling et al . 1999, 2000; de Vargas et al. 1999 , 2001) have demonstrated that many of the traditionally identified planktonic foraminifer species consist of complexes of genetically distinct types. All genotypes were characterized by sequencing typically 1000 base pair (bp) fragments of the SSU rRNA gene. Within each genetic type, all specimens are identical across the entire sequenced fragment. Between the genotypes, a significant number of differences can be observed (see, for example, Darling et al . 1999, 2000; de Vargas et al . 1999, 2001). This discovery allows a completely new look at the species concept in this group and reveals a new possible explanation for the large variability within traditional morphospecies.

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The genetic types are likely to represent cryptic sibling species, a commonly observed phenomenon among marine organisms (Knowlton 1993), where species level differences are not obvious from morphology alone. The term `cryptic species’ is commonly used to refer to morphologically identical forms distinguished only by genetic, physiological or behavioural differences compared with `pseudo-siblings’ or `pseudo-cryptic species’ (sensu Knowlton 1993) where a potentially high degree of underlying genetic variation is reflected only by recondite morphological alterations, often previously unnoticed or ascribed to ecophenotypic variation. In the absence of conclusive evidence that these genetic types can be differentiated on morphological grounds, we use the term `cryptic species’ to denote genetically distinct types within the traditionally recognized morphospecies of modern planktonic foraminifera.
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The compilation of all data published or otherwise presented to date (table 1, gure 1) clearly suggests that cryptic genetic diversity is a persistent pattern among modern planktonic foraminifera. Distinct genetic types have so far been recognized in nine morphospecies, but it appears likely that extensive studies will identify such genetic types in most, if not all of the traditionally recognized modern species. It is also clear that these cryptic genetic types show distinct patterns of distribution in the ocean (table 1) and that it is highly likely that they in fact represent distinct biological species.

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Although the potential benefit of the genetic diversity of planktonic foraminifera for palaeoproxies has been demonstrated more convincingly in this study, one major obstacle to the realization of this potential remains. The genetic diversity must be translated into morphological features so that the genetic types will no longer need the label `cryptic’ and it will become possible to differentiate at least some of them in the fossil record. Huber et al . (1997) and de Vargas et al . (2001) provided the rst evidence that the large `phenotypic’ morphological variability observed in modern species might indeed be linked to genetic differences. The challenge ahead is to expand these studies, including all of the known genetic types, and develop effective and useful criteria for their morphological discrimination.

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Things to note:

1. Individual species of planktonic foraminifera differ substantially in environmental preferences, physiology, feeding, behaviour and reproduction.
2. Recent discovery of cryptic genetic diversity in modern planktonic foraminifera shows that ~ 2 to 6 genetic types have previuosly been lumped into one species by morphology, creating what is called a morphospecies.
3. The genetic types likely represent cryptic sibling species, a commonly observed phenomenon among marine organisms.
4. These cryptic species also seem to differ in environmental preferences, physiology, feeding, behaviour and reproduction -- ie behave biologically as different species.
5. Some of the variation seen within the different morphospecies can be explained by the different genetic types, and this can lead to differentiating these genetic species on a morphological basis.
6. Similar differentiation may be possible in the fossil record to differentiate between sibling species by fine tuning the morphological groupings -- ie using splitter rather than lumper classifications, but still along the lines of what Arnold and Parker have already done.

None of this recent work invalidates the fossil record showing lineages of common descent with changes in morphology over time, nor does it invalidate the observed division of parent populations into reproductively isolated daughter populations, rather this new work reinforces this pattern and extends it to a finer detail in the living species. This same level of detail may not be discernible in the fossil record, yet we can assume that it exists or not, and the pattern of common descent still holds, locked in the fossils, evidence of intermediate forms between ancestral and descendants, evidence of evolution in process: forams are indeed transitional fossils, as the term is used in science.Enjoy.Edited by RAZD, : more linksEdited by RAZD, : glitch fixed

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Hi Kaichos Man, you will be pleased to know that I gave your post serious consideration. I'm going to go long on you, because you deserve it.When you first posted the question about ecophenotypes I noticed that you provided no evidence to link the term to foraminifera other than your claim. Previous experience with your claims leaves this a questionable source of authority at best. It seemed fairly obvious to me that you had, once again, willfully misinterpreted some piece of information.I notice you've changed the picture - the other one showed better the divisions of the different groups of foraminifera (remember that this is a phylum not a species), however I can still work with this new graph as it shows the major groupings of forams. There are ~13 known orders of foraminifera, with more taxon divisions below that. Parker and Arnold said that they had documented over 300 species ("Counting both living and extinct animals, about 330 species of planktonic forams have been classified so far, Arnold said."), so there are likely quite a number of extant species.Here is your previous image for reference (from your actual source):

