Chapter 26

Recapitulation Theory: How Embryology Does Not Prove Evolution

Evolutionists have speculated embryos replay the evolutionary history of their species as they develop - but this is demonstrably false.

by Dr. Elizabeth Mitchell on September 5, 2020


Do developing embryos replay the evolutionary history of their species as they develop? These ideas have led people to believe that what is in the womb is merely an animal, and these types of arguments have been used to promote abortion and the false worldview of evolution.

Summed up in the popular high-school statement, “Ontogeny recapitulates phylogeny,” recapitulation theory (also known as the biogenic law) was popularized by evolutionist Ernst Haeckel’s famous (or infamous) 19th-century illustrations intended to demonstrate how embryos pass through stages reminiscent of their evolutionary ancestors.

While the inaccuracy of Haeckel’s drawings became apparent almost immediately, they continued to be presented in textbooks, museums, and the secular media as “proof ” of evolution even into this century. Evolutionary biologists who freely acknowledge the inaccuracy of the drawings continue to debate the validity of the “theory”1 and its variants. Applications of recapitulation theory are widely accepted in other disciplines, such as linguistics and developmental psychology.

To many people, the evolutionary principles underlying recapitulation theory are fundamental truths, so the theory retains its authority in their thinking even when it requires substantial modification to exist alongside observable facts. Moreover, in recent years even Haeckel’s evolutionary critics have shifted gears and begun to rehabilitate his reputation and his work. Forgiving the “liberties” he took, some now consider him positively brilliant for manufacturing pictures to prove what he “knew” must be true.

Many creationists are under the impression that evolutionists have abandoned recapitulation theory. Its persistence in the educational system, however, testifies to its usefulness even in the hands of those who believe that it has some problems. It remains a tool to explain evolutionary principles to students and to convince them that evolution is true.

Furthermore, many still believe that recapitulation theory (in some form or other) is sufficiently true to count as convincing evidence for evolution. And in the world of professional evolutionists, while some debate which variations of it they accept, others consider it a valid predictor of evolutionary stages and use it to unravel the secrets and subtleties of an evolutionary past shrouded by deep time and an incomplete fossil record. Thus, recapitulation theory continues to fuel the evolutionary thinking of students from the cradle to college, the lay public, and academic professionals.

Big Words

“Ontogeny recapitulates phylogeny.” The way that phrase rolls off the tongue combined with the compelling visual imagery that usually accompanies it appeals to the ear, the eye, and the mind. After all, how could big words that rhyme so well convey an untruth? But what do all those big words mean?


Ontogeny means development from the earliest stages to maturity. In biology, ontogeny is roughly synonymous with embryologic development. Certainly, a fertilized egg must pass through a number of stages as it develops into a mature organism ready for life outside its mother’s womb or its egg. A developing embryo changes its shape dramatically as it grows and morphs into its mature form.

Some anatomical structures appear in an apparently simple form and develop complexity. (That morphological simplicity is generally only a superficial impression, but the illusion of simplicity fits the evolutionary story that embryology supposedly tells.) Some anatomical structures disappear completely or remain only as vestiges (literally, “footprints”) in the final product. Vestigial organs are commonly (and erroneously) viewed as “useless” anatomical structures left over from our evolutionary past.


Phylogeny refers to evolutionary ancestry. It is based on the presumption that all living organisms evolved from simpler forms through natural processes. The phylogenetic tree of life is a metaphor for the branching of the earliest life forms into stem branches, which, through the ongoing development of complexity and continued divergence into more and more branches, eventually produced the life forms we see today. Moreover, Haeckel, like many evolutionists then and now, maintained that this phylogeny is monophyletic — that all animal life can be traced back to a single common ancestor.


Recapitulation refers to summarizing, repeating, or restating something. Thus, “ontogeny recapitulates phylogeny” is the claim that the developing embryo goes through stages that resemble, at least structurally, the various animals on that organism’s ancestral trip up the tree of life.

