Friday, January 4, 2008

Ontogeny recapitulates Phylogeny

Years ago, I was discussing Evolution vs. Creation with a co-worker, who was an Evolutionist. The owner of the company interrupted our conversation, telling me, "Ontogeny recapitulates phylogeny. That's all you need to know." He explained that it took him 4 years of college to learn those 3 words. I informed him that the idea that "ontogeny recapitulates phylogeny" (which basically means that the stages of an embryo prove evolution...for example, it used to be thought that an embryo first developed gills, but it was later discovered that those were not gills at all) was shown to be false over 100 years ago! He had no reply. I should have asked him how many years ago it was that he went to college! (LOL!)

(Jeff Jenkins)


human rorschach test said...

That theory always was a clumsy one. It used a series of drawings of the stages of embryonal development that had been purposefully drawn to look more like different species in a process of 'evolving' into a baby!

The modern application of this theory has a few neat observations involved with it like these:

1) Whales, which have evolved from land mammals, don't have legs, but tiny remnant leg bones lie buried deep in their bodies. During embryonal development, leg extremities first occur, then recede. Similarly, whale embryos have hair at one stage (like all mammalian embryos), but lose most of it later.
2) The common ancestor of humans and monkeys had a tail, and human embryos also have a tail at one point; it later recedes to form the coccyx.
3) The swim bladder in fish presumably evolved from a sac connected to the gut, allowing the fish to gulp air. In most modern fish, this connection to the gut has disappeared. In the embryonal development of these fish, the swim bladder originates as an outpocketing of the gut, and is later disconnected from the gut.

I am puzzled about the appendix, earlobes, wisdom teeth, ear muscles, body hair, subclavius and palmaris muscles, vomeronasal organs, neck ribs, 'goosebump muscles', plantaris muscle, the thirteenth rib, pinky toes, pyramidalis muscle, sinuses and the remnants of sperm ducts in women and nipples on men.

I think disproving evolution should be on the sidelines until the purpose for all these things are explained by theology.

Jeff said...

Addressing every single thing you mentioned would take pages and pages of writing, so for the moment, here's an explanation concerning nipples on men:

"Every embryo starts its development as a female by default, which means every embryo is equipped with nipples from the start, whether male or female. Then, at the right time during development, and if the egg was fertilized by a sperm carrying the Y chromosome, the development changes direction and groups of cells that would have become ovaries, for example, instead become testicles, etc. But in that case, the nipples remain simply because they're already there. Males have nipples because they were females FIRST.

Believe it or not, this has an astounding analogy with the manufacture of automotive engine blocks. Engine blocks are cast from aluminum or iron and a common feature of these castings--called a "boss"--provides a way to mount the engine and attach ancillary components to the block later on; things like alternators, power steering pumps, AC compressors. etc. A "boss" is simply a protrusion in the casting that is suitably reinforced so that other components can be fastened to the casting.

On any given car you are likely to find blank bosses cast into the engine block which would appear to serve no purpose. That is, no ancillary components of any kind are bolted to them. Often you'll discover those unused bosses are there for optional accessories which that particular car did not come equipped with… air conditioning, for example. The engineers who designed the casting designed a single casting that is equipped with every boss it will need for the broad range of applications it was intended to fit, knowing full well that in many applications, the bosses would be unused. The engineers knew it was a waste of resources to cast a different block for each application and they also knew that the unused bosses wouldn't create any kind of functional disadvantage.

Design and manufacturing strategies like these are economical, elegant and efficient, and are the products of intelligent designers. It turns out we find evidence of very similar design strategies in the human body, nipples on men is just one example. Once again, an argument which was offered to challenge ID turns out to support it in a very profound way."

Jeff said...

At risk of possibly making this entire comment section way too long, I will include an explanation for the appendix as well:

"For years, the appendix was credited with very little physiological function. We now know, however, that the appendix serves an important role in the fetus and in young adults. Endocrine cells appear in the appendix of the human fetus at around the 11th week of development. These endocrine cells of the fetal appendix have been shown to produce various biogenic amines and peptide hormones, compounds that assist with various biological control (homeostatic) mechanisms. There had been little prior evidence of this or any other role of the appendix in animal research, because the appendix does not exist in domestic mammals.

Among adult humans, the appendix is now thought to be involved primarily in immune functions. Lymphoid tissue begins to accumulate in the appendix shortly after birth and reaches a peak between the second and third decades of life, decreasing rapidly thereafter and practically disappearing after the age of 60. During the early years of development, however, the appendix has been shown to function as a lymphoid organ, assisting with the maturation of B lymphocytes (one variety of white blood cell) and in the production of the class of antibodies known as immunoglobulin A (IgA) antibodies. Researchers have also shown that the appendix is involved in the production of molecules that help to direct the movement of lymphocytes to various other locations in the body.