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The Fossil Record

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Notice that the width of the bars in this graphic represent the number of families within each group, so we still are not down to the species level or even the genus level.BTW -- I'll echo Percy here: if you are going to post pictures or quote sections of articles you should provide links to your sources as part of your evidence, it's that old thing about proper credit where it is due eh?Here is the text that accompanies your current picture:

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Consider the following illustration and note that the foraminifers of today vary in morphology according to changes in ocean depth. As illustrated above, Tosk argues that morphologic variation or "sorting" within the geologic column can be based on normal ecologic distribution. Tosk goes on to argue that within a single foraminifer species, certain members may have thickly ornamented tests under normal oxygen concentrations and thin less-ornamented tests in environments where oxygen concentrations are low. Such variations that are based, not in genetics, but in environmental influences, are called "ecophenotypic" variations. Based on these ideas, Tosk theorizes about how the geologic foraminiferan data could be explained by a rapid catastrophic burial:

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Evidently Tosk is a creationist trying desperately to explain away the vast geological ages and massive data on foraminifera with a global flood and half vast imagination. You should use (a) more current resources and (b) more reliable resources. Let's continue:This latest picture shows 14 different examples of forams occupying different ecologies, and this may be where the known orders were when it was published (in 1988). Certainly we cannot assume that this picture represents species or genera or even families of forams, as too few are shown.The second reason I thought you were blowing smoke, was that I had not run across the term you gave in any previous reading on forams, and it was not mentioned in the article on forams in wikipedia (not that this is an authority, just a relatively current referential starting point).The third reason I thought you had it all wrong, was that the article you quoted (without source) contradicted what you said:

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The diversity and distribution of modern benthic foraminifera has been extensively studied in order to aid the paleoecological interpretation of their fossil record. Traditionally, foraminiferal species are identified based on morphological characters of their organic, agglutinated or calcareous tests. Recently, however, new molecular techniques based on analysis of DNA sequences have been introduced to study the genetic variation in foraminifera. Although the number of species for which DNA sequence data exist is still very limited, it appears that morphology-based studies largely underestimated foraminiferal diversity.(Pawlowski and Holzmann, 2007) Emphasis added.

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Percy found the link to the abstract you quoted from: And here is the whole abstract:

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Diversity and geographic distribution of benthic foraminifera: a molecular perspective
Jan Pawlowski1 and Maria Holzmann2
(1) Department of Zoology and Animal Biology, University of Geneva, Geneva, 1211, Switzerland
(2) Department of Palaeontology, University of Vienna, Althanstrasse 14, Vienna, 1090, Austria
Received: 19 March 2007 Accepted: 22 June 2007 Published online: 16 October 2007

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Abstract The diversity and distribution of modern benthic foraminifera has been extensively studied in order to aid the paleoecological interpretation of their fossil record. Traditionally, foraminiferal species are identified based on morphological characters of their organic, agglutinated or calcareous tests. Recently, however, new molecular techniques based on analysis of DNA sequences have been introduced to study the genetic variation in foraminifera. Although the number of species for which DNA sequence data exist is still very limited, it appears that morphology-based studies largely underestimated foraminiferal diversity. Here, we present two examples of the use of DNA sequences to examine the diversity of benthic foraminifera. The first case deals with molecular and morphological variations in the well-known and common calcareous genus Ammonia. The second case presents molecular diversity in the poorly documented group of monothalamous (single-chambered) foraminifera. Both examples perfectly illustrate high cryptic diversity revealed in almost all molecular studies. Molecular results also confirm that the majority of foraminiferal species have a restricted geographic distribution and that globally distributed species are rare. This is in opposition to the theory that biogeography has no impact on the diversity of small-sized eukaryotes. At least in the case of foraminifera, size does not seem to have a main impact on dispersal capacities. However, the factors responsible for the dispersal of foraminiferal species and the extension of their geographic ranges remain largely unknown.

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There are a couple of things to note here:

1. Ammonia is a genus, still not a species (one we will come back to later),
2. the second group is poorly documented due to the morphological similarities (especially with them all being single chambered), still not a single species,
3. both show "high cryptic diversity",
4. morphology-based studies (eg Parker and Arnold) largely underestimated foraminiferal diversity, and finally
5. the molecular DNA studies are new as of 2007 (rather than 1988).

