Talk:Transitional form

Cambrian Explosion
On the issue of the fossil record, is it worth creating an article on the sudden explosion of complex forms during the Cambrian period? Or is this already covered in another article? After all, the Cambrian explosion does support creation, and remains a major obstacle for gradualist evolution. RDFraureuth 12:06, 5 November 2005 (GMT)

Re: "... the coelacanth is thought by evolutionists to be an intermediate between fish and reptiles ..."

Not that I know of. Lots of creationist sites make this claim, but I can't find any evolution sites that actually state that coelacanths are transitional. This appears to be just an oft repeated but false rumour. Roy 15:03, 2 July 2006 (CDT)

Life: The Science of Biology. 2004. Purves et. al. (This textbook is currently used for freshman level Biology for majors.)

Colonizing the Land (p.666) "Changes in the structure of the fins allowed these fishes to move on land. The lobe-finned fishes (class Actinistia) were the first lineage to evolve fins. Lobe-fins flourished from the Devonian period until about 65 million years ago when they were thought to have become extinct. However, in 1938 a living lobe-fin was caught by commercial fishermen off South Africa. Since that time, several dozen specimens of this extraordinary fish, Latimeria chalumnae, have been collected. --Chris Ashcraft 15:50, 2 July 2006 (CDT)

Nothing there that says that coelacanths are/were transitional. In any case,
 * - "these fishes" in the first sentence doesn't necessarily refer to lobe-finned fishes; it will refer to whatever the previous sentence was describing (could be lungfishes - Dipnoi), which context has been omitted.
 * - even if it was referring to lobe-finned fishes it wouldn't necessarily mean that coelacanths were intermediates, since not all lobe-finned fishes are coelacanths. In fact, the early tetrapods are classified as subclass Tetrapodomorpha, while coelacanths are subclass Coelacanthimorpha.
 * - AFAICT it's a misquote: it should be "... the first lineage to evolve jointed fins."

Do you have anything better? Roy 08:13, 5 July 2006 (CDT)

The amount of gaps
Hi!

I searched in your page and on internet on the topic about gaps in fossil record. There are a lot of places, where are mantioned, that there are Big gaps. However, there is not written how big. Wouldn't it be possible to put some numbers or percentage on this topic (like on http://www.strengthsandweaknesses.org/Weaknesses/Fossil.Record.Gaps.htm webpage)?

misunderstanding of a transitional form
Technically, a transitional form is an organism which is supposed to illustrate an evolutionary transition,so they are not necessarily 'an evolutionary link between two distinct groups'. --Kiani francis 14:44, 20 November 2010 (PST)

New Material
Hope everyone doesn't mind that I edited boldly and added in some of my own research on new discoveries, as well as some info about Darwin's writing. This is all groundbreaking from the past decade and to my knowledge nobody else but me is pointing this out. --Jzyehoshua 06:11, 15 April 2012 (PDT)
 * The new detail I've added should prove very useful to the page, and I'm not sure if some of the other material is needed. I moved the Absence of fossil forms section further down, it may need merging into other sections or deletion of less useful information, but I'd prefer to have some consensus on how to move the page forward before I make such changes. Hoping others can provide some suggestions and ideas on what the page structure should look like. --Jzyehoshua 08:43, 15 April 2012 (PDT)


 * Thanks for tackling the page. It was in need of work. Hold off making any further changes while I work through the current revisions, and attempt to merge your additions and some of the older work. For future reference, we generally recommend that "Quotes should be used sparingly" and the number inserted is much higher than is probably appropriate for a single article. I will move a few to other pages (or to a transitional fossil quotes page) and see how if that thinning is sufficient.


 * A couple of contextual problems:

''A major reason Evolutionists have, since 1970, begun classifying dinosaurs as more similar to birds than reptiles, is that unlike modern reptiles, the legs are designed differently so they can stand erect. ''


 * The above is an incorrect statement and not supported by the reference you provided. Dinosaurs are classified as a superorder of reptiles. Attempts to assign both reptile and birds to a common taxa (Sauropsida) are disputed at best and largely based on evolutionary assumptions rather than similar leg morphology. Birds are in-fact believed to have evolved from Saurischia (the lizard-hipped dinosaurs with hip bones similar to modern reptiles) instead of the Ornithischia ornithopods (the bird-hipped bird-footed dinosaurs).