In this context, the function of the appendix appears to be to expose white blood cells to the wide variety of antigens, or foreign substances, present in the gastrointestinal tract. Thus, the appendix probably helps to suppress potentially destructive humeral (blood- and lymph-borne) antibody responses while promoting local immunity. The appendix–like the tiny structures called Peyer’s patches in other areas of the gastrointestinal tract–takes up antigens from the contents of the intestines and reacts to these contents. This local immune system plays a vital role in the physiological immune response and in the control of food, drug, microbial or viral antigens. The connection between these local immune reactions and inflammatory bowel diseases, as well as autoimmune reactions in which the individual’s own tissues are attacked by the immune system, is currently under investigation.

In the past, the appendix was often routinely removed and discarded during other abdominal surgeries to prevent any possibility of a later attack of appendicitis; the appendix is now spared in case it is needed later for reconstructive surgery if the urinary bladder is removed. In such surgery, a section of the intestine is formed into a replacement bladder, and the appendix is used to re-create a ’sphincter muscle’ so that the patient remains continent (able to retain urine). In addition, the appendix has been successfully fashioned into a makeshift replacement for a diseased ureter, allowing urine to flow from the kidneys to the bladder. As a result, the appendix, once regarded as a nonfunctional tissue, is now regarded as an important ‘back-up’ that can be used in a variety of reconstructive surgical techniques. It is no longer routinely removed and discarded if it is healthy."

Jeff said...

OK, I'm going to risk adding another comment, even though I know I'm making this long:

"Whether or not we have a feasible explanation of the function of an appendix is really quite irrelevant...Even if we DO NOT have knowledge of a specific function of any given organ does not mean that organ doesn't have a function. This is the same mistake made with regard to "junk DNA." Evolutionists tend to write it off as "junk" simply because they don't have knowledge of its function. It's difficult to imagine a conclusion which exhibits more arrogance than that. In truth, its just another argument from ignorance. We don't know what its function is, therefore it must be junk. And sure enough, more research is revealing functions in what used to be called "junk DNA." As for the appendix, just because you can remove one from a patient without a significant impact on their health or lifestyle in no way confirms that the appendix has no function. It only confirms that, assuming the appendix HAD a function, it wasn't a function that was absolutely critical."

Jeff said...

Oh, well, I've gone this far; I might as well post more, then. Here is an interesting comment from someone who I don't think is even a Christian:

"On the supposed atavistic hindlimbs of whales:

This paper is almost exclusively responsible for the modern myth of the whale leg. Unfortunately Darwinists typically choose to ignore this portion completely. It's pretty much like like the old myth about "gills" in human embryos. The idea that the embryo of a complex animal goes through stages resembling the embryos of its ancestors is called the Biogenetic Law. This "Law" known as recapitulation theory (ontogeny recapitulates phylogeny) was formulated in 1866 by Haeckel, an early convert to Darwinism who also famously fake evidence in attempts to persuade doubters. Of course, this gill slit fraud is pretty infamous now.

In a paper entitled ’Untersuchungen an walen,” Professor W. Kukenthal has described external rudimentary hind limbs in three early embryos of Megaptera. These appear as two more or less caudally directed papillae on either side of the genital organ in the same relative position as the hind limbs which I have described in this paper. In Kukenthal’s Stage I (an embryo 32 mm. in length) the rudiments are best developed and are 12 mm. long. In Stage II (an embryo 28 mm. long) the rudiments are somewhat less distinct, reaching a length of 9 mm. In Stage III (an embryo 30 mm. long) the hind-limb rudiments have still more decreased in size and appear as minute papillae.
Kuikenthal has also discovered hind-limb rudiments in embryos of Phocaena communis and P. dalli, and Guldberg has recorded them in embryos of Lagenorhynchus acutus and Phocaena communis.
Kukenthal states that the hind-limb rudiments are found in later embryonic stages of the Mystacoceti than in the Odontoceti and concludes that in the evolution of cetaceans the hind limbs lost their functional character in the Odontoceti earlier than in the Mystacoceti.
Since Kiikenthal’s and Guldberg’s researches have shown that external hind-limb rudiments are still present in some cases in embryonic life, it is by no means impossible that, these vestigial organs should continue their growth and persist until the adult stage.

Keep in mind this is a fairly old document. They’re interpreting this evidence in the light of recapitulation theory, claiming it as ”rudimentary hind limbs” present during development. Another valid interpretation would be to consider this structure as temporary ”scaffolding” (extra-embryonic) that is ”normally” removed as the creature grows. After all, many other creatures have temporary structures that have no apparent ultimate morphogenetic significance (as in, they disappear completely in later stages of development) but they DO serve a purpose. And based upon the description given that does appear to be the case...but that doesn't stop certain Darwinists from hanging onto this modern myth.