Now, in general, when biologists talk about variations within a species they use the term variety. Several different varieties can exist within a single species, and it is common in many species to have distinctive varieties. To have ecophenotypic variants you would need to have distinctly different varieties within a genetic species.Conversely, when biologists generally talk about differences between species they talk about diversity, when speciation occurs the parent population diversifies into two distinct species.Cryptic means that different species look alike:Species complex - Wikipedia

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In biology, a cryptic species complex is a group of species which satisfy the biological definition of species; that is, they are reproductively isolated from each other, but their morphology is very similar (in some cases virtually identical).

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They are typically very close relatives and in many cases cannot be easily distinguished by molecular phylogenetic studies either:

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... italics for emphasis.So when the paper says that both examples "perfectly illustrate high cryptic diversity revealed in almost all molecular studies" they specifically mean that there are cryptic species that look very similar but that they are genetically distinct.They may be (likely are) closely related (especially given that Ammonia is a genus), but they are not variations within a single species.Likewise when they say that "morphology-based studies largely underestimated foraminiferal diversity" they means that there are more species than is readily apparent from just looking at the morphology due to the cryptic species looking so similar. Entirely the opposite of what your creationist website tries to pretend.Now I though I made this point clear when I posted the quote from the wikipedia article on forams (that mentions morphospecies but does not mention ecophenotypes): Notice that when we talk about modern planktonic forams, that there are some 40 morphospecies, 40 groups that are morphologically different.Now I though I drove this point home in the next post when I provided you with a second reference, this one on planktonic foraminifera, similar to the ones studied by Parker and Arnold, that ALSO talked about morphospecies: Notice that all the references to classification of forams as "ecophenotypic variants" are dated 1976 or earlier. Before Parker and Arnold (so they would be aware of this possibility) and before DNA sequencing for genetic analysis.Notice that this paper shows that what appeared to be "ecophenotypic variants" is now, by genetic analysis, seen as the genetic variation within the different morphospecies explained by the different genetic types, species classifications based on DNA instead.Now we come to your recent post. First, you will note that I did not introduce morphospecies, I provided the evidence from scientific studies of actual forams by scientists who classified them as morphospecies, and went on to show that the articles were indeed talking about morphospecies and not ecophenotypes. These articles show that you had it backwards. And again, you provide no reference of actual science done on forams to substantiate this claim.Please note that nowhere in my post did I mention "cryptic genetic variation" -- that this is YOUR misrepresentation of the argument against you. I mentioned cryptic species (because the articles talk about cryptic species), and I mentioned cryptic genetic diversity (reference above to terminology). So I went looking for scientific articles on forams and ecophenotypes to see what I could find.

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Just a moment...
DOI: 10.1306/A1ADD99E-0DFE-11D7-8641000102C1865D
GCAGS Transactions
Volume 28 (1978)

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ABSTRACT

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The shallow, brackish-water environment of San Antonio Bay, Texas, supports a benthic foraminiferal fauna whose major constituents are widespread around the margin of the Gulf of Mexico, the southern Atlantic Coast of the U. S., the West Indies, and in low latitudes along the Atlantic and Pacific Coasts of South America. Several species of Ammotium, Ammonia, and Elphidium have been recognized by most authors as the dominant taxa in these estuaries. A scanning electron microscope (SEM) analysis of the exterior test morphology in five species from San Antonio Bay (Ammonia parkinsoniana, Elphidium gunteri, E. galvestonense, Palmerinella palmerae, and Ammotium salsum) reveals that two distinct phenotypes are present within each species. Each phenotype of a given pair is linked to the other by transitional phenotypes whose taxobases vary clinally. The distribution of each member of a phenotypic pair is directly correlated with the distribution of salinity and temperature in the bay. Thus, the paired phenotypes are ecophenotypes. Smaller, thinly calcified ecophenotypes having fewer chambers characterize environments that are near optimum for the respective calcareous species; the agglutinant species A. salsum is small, thin, and made of fine grains, in near optimum environments. Larger, thickly calcified ecophenotypes having more numerous chambers are characteristic of environments that approach minimum tolerances of each calcareous species; A. salsum becomes larger, more inflated, and composed of larger grains in near-minimum environments. Field and laboratory evidence demonstrates that this paired ecophenotypy is caused by contrasting results of delayed reproductive maturation in minimum environments, versus accelerated maturation in optimum environments. Longer growth periods produce larger, thickly calcified tests; shorter growth periods produce smaller, thinly calcified tests. The phenomenon of paired ecophenotypy, though rarely mentioned, has persisted in low-latitude estuaries since at least the early Miocene, as demonstrated by a review of published records. Recognition of this characteristic among the cited and other species (living and fossil) will clarify much of the taxonomic and ecologic confusion that has arisen from close morphologic similarity among estuarine and near-shore marine phenotypes. It also will help to provide more accurate paleoecological interpretation and correlation of marginal marine strata.