Simply stated, Haeckel claimed that the embryonic forms of an animal resembled the adult organisms in its evolutionary ancestry. Because observation shows that developing embryos do not resemble the adults on the evolutionary tree of life, a modified form of the theory holds that an embryo only resembles the embryos of its evolutionary ancestors. A more recent reinterpretation of Haeckel’s claims credits him with only claiming recapitulation applies to individual traits, rather than for entire embryonic stages.2

Seen and Unseen

Ontogeny is observable. Embryonic development of an organism can be studied through the lens of actual scientific methodology. Even the development of the human embryo has been studied in great detail.3 The anatomy of each stage of human embryonic development and that of many animals has been examined, sketched, and photographed.

When Haeckel’s embryo drawings were published, they purportedly showed a comparison of the embryos of a number of vertebrates. Some see Haeckel’s illustrations as blatant frauds, and others say he took artistic liberties to emphasize a point. Regardless, the images were almost immediately shown to be inaccurate by comparison with observable reality.

Phylogeny is not observable. No amount of scientific achievement makes it possible to see back through time to observe the purported upward evolution of life. Neither does biological research reveal any mechanism by which a simpler kind of organism can acquire the genetic information to become a more complex kind of organism.

Furthermore, no such transformation has ever been observed. Fossils labeled “transitional forms” are actually just animals with a variety of characteristics interpreted through an evolutionary imagination that connects the dots through time.

Thus, phylogeny is a figment intended to explain life without God. The claim that “ontogeny recapitulates phylogeny” is a claim that the observable steps in embryonic development are similar to and therefore reveal the unobservable evolutionary past of that organism.

Because the unobservable evolutionary past is not amenable to scientific examination, it is impossible to “test” the recapitulation claim. But because “evolution” is presented to students and to the public and held by the majority of mainstream scientists to be indisputable fact, recapitulation theory becomes a tool for education, a visually appealing bit of evidence, and a paleontological predictor to order fossils into the “right” lineages.


While Haeckel’s drawings are the expression of recapitulation theory most familiar to modern schoolchildren, college students, and adults, the idea did not originate with Haeckel or even with Darwin. The germs of recapitulation theory can be found in the ancient world, but it gradually acquired its more modern form in the 19th century, with contributions by J.F. Meckel (1811), Karl Ernst von Baer (1828), Charles Darwin (1859), and finally Ernst Haeckel (1866).

Haeckel was a professor of zoology in Germany. He was particularly moved by Darwin’s Origin of Species, and actively promoted Darwinian evolution to the public and to academia. As he taught how humans gradually developed through upward evolution along a tree of life, he presented hypothetical simple organisms as if they were real, an ape-man for which he had no evidence, and his infamous doctored embryo sketches.


Haeckel’s famous (infamous) set of 24 drawings purporting to show eight different embryos in three stages of development, as published by him in Anthropogenie, in Germany, 1874. This is the version of his drawings most often reproduced in textbooks. Left to right are shown embryos of a fish, salamander, turtle, chicken, pig, cow, rabbit, and human. Top to bottom depicts three stages of development. The drawings contain errors intended to emphasize embryonic similarity and support recapitulation theory. IMAGE: from M. Richardson and G. Keuck, “Haeckel’s ABC of Evolution and Development,” Biological Reviews of the Cambridge Philosophical Society, 77 no. 04 (2002): p. 495–528.

Haeckel’s version of the “biogenetic law” held that embryos looked like the adult forms of their evolutionary forebears. He wrote that embryonic development paralleled phylogenetic (evolutionary) history — that “embryonic development is a short and rapid re-run, or recapitulation, of evolution.”4 To support his claim, in his book Natürliche Schöpfungs-geschichte,5 Haeckel included sketches of embryos substantially altered to make his point. “His drawings are also highly inaccurate, exaggerating the similarities among embryos, while failing to show the differences,” explains embryologist Michael Richardson, lead author of a famous 1997 article refuting Haeckel’s claims.6

Soon after publication, Haeckel’s 19th-century contemporaries spotted the fraud and publicized it. For instance, in 1874, William His, after critiquing Haeckel’s ideas and demonstrating that many of the embryo figures were “invented,” concluded, “The procedure of Professor Haeckel remains an irresponsible playing with the facts even more dangerous than the playing with words criticized earlier.”7

For over a century, criticism from the evolutionary scientific community has continued.