 * Okay, thanks for helping with the page, it's nice to get someone else's input here, I appreciate it! I thought I might be getting to too many quotes and had already removed a few myself, just leaving the citations themselves. As far as dinosaurs being believed to evolve from birds because of leg structure, I thought that was backed up by the citation I provided when it says:


 * http://www.nps.gov/akso/parkwise/Students/ReferenceLibrary/Paleontology/PaleontologyIntro.htm


 * "Dinosaurs have three characteristics that separate them from all other reptiles, living then or now. Dinosaurs hips, knees and ankles are built so that their legs come straight down under their body, unlike alligators for instance whose legs come out to the side and then down. Dinosaurs also have jaw muscles that reach all the way to the top of their skulls, and they have a ridge on their upper arm bone.  Other reptiles may have some of these characteristics but only dinosaurs have all three."


 * This was my most recent addition to the page though, and probably does need another source. For a Creationist acknowledgement of this, see http://www.christiananswers.net/dinosaurs/dinodef.html


 * "Technically, here is how researchers generally define dinosaurs. This is based on physical characteristics that all true “dinosaurs” are supposed to have in common:


 * underslung legs that gave dinosaurs an erect posture
 * a large hole in the bottom of their basin-shaped hip-socket
 * a secondary palate (uncharacteristic of reptiles) that permits dinosaurs to eat and breathe at :*the same time
 * a fairly straight thigh bone with an in-turned head
 * two pairs of holes in the temporal region of the skull (diapsid skull)
 * backward-pointing knees (or elbows) of the front legs
 * forward-pointing knees of the rear legs (rather than pointing sideways)
 * front legs shorter and lighter than the rear legs (in almost every case)
 * a special bone (predentary) at the chin that capped the front of the bottom jaw in some dinosaurs (the ornithischians) land-dwelling creature, rather than marine or airborne"


 * For a secular source, see this by McGraw Hill: http://www.mhhe.com/biosci/genbio/raven6b/graphics/raven06b/enhancementchapters/raven45_enhancement.html


 * Are crocodiles dinosaurs? No. What makes dinosaurs unique, what sets them apart from both crocodiles and thecodonts, are key changes in how they stand and run. Unique Characteristics of Dinosaurs - A variety of unique features are shared by all dinosaurs that set them apart from thecodonts or any other vertebrates, among them the shape of hand, foot, thighbone, and ankle. Two key anatomical changes are of particular importance, changes which improved speed and agility, providing an important evolutionary advantage to early predacious dinosaurs. Strong knee and ankle joints. In bipedal thecodonts (and crocodiles) the knee and ankles flex in a swiveling motion, supporting a swinging walk. Flexing is possible in their ankle because the bones of the left and right sides are connected by a swiveling peg-and-socket joint. In dinosaurs (and birds) the knee is a simple hinge, and peg-and-socket ankles are gone---the foot gives up its grasping design to become a stiff propulsive level, the dinosaur ankle bones firmly attached to the shin bone. These new knee and ankle structures provide the greater strength and stability necessary to support a bulky body (figure 45.56). Upright stance. Thecodonts stood with their legs angled out, in a "Vee" stance. The top of the leg bone (the femur) juts at an inward angle into a shallow groove on the hipbone (the ileum) to form the hip socket. Because bone builds where force is applied, the ileum is thick behind the groove. Dinosaurs stood upright, with legs positioned directly beneath the body. The top of the femur is angled sharply inward, with a ball-shaped tip that fits into a lip on the socket of the ileum. Because there is no pressure sideways, the side of the ileum has no bone at all---there actually is a hole in the side of the socket, where the ileum meets the two other pelvic bones."
 * --Jzyehoshua 03:51, 17 April 2012 (PDT)

''However, the book of Genesis records God fundamentally altering the nature of an early reptile, cursing it to travel in the dust. As such, it is possible dinosaur transitions may simply be evidence of the Biblical change seen in the book of Genesis that God made, altering the fundamental nature of a species or even genera to alter its movement. Indeed, dinosaurs once towered above all life, hence their name "terrible lizard", but the reptiles we see today crawl below the rest of life because of the difference in their limbs. If so, the reptiles that we now see today are simply smaller versions of the giant dinosaurs which once existed, cursed to crawl below other species; humbled from their former greatness.''