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"Failure to take into consideration the particular characteristics of a group and the nature and degree of its variation may result in the artificial separation of many 'morphological' species on the basis of minor phenotypic variations, even when the population at a given locality or stratigraphic level contains the complete series of gradations between two or more of these. As these individuals represent minor portions of a continuous population, regardless of the method of reproduction, they represent a single biological species, for which subdivision is unwarranted."

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(Helen Tappan, 1976, P. 304)

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Note (1) that this is 1978, and (2) that these forams involved ("Ammotium, Ammonia, and Elphidium") are three benthic genera, one of which Ammonia is specifically referred to in the article on benthic forams that showed cryptic genetic diversity instead of ecophenotypic variation.New information displaces old mistakes.

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Geology; March 1986; v. 14; no. 3; p. 218-220; DOI: 10.1130/0091-7613(1986)142.0.CO;2
1986 Geological Society of America
Late Miocene shore in northern Costa Rica: Benthic foraminiferal record
Barun K. Sen Gupta1, Luis R. Malavassi2 and Enrique Malavassi3

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1 Department of Geology, Louisiana State University, Baton Rouge, Louisiana 70803
2 Refinadora Costarricense de Petroleo S.A. (RECOPE), San Jos, Costa Rica
3 Departamento de Quimica, Universidad de Costa Rica, San Jos, Costa Rica

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In northern Costa Rica, the upper part of a volcaniclastic lithostratigraphic unit (Venado Formation) contains low-diversity benthic foraminiferal assemblages. The geologic age of these sediments is interpreted to be late Tortonian—Messinian (N17), on the basis of the 6.1 0.6 Ma K-Ar age of a younger trachyandesite and an ostracode index genus from an older unit. The benthic foraminifera, in particular two ecophenotypes of Ammonia parkinsoniana (d'Orbigny), indicate that in the late Miocene, a shallow, brackish bay existed there, the shore lying to the north and west. The bay was an extension of the Caribbean Sea, already separated from the Pacific in this part of Costa Rica.

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1986 - still old stuff, and ... Ammonia again.The other articles I found mentioned ecophenotypes because they cited the old papers as part of the history of classifying forams. One of these papers is the one I've provided in Message 36.By the time that Parker and Arnold made their morphological analysis of all the known marine planktonic forams, the idea of ecophenotypes had pretty much disappeared, and when you get to all the current articles that are based on genetic analysis we see that previous classification involving "ecophenotypic variants" were eroneous, and that the slight morphological differences were due to real genetic differences between cryptic species. No, Kaichos Man, it is not always possible to tell when you just look at the morphologies, however when you use genetic analysis and determine that there are distinct different genotypes involved you can tell, due to real genetic differences between cryptic species.This is what science has done since 1988. It has invalidated your premise that ecophenotypes are rampant through the phylum, and it has consistently shown that there are more genetic species instead -- more diversity, not less. Parker and Arnold showed what a robust morphological analysis could do to the biogeology of forams, but they underestimated the diversity of species involved.As such their morphological tree of descent from common ancestors stands, not dismembered, but stronger as it is validated by the genetic analysis of planktonic forams. The transitions and speciation events they show are still valid transitional fossils, although they may represent genera instead of species.Enjoy.ps -- thanks with providing me with another creationist hoax site (for Message 56):
The Emperor Has No Clothes - Naturalism and The Theory of Evolution
telling lies to gullible believersEdited by RAZD, : linkEdited by RAZD, : clrty

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Well Kaichos Man, what do you think? The evidence shows that whenever genetic analysis is done, that no evidence for ecophenotypic variation is found, and in it's place, several cryptic species are found that are more than adequate to explain the previous old (1976) idea that ecophenotypic variation was involved.The evidence shows that the text accompanying your second picture, the one by creationist Trosk, is false, and that the different orders of forams are not all one species. His diagram is obviously a depiction of many of the same shells as the first diagram, which represents the orders of forams, not species, and when species are genetically distinct within the genus level, any attempt to claim that orders are one species is just plain ridiculous. Trosk is a discredited charlatan, and "Sean D. Pitman M.D." is either a gullible fool, delusional, ignorant of reality, or intentionally lying (your choice). You have the opportunity to learn from his mistake.Enjoy.