Scientific objections to Haeckel’s drawings . . . include charges of:

  1. doctoring (the alteration of images during copying);
  2. fabrication (the invention of features not observed in nature); and
  3. selectivity (the use of a misleading phylogenetic sample).8

The most generous and gracious modern assessments have been unable to allay charges of falsification, and Haeckel even admitted to some of the accusations. For instance, to the charge that he printed a woodcut of a single turtle embryo three times, altered to represent three different species, he confessed to “an imprudent folly” necessitated by a shortage of time.9

Despite the almost immediate rejection of Haeckel’s evidence by much of the scientific community, his rather impressive fabrications did their job: they found their way into textbooks as evidence illustrating evolutionary claims for over a century. Countless children and adults — and young women coaxed to proceed with abortion — have been told that the human embryo goes through a fish stage, an amphibian stage, and a reptilian stage. Attesting to the sometimes-disputed fact that these fraudulent “teaching tools” persisted in the educational system despite their known errors and general rejection in the scientific community, leading evolutionist Stephen Gould in the year 2000 wrote:

Haeckel had exaggerated the similarities by idealizations and omissions. He also, in some cases — in a procedure that can only be called fraudulent — simply copied the same figure over and over again. At certain stages in early development, vertebrate embryos do look more alike, at least in gross anatomical features easily observed with the human eye, than do the adult tortoises, chickens, cows, and humans that will develop from them. But these early embryos also differ far more substantially, one from the other, than Haeckel’s figures show. Moreover, Haeckel’s drawings never fooled expert embryologists, who recognized his fudgings right from the start.

At this point, a relatively straightforward factual story, blessed with a simple moral story as well, becomes considerably more complex, given the foils and practices of the oddest primate of all. Haeckel’s drawings, despite their noted inaccuracies, entered into the most impenetrable and permanent of all quasi-scientific literatures: standard student textbooks of biology. . . . We should therefore not be surprised that Haeckel’s drawings entered nineteenth-century textbooks. But we do, I think, have the right to be both astonished and ashamed by the century of mindless recycling that has led to the persistence of these drawings in a large number, if not a majority, of modern textbooks!10

In a succinct summation of Haeckel’s work, Gould concluded that Haeckel, who used his doctored diagrams as data to support his scientific hypotheses, committed the “academic equivalent of murder.”11

A 1997 study of comparative embryology, published in the journal Anatomy and Embryology by embryologist Michael Richardson, then of London’s St. George’s Hospital Medical School, also called attention to the persistent acceptance of Haeckel’s fraudulent diagrams. He found that Haeckel had resized embryos and eliminated limb buds and heart bulges to enhance similarity. He wrote, “These drawings are still widely reproduced in textbooks and review articles, and continue to exert a significant influence on the development of ideas in this field.”12 Gould quotes Richardson saying, “I know of at least fifty recent biology textbooks which use the drawing uncritically.”13

While some excuse Haeckel’s diagrams as mere schematics, these “schematics” were clearly meant to systematically and deceptively improve on nature. For instance, he selectively removed limbs on one of his embryos while rendering others perfectly, commenting that they were similar with “no trace of limbs or ‘extremities’ in this stage.”14 According to Richardson, the “intent [of these systematic alterations] is to make the young embryos look more alike than they do in real life.”15

Despite overwhelming evidence that has been used to refute Haeckel’s claims and the manufactured data he used to support them, Richardson and colleagues write, “The idea of a phylogenetically conserved stage has regained popularity in recent years.”16 To assess the merits of recapitulation theory and Haeckel’s work, they conducted a systematic examination of embryos from all sorts of vertebrates, noting that modern textbooks typically confine their attention to the frog, the chick, and the “typical” mammal.

They compared the most phylotypic stage of each — the stage at which vertebrate embryos possess comparable characteristics such as a notochord, pharyngeal arches (“gill slits”), a neural tube, somites (segments of undifferentiated blocks of embryonic mesoderm), and a postanal tail (a posterior extension of the embryo’s developing musculoskeletal structures beyond the anus).