On human tails and the coccyx:

First of all the, the coccyx is only a vestigial organ if one assumes a tail in the past (on a side note, by the definition of vestigial organ the component in question doesn't have to be completely can lose its original function and gain new ones). Several muscles converge from the ring-like arrangement of the pelvic bones to anchor on the coccyx, forming a bowl-shaped muscular floor of the pelvis called the pelvic diaphragm. The incurved coccyx with its attached pelvic diaphragm keeps the many organs in our abdominal cavity from literally falling through between our legs. Some of the pelvic diaphragm muscles are also important in controlling the elimination of waste from our body through the rectum.

Human “tails” are disarrangements that occurred during embryological development. Most of them are just flaps of skin but some do have useless disconnected bones in them that would appear to be shaped along the same lines as the bones in the coccyx. I highly doubt these “tails” are normal extra-embryonic features. That interpretation of the data is only a possibility with the whale leg so don’t attempt to confuse the two in an attempt to make a bad argument. I don’t believe the precise genetic basis for these examples of “tail” growth in humans is known, but I’d say the best bet is Hox (homeobox) genes. Mutations in these genes cause alterations in the development of the axial skeleton (vertebral column and ribs) and limbs, among other things. The Pax-6 regulatory group–which is about 130 amino acids long–shares a 94% similarity between humans and insects. They are conserved across all animal phyla, with similar or homologous functions (you can argue over the cause of this–designer reuse or common descent–later). Mutations in these regulatory gene sets can cause biological components to not be built (an animal losing their hind legs). They can result in more than the correct number of elements being built (as in the case of Hox-4.6 in chickens which create an extra “thumb”). They can even result in the construction of components in the wrong places. Ultimately, manipulations to these genes can only result in the rearrangement of elements already present in the biological development plan for a given organism. If I wanted to give someone’s child a tail, we’d need to know the exact pattern of expression of the correct gene(s) and how to achieve it by artificially engineering promoter-gene fusions and inserting them into the genome of an embryo. Otherwise you’d end up with these useless extensions as seen in the above pictures.

But let’s ask some questions. Some human females are born with mammary glands under the armpits; does this mean they’re regressing to an earlier mammalian stage? After all, some mammals have mammary glands in their armpits. Does a second nipple on my right breast mean I’ve generated CSI? Of course not. Besides, if the bony tail is evidence that we evolved from tailed creatures, why also bother to insist that we evolved from a common ancestor with pan troglodytes, which doesn’t have tails?

But let's say you argue that it doesn't have to be a fairly "recent" common ancestor that had a tail. In effect, you might claim that this reversion to conserved tail information comes from an ancestor from before Ardipithecus ramidus–over 4.5 million years ago. Unfortunately Sahelanthropus tchadensis, dated at around 7 million years, is just a skull so we cannot tell if it had a tail. Or we can go back 20 million years ago to Proconsul heseloni, which lived in the trees of dense forests in eastern Africa. Proconsul is claimed to have had features that closely link it to the common ancestor of humans—for example, the lack of a tail. But you go ahead and persist to claim that this useless information for tails has somehow survived elimination by Darwinian processes for millions of years instead of accepting that a simple genetic mistake is the cause. Just exactly who is stretching logic here?

Obviously I’m in the search for the truth, not some tired attempt to defend an old framework. Whether humans came from pan troglodyte, or another route through convergent evolution, or were specially created…I don’t care. I just want to make certain it’s true and TalkOrigins does NOT have that goal."
Patrick | Wed, 2006-10-04 20:37

human rorscach test said...

I believe you are copying your answers from your enemy :)
Here' is a picture of a baleen whale skeleton. It has the vestigial rear leg bones I speak of. Some large primitive snakes have them as well.

Please continue if you wish, I find your answers fascinating. I had read that the coccyx had a function, but also that it's removal hampered people in no way, other than they could no longer break it!

Jeff said...

As far as "copying answers from my enemy," even if I don't agree with everything some of my sources believe, I still may find some of their points interesting and helpful. For example, I own a book written by a Theistic Evolutionist, and I find what he says interesting, even though I don't completely agree with him.

Thank you for saying that you find my answers fascinating. I enjoy talking about things having to do with God. And for me, the more I find out about the natural world, the more awestruck I am about God's power, artistic creativity and desire for variation.

What Darwinists see as adaptive behavior, I see as God putting that ability in that creature, possibly similar to the way God gives different people different gifts and talents.

And as a Graphic Artist, I look at the designs on a butterfly or a duck, or the stripes on a zebra, and I can see the artistic perfection in those designs.

I also see great beauty (not only in the design, but also the use of bright colors, etc.) in so many creatures. Even many insects have beautiful colors and designs on them. I once saw a velvet ant, and its 'fur' and color were amazingly beautiful.

In addition, I see geometric shapes in nature as well. A spider's web, the ripples in a pond when you throw a rock in, the rings of Saturn, etc.

If all those colors and geometric designs are just coincidental accidents or evolved mutations, then why do I, as a human being, find them beautiful? How does evolution explain the concept of beauty? Or, for that matter, how does evolution explain art and creativity?