 * The above may be an arguable point, but has some conceptual flaws. You have not identified any "dinosaur transitions" that are solved with this theory, and therefore it seems to be confusing the issue. Also there are many vastly different modern reptile orders that can be classified with this body form. If it is your view that dinosaurs were cursed into the modern reptile form - this is not likely as the presence of the dinosaurs in the fossils record testifies to them still being alive at the time of the flood (close to 1500 years after the curse).


 * It is very important that the broadly accepted creation view be represented, and therefore references to creationist publications like the Journal of Creation or the Creation Research Society Quarterly should be used whenever summarizing the creationist view on any particular topic.


 * Alright, not a problem. This section can be removed unless Creationist sources for it can be found. --Jzyehoshua 03:58, 17 April 2012 (PDT)

''Birds being found earlier in the fossil record than mammals and reptiles, by the way, is perfectly consistent with Genesis chapter 1, but unthinkable for evolutionary theory. Genesis 1 says that God created birds and marine life on the 5th day, whereas cattle, creeping things, mammals, and man were all created on the 6th day.''


 * The CreationWiki holds to the young earth view as the principal perspective, and this statement is more in keeping with the day-age creationism view, which must be delineated as such. Most creationist believe that the fossil record represents the animals that died during the global flood rather than being a record of a sequence of evolutionary or creation events. --Ashcraft - (talk) 20:56, 16 April 2012 (PDT)


 * Huh? I didn't think I said anything similar to the Day-Age view there. I personally don't hold the Day-Age view anyway so I'd be surprised if I did. What I believe is that the first few days may have been longer since the solar day didn't begin until the 3rd day when the sun was created, and that the earth was empty and void in Genesis 1:1-3, so while the earth itself may be older, life on earth itself should according to Genesis be young, within the tens of thousands of years. I don't commit to an Ussher chronology because sometimes the genealogies record grandparents as having "begat" someone, but I still think life on earth is pretty young.
 * I furthermore hold to the view Josh McDowell and Don Stewart present in "Reasons Skeptics Should Consider Christianity," that the fossil record is itself evidence of a catastrophe, since deposition rates can't cover from bacteria and scavengers rapidly enough, at 0.24 inches a year, to effectively fossilize anything. Scientists now recognize mass extinction events occurred (pre-cambrian e.g.), the difference is WHEN they occurred. They believe an ice age occurred as recently as 10,000 years ago, and that included the Missoula floods here in North America, evidence of flood-like forces. About the major distinction between us and them is they believe the dates were farther back due to radiometric dating which I consider an extremely shaky methodology given that the electron shield protecting nuclei from decay may itself have evolved, and that decay does occur to radiometric isotopes, as affected by both lava and Beryllium. I think radiometric dating will prove, like the previous 5 dating methods discussed by Brent Dalrymple in Ch. 2 of "The Age of the Earth," to be making a mistake in assuming uniform processes according to Uniformitarianism.
 * --Jzyehoshua 03:58, 17 April 2012 (PDT)
 * In retrospect, I think I see why you thought that. Birds if created the 5th day wouldn't necessarily die first, especially since death hadn't yet entered in. However, they might be oldest and thus after the fall be among the first creatures to die, and thus get recorded as such in the fossil record. I suppose it is a more controversial statement than I'd thought originally when I first made it. --Jzyehoshua 04:26, 17 April 2012 (PDT)
 * In retrospect, I think I see why you thought that. Birds if created the 5th day wouldn't necessarily die first, especially since death hadn't yet entered in. However, they might be oldest and thus after the fall be among the first creatures to die, and thus get recorded as such in the fossil record. I suppose it is a more controversial statement than I'd thought originally when I first made it. --Jzyehoshua 04:26, 17 April 2012 (PDT)


 * You said: Birds being found earlier in the fossil record than mammals and reptiles, by the way, is perfectly consistent with Genesis chapter 1. That is the day-age view of the fossil record - that it represents the organisms that lived at different periods of time - i.e. the sequence of creation events in chronological order. The sorting of animals in the fossil record is instead simply due to the different relative times of death of animals during the flood.