Richardson et al. in 1997 confirmed that even the earliest stages of embryonic development vary greatly between vertebrate species. They attributed these differences to evolution, as they hold an evolutionary worldview. But their paper demonstrated, on the basis of rigorous comparative embryology, that the “biogenetic law” as commonly understood is false.17

A quick Internet search today will produce many references to recapitulation theory as “inadmissibly simplified,”18 “outdated” and “buried,”19 “refuted,” “defunct,” and “largely discredited.” Haeckel’s drawings are recognized by many as “fraudulently modified”20 “misinformation.”21 Embryologist Michael Richardson was quoted in a 1997 issue of Science magazine saying Haeckel’s work was “turning out to be one of the most famous fakes in biology.”22 So has Haeckel’s work — so heavily criticized even in the evolutionary community — dropped off the scene? No. Why is that?

Despite over a century of widespread acknowledgment that Haeckel faked his pictures, Haeckel’s claims and even colorized adaptations of his diagrams still show up in the popular press and even textbooks. For instance, the cover story of Time magazine (November 11, 2002) reported that the human embryo at 40 days “looks no different from that of a pig, chick or elephant. All have a tail, a yolk sac and rudimentary gills.”23 Even 21st-century textbooks perpetuate this 19th-century fraud. Sylvia Mader’s 2010 edition of Biology, for instance, features colorized Haeckel-ish embryos and teaches, “At these comparable developmental stages, vertebrate embryos have many features in common which suggests they evolved from a common ancestor.”24

In a world where evolutionary educators decry any effort to “teach the controversy” in public schools — allowing students to be exposed to facts that reveal problems with evolutionary dogma — the convenient foot-dragging on the removal of this compelling lie from curricula is telling.

Those Fishy Gill Slits

Our embryonic “gill slits” are possibly the most oft-cited anatomical “proof ” of our fishy ancestry. Inside the Human Body, a popular 2011 BBC1 program hosted by Dr. Michael Mosley, provides a typical example. The program features a state-of-the-art, high-quality video of human embryonic development called “Anatomical Clues to Human Evolution from Fish.”25 The video was produced by digitally splicing scans taken in early pregnancy. Mosley interprets the developing features as anatomical proof of fish in our evolutionary past. Among these are “gill-like structures,” a reference to the “gill slits.”26

The poorly named “gill slits” in human embryos are not anything at all like gills and are not even slits, just folds of tissue destined to develop into various anatomical parts of the head and neck. They never have a function or a structure remotely resembling gills. They don’t even turn into anything having to do with the lungs. Never in the course of development does a human embryo absorb oxygen from water as fish do with gills.

Evolutionist Steven Jay Gould writes, “In Haeckel’s evolutionary reading, the human gills slits are (literally) the adult features of an ancestor” (emphasis in original).27 In later writings, Haeckel did not ascribe a respiratory function to these structures in the non-fish embryo. He still maintained that there were actual gill slits and gill arches in the non-fish embryos but that they had evolved into other structures. He wrote in 1892 that “we never meet with a Reptile, Bird or Mammal which at any period of actual life breathes through gills, and the gill-arches and openings which do exist in the embryos are, during the course of their ontogeny, changed into entirely different structures, viz. into parts of the jaw-apparatus and the organ of hearing.”28 And by 1903 he wrote of the “total loss of respiratory gills,” saying that “in the embryos of amniotes there is never even a trace of gill lamellae, of real respiratory organs, on the gill arches.”29

Evolutionists consider homologies in fish gills, fish jaws, reptilian jaws, and mammalian ear bones to be sequential evolutionary developments that demonstrate the common evolutionary ancestry of fish, reptiles, and mammals. Homologous structures are the different anatomical structures that form from a similar embryonic structure. Meckel’s cartilage, for instance, has different destinies in different creatures. Meckel’s cartilage supports the gills in cartilaginous fish. It ossifies to form the jaws of bony fish and reptiles. And in mammalian embryos, Meckel’s cartilage helps shape the middle ear bones and the mandible; then it virtually disappears. But each creature has its own kind of DNA directing the process, and at no time in science do we see DNA of one creature mutating to produce new information that can change the organism into a new kind. And at no point do these so-called mammalian “gill slits” have anything to do with gills or respiratory structures.