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Hi again hawkes nightmare, finding your way around? You mean the example of convergent evolution that was given in Message 14: If you reply to the message with the information you are replying to with the message reply button (there's one at the bottom right of each message):

... your message is linked to the one you are replying to (adds clarity). This helps people track back to see what the previous post was about.You can also look at the way a post is formatted with the "peek" button next to it. Why?You will note that these cute little guys are not presented as intermediate fossils, but rather part of a secondary test of evolutionary theory.The fact is that skin rarely fossilizes, and so such features are hard to distinguish in the fossil record -- they may be there but not noticed as ancestral to the sugar glider or flying squirrel.What we do know from the skeletal and genetic evidence of both animals, is that they have distinctively different features and traits under the skin, and that the appearance of similarity is just that: superficial skin deep appearance. The appearance of similar design would argue that similar DNA would be involved for the development of each, but this is not the case.This is an opportunity, however, to introduce another transitional fossil:

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Earliest bat fossil reveals transition to flight | Ars Technica
As you can see at right, the fossil is astonishingly well preserved. It comes from deposits that date to about 52.5 million years ago, a time when many mammalian groups were expanding, ... The species has been named Onychonycteris finneyi, meaning "clawed bat" and honoring its discoverer, Bonnie Finney. The clawed bat part refers to one of the many intermediate features that make Onychonycteris the most primitive bat species ever described. In all current and prior fossil species of bats, most of the digits in the wing lack the claws typical of mammalian digits. That's not the case here: all Onychonycteris digits end in claws. The hind limbs are also unusually long, as is the tail, but the limb contains a feature that suggests the presence of a skin flap between the hind limbs and the body.

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The relatively short wings and long hindlimbs place Onychonycteris outside of all previous bat species in terms of the ratio between its limbs. In fact, a plot of this ratio puts the fossil species neatly between bats and long-armed creatures like slothsexactly what would be expected from a species at the base of the bat lineage. The authors argue that the configuration of its limbs, combined with the claws, suggests that it would be powerful climber, able to easily scramble around trees when not flying.

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Note that there is no fossil evidence of the skin, so the attachment of the skin to the skeleton is inferred from secondary evidence. This is the abstract link for the Nature article (you will need sign in privilege to read the full text):

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Primitive Early Eocene bat from Wyoming and the evolution of flight and echolocation | Nature
Here we describe a new bat from the Early Eocene Green River Formation of Wyoming, USA, with features that are more primitive than seen in any previously known bat. The evolutionary pathways that led to flapping flight and echolocation in bats have been in dispute7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and until now fossils have been of limited use in documenting transitions involved in this marked change in lifestyle. Phylogenetically informed comparisons of the new taxon with other bats and non-flying mammals reveal that critical morphological and functional changes evolved incrementally. Forelimb anatomy indicates that the new bat was capable of powered flight like other Eocene bats, but ear morphology suggests that it lacked their echolocation abilities, supporting a 'flight first' hypothesis for chiropteran evolution. The shape of the wings suggests that an undulating gliding—fluttering flight style may be primitive for bats, and the presence of a long calcar indicates that a broad tail membrane evolved early in Chiroptera, probably functioning as an additional airfoil rather than as a prey-capture device. Limb proportions and retention of claws on all digits indicate that the new bat may have been an agile climber that employed quadrupedal locomotion and under-branch hanging behaviour.

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Here is the graphic showing the plot of limb ratios from the full article in Nature: You will notice that Onychonycteris finneyi is exactly between the non-flying cohorts and the flying bats known in the fossil record and modern day.Note that Symphalangus, the blue triangle closest to this fossil, is a gibbon. Bradypodidae, the next closest, are sloths, Sciuridae, near the bottom left, are squirrels, and this would include the flying squirrel. Scandentia are tree shrews, thought by many to share a common ancestor with bats. Cynocephalus is a "flying" lemur: A transitional fossil is one that shows traits intermediate between ancestral forms and descendant forms, and this bat is clearly between modern bats and non-flying arboreal organisms.Enjoy. Edited by RAZD, : addd

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