 * What you said about the first few days of creation is also essentially a day-age view. And actually the sun was created on day 4 - after dry land and plants. Longer days wherein plants have no sun makes little sense in that context. The day-age view is essentially at attempt to merge the old-age/Big-bang cosmology view with the creation days. But there are numerous problems not the least of which is that the Earth was formed first according to the Bible - and after eons of star births and deaths according to the Big Bang theory.--Ashcraft - (talk) 06:55, 17 April 2012 (PDT)


 * How is it day-age theory? I don't get it. The sun being created after the plants does make it tough to explain the plants unless the 3rd day was shorter, or else the plants were created near the end. But still, I'm not sure the earth itself is necessarily young given Genesis 1:2, just life on it. I understand what Day-Age theory, I just don't see how you think I supported it with that statement. If birds were made first they might end up dying first due to age, prior to the fossilization of a Flood. The Bible gives at least one example of early humans being fossilized apart from the Flood, in Genesis 14:10, where the kings of Sodom and Gomorrah fell into slimepits (tar pits?). I don't know if you can infer that birds can't occur in the fossil record apart from the Flood. I do think the Flood was the major cause of fossilization, but I'm not sure I'd want to say it was the sole source, which I think is why you assumed that about my statements. --Jzyehoshua 07:20, 17 April 2012 (PDT)


 * It is the theory that the days of creation were instead long periods of day. To say that the first few days of creation were longer than solar days is to say that they were "ages" instead. Personally I think the absence of the sun at that point makes the case even stronger for a literal interpretation. The author's purpose for using the phrase "evening and morning" was clearly to define the word "day" so there would be no misunderstanding of the length of time involved.


 * Certainly there will be some exceptions of fossils forming outside of the flood, but they will be rare (due to the efficiency of decomposition), and given the destructive force of the deluge probably found only above the flood sediments. For example, Neanderthal and Homo erectus fossils are almost certainly post flood humans.--Ashcraft - (talk) 13:14, 17 April 2012 (PDT)


 * Frankly, I never thought it this far through when I made that statement about birds in the fossil record, I just noticed that point in the article I was quoting from and pointed out it appeared Biblically consistent with Genesis 1. All of these implications I never considered to this extent. That section on dinosaurs similar to reptiles was one I put in as an afterthought, I didn't ever expect it to become this big a deal. I have no issue with leaving it out. --Jzyehoshua 07:24, 17 April 2012 (PDT)


 * Understood. No problem. I hope the clarification helped. --Ashcraft - (talk) 12:19, 17 April 2012 (PDT)


 * Yeah, it did. That Dinosaur-reptile subsection was just one I included because the "Possible Biblical Explanations" looked like it could use a 2nd subsection, and based on my own thinking, that was what came to mind. I'd just made the birds in the fossil records comment when it occurred to me while reading one of the science articles, never thought it would be so controversial. I don't really stick to theories per se, I guess - obviously I am Young Earth in questioning radiometric dating and believing life was made in literal, 24-hour days, but at the same time some of what I read elsewhere in Genesis 1 makes me wonder if the first few days could've gone by a different scale. I've never been one to stick to theories and political sides rigidly (I am very socially conservative but liberal/moderate on economic issues, e.g.), I just look at the facts (including what I see in the Bible) and draw my own conclusions independent of everyone else, then look to see whether anyone else's thinking is similar after the fact. I suppose I'm probably somewhere in the middle of both, with aspects of both sides. I do believe a lot of the human transitional forms are evidence of changes the human body underwent following the Flood as well. --Jzyehoshua 15:02, 17 April 2012 (PDT)