Mammalian “gill slits” are folds in the region of the tiny embryo’s throat. By the 28th day of life, the embryo’s brain and spinal cord seem to be racing ahead of the rest of the body in growth. Therefore, for a time, the spinal cord is actually longer than the body, forcing the body to curl and flexing the neck area forward. (This curled embryo with the long spinal cord is mistakenly accused by some people of having an animal’s tail.) Just as many people develop a double chin when bending the neck forward, so the embryo has folds in its neck area due to this flexing.

Gill slits, thus, is a misleading name, since these folds are neither gills nor slits. Another popular name, branchial arches, is just as deceptive because branchial comes from the Greek word for “gills.” Somehow the name neck folds just isn’t fancy enough for our scientific minds, so these folds are called pharyngeal arches, since they are arch-shaped folds near the throat. (Pharyngeal is the scientific word for things having to do with the throat. When you say you have a sore throat, your doctor says you have pharyngitis.) The creases between the folds are called pharyngeal clefts, and the undersides of the folds are called pharyngeal pouches. The pouches and clefts are not connected by an opening. Each fold shapes itself into specific structures, none of which are ever used for breathing. The outer and middle ear as well as the bones, muscles, nerves, and glands of the jaw and neck and even the immune system’s thymus gland develop from these folds as tissues differentiate in compliance with the blueprint in human DNA.

Nevertheless, the meaning-packed terms gill slits and gill-like structures persist. But mammalian pharyngeal arches are no more related to gills — ancestrally or otherwise — than stars are to streetlights.

Even texts that refer to these folds by correct names sometimes perpetuate the powerful gill slit myth. For instance, Mader’s Biology (2007 edition) correctly describes the ultimate anatomic destiny of each pharyngeal arch component and then asks:

Why should terrestrial vertebrates develop and then modify such structures like pharyngeal pouches that have lost their original function? The most likely explanation is that fishes are ancestral to other vertebrate groups.30

What “lost original function”? No one has ever documented that pharyngeal pouches in the embryos of terrestrial vertebrates function as gills or that adult terrestrial vertebrates ever had gills. Preserved in textbooks and the media, the fishy ancestral myth persists. Our unseen and unverified fishy past still surfaces regularly in the assumptions that the pouches/folds/slits, or whatever-they-get-called, are leftovers from a fish ancestor.

In a chilling application of this misinformation, many abortionists have used Haeckel’s embryologic falsehoods to assuage the guilt of women seeking abortion, telling them they’re only removing something like a fish, not a baby. The late Dr. Henry Morris observed, “We can justifiably charge this evolutionary nonsense of recapitulation with responsibility for the slaughter of millions of helpless, pre-natal children — or at least for giving it a pseudo-scientific rationale.”31

The Current Debate

Given all the data researchers have used to refute recapitulation theory, do real scientists still cling to its discredited notions? After all, it’s one thing to foist a fabricated, oversimplified bit of evolutionary evidence on the gullible public and generations of children and college students, but do professionals hang on to these notions, too?

While some professional evolutionary scientists have given up on recapitulation theory altogether, many continue to cling to various permutations of it.

Some distance the beloved recapitulation dogma from Haeckel and look back a bit further to Karl Van Baer’s 1828 version that claimed embryonic stages only recapitulate the embryonic stages of their evolutionary ancestors. Neither version has ever truly explained embryologists’ observations, however. And as Richardson’s work has clearly demonstrated, vertebrate embryos have discernible differences even at the earliest stages, an observation that finally strips the underpinnings of both versions. Thus, to make the theory work, some evolutionary biologists who wish to keep it have modified it, choosing which parts they can make the best case for.

Ernst Mayr’s modification, laid out in “Recapitulation Reinterpreted: The Somatic Program,” appeared in 1994 in the Quarterly Review of Biology. He wrote that despite “the disrepute into which Haeckel’s claims had fallen . . . every embryologist knew that there was a valid aspect to the claim of recapitulation.”32 A 2012 paper co-authored by Richard Lenski, “Ontogeny Tends to Recapitulate Phylogeny in Digital Organisms,” notes that Mayr’s “sentiment is still widely held today, and the idea that ontogeny recapitulates phylogeny in some form has its modern proponents.”33