New edits
Just wanted to say it looks good, although I think the longevity table might be good for usage on another page, I might move it there later. The page was getting too lengthy and your changes should clean it up as the Biblical explanations section and some of the other stuff could be summarized. I started a new job recently so I've been busy but might find time to edit this weekend. --Jzyehoshua 12:11, 26 April 2012 (PDT)


 * I had placed the table on the discussion page for human longevity until it was completed with Bible references, etc. --Ashcraft - (talk) 06:43, 27 April 2012 (PDT)
 * Oh, sorry, I was in a rush at the time and just made the edit fast. I haven't had much time the last week to follow what was going on. I applied Bible ref template changes, is the table going to be okay now? I will post on the Talk page discussion there as well to see what consensus is, sorry about that. --Jzyehoshua 18:24, 27 April 2012 (PDT)

Proposed addition
I saw the following was removed, and would like to suggest its readdition to the Recent Controversies section, as I think it's a very good summation of how conventional theory on human evolution has gone major changes, due to the discoveries that numerous hominids coexisted and could not be descendants of one another:

According to Encyclopaedia Britannica the following hominins, human transitional forms, exist : However, many are now recognized to overlap in time and space rather than being descendants. Ar. kaddaba and Ar. ramidus coexisted. A. afarensis, K. playtops, A. bahrelgazali, and A. africanus all coexisted. P. aethiopicus, A. africanus, A. garhi, H. habilis, and H. rudolfensis all coexisted. A. sediba, P. boisei, H. rudolfensis, and H. habilis all coexisted as well. So it's getting a bit crowded. Rather than a nice orderly tree progression, they're living at the same times when they're supposed to be descended from one another, with scientists now having to throw the term offshoot at one after another of them, since as famous paleontologist Meave Leakey has noted, "Their co-existence makes it unlikely that Homo erectus evolved from Homo habilis." Coexistence makes it unlikely the coexisting species are descended from each other. As Encyclopaedia Britannica concludes: "Not only were there numerous species of human predecessors long ago, but many of these overlapped in time and space. Habitats favourable for hominin occupation undoubtedly appeared and disappeared throughout much of Africa over and over again with the drastic fluctuations in tropical climates that occurred during the Pliocene and Pleistocene epochs. More species presumably await discovery, because there were probably many evolutionary experiments in these varied and changing habitats. Although the current sample of fossil hominins leads some to the impression that there were only a few hominin lineages, it is far more likely that the human family tree will turn out to be quite 'bushy.' Species names may need to multiply to accommodate the diversity, although a balance needs to be maintained between excessive splitting groups apart and lumping them together."
 * Sahelanthropus tchadensis: 7-6 mya (million years ago)
 * Orrorin Tugenensis: 6 mya
 * Ardipithecus kaddaba: 5.8-4.4 mya
 * Ardipithecus ramidus: 5.8-4.4 mya
 * Australopithecus anamensis: 4.2-3.9 mya
 * Australopithecus afarensis: 3.8-2.9 mya
 * Kenyanthropus platyops: 3.5-3.2 mya
 * Australopithecus bahrelghazali: 3.5-3.0 mya
 * Australopithecus africanus: 3.3-2.4 mya
 * Paranthropus aethiopicus: 2.7-2.3 mya
 * Australopithecus garhi: 2.5 mya
 * Homo habilis: 2.5-1.5 mya
 * Homo rudolfensis: 2.5-1.5 mya
 * Paranthropus boisei: 2.2-1.3 mya
 * Australopithecus sediba: 2.0 mya
 * Paranthropus robustus: 1.8-1.5 mya

--Jzyehoshua 22:57, 27 April 2012 (PDT)

Quotes
Again - For future reference, we generally recommend that "Quotes should be used sparingly" and the number inserted is much higher than is probably appropriate for a single article. --Ashcraft - (talk) 10:36, 18 July 2012 (PDT)

Content move
I merged the introductory content of the human transitional form section of this article with related material on the human evolution page, and moved the rest of the human-specific content to the following title (Recent controversy in hominid ancestry). If edited further, I would suggest keeping the length of the human-specific section of this page no longer than it is currently. Further development is however strongly needed regarding other transitional animals. --Ashcraft - (talk) 17:48, 18 July 2012 (PDT)