Making It Work

Recapitulation theory is just too appealing to abandon for many evolutionists. Lenski’s group wrote, “At a minimum, the fact that the debate has continued for so long lends credence to Mayr’s view that there is at least some validity to recapitulation.”34

Perhaps the most dramatic rehabilitation of Haeckel has come at the hands of one of his best-known modern critics, Michael Richardson. In the 2002 paper “Haeckel’s ABC of Evolution and Development,” published in Biological Reviews of the Cambridge Philosophical Society, Richardson and Gerhard Keuck re-examined Haeckel’s work. They wrote:

Haeckel recognized the evolutionary diversity in early embryonic stages, in line with modern thinking. He did not necessarily advocate the strict form of recapitulation and terminal addition commonly attributed to him. Haeckel’s much-criticized embryo drawings are important as phylogenetic hypotheses, teaching aids, and evidence for evolution. While some criticisms of the drawings are legitimate, others are more tendentious. . . . Despite his obvious flaws, Haeckel can be seen as the father of a sequence-based phylogenetic embryology.35

Richardson and Keuck conclude that the biogenetic law is valid after all if applied to the evolution of “single characters only” and not entire embryonic and evolutionary stages.36 In other words, so long as only single traits are followed through evolutionary time and embryonic development, Richardson is now aboard the recapitulation bandwagon.

Richardson and Keuck’s analysis of Haeckel’s work was not able to expunge the charge of falsification, but they clearly have granted him absolution. They and others support “Haeckel’s practice of filling in gaps in the embryonic series by speculation”37 even though “Haeckel presented the embryo drawing as data in support of his hypotheses”38 and not just helpful teaching aids.

Haeckel’s artistic liberties are clearly not the result of any lack of observation skills or artistic ability. One of his latter-day apologists has even praised Haeckel’s diagrams of single-celled radiolarians, noting their resemblance to modern light microscope images and electron micrographs.39 Haeckel was a skilled illustrator able to render what he observed with accuracy and detail when he wanted to. But when real observation failed to confirm what he needed to be true in order to support his worldview-based beliefs about the evolutionary past and its parallels in the present, he opted to draw his own version of “reality.”

The ultimate excuse for Haeckel’s graphic concoctions has come from those who wish to honor what they see as his cognitively pure prescience coupled with a somewhat liberal view of the purpose of scientific illustration. “Haeckel’s own views on art stressed the primacy of interpretation over pure observation,”40 write Richardson and Keuck. They note that Haeckel’s own writings reveal that he knew early embryos of various species have a lot of differences. They assert that Haeckel therefore never intended for his pictures to depict his actual observations but rather to show what he deemed to be “a true reproduction of the really existing natural produce.”41 And fabrications though some of these drawings clearly were, Haeckel intended them as support for his recapitulation theory. Yet because the authors of the study maintain that recapitulation theory is true so long as it is viewed in a certain way — one trait at a time, with allowances for traits that have disappeared over time — they believe “Haeckel’s embryo drawings are important as phylogenetic hypotheses, teaching aids — even scientific evidence” (emphasis ours).42

But Why?

What recapitulation believers still struggle with, however, is some reason recapitulation should be true. What evolutionary advantage would it have? If embryos really recapitulate their evolutionary past, what is the evolutionary advantage of anatomic structures that develop and ultimately don’t get used? Why would unused “gill slits,” for instance, stick around across the evolutionary time scales through organisms that did not need gills until they could evolve a non-respiratory purpose?

Some embryologic structures only serve temporary purposes in the embryo and then disappear or regress. If these represent footprints of an evolutionary past, why would structures that don’t get used in the mature organism persist purposelessly through millions of years of evolutionary history?

In an attempt to answer this question, some expand on Gould’s idea of “terminal addition,” proposing that successful earlier evolutionary innovations are not lost but allowed to keep functioning while new developments are added. To undo earlier developments before they have served their place-holding purpose in the newly evolving organism would disrupt subsequent add-ons. While this describes exactly what happens in a developing embryo whose development is directed by its DNA blueprint, however, how can mindless random evolution “know” it needs to keep a useless structure in place for millions of years?

Phylogeny and the Return of Haeckel

Haeckel’s diagrams do not represent observable embryologic reality, and Haeckel knew they didn’t when he made them. And he intended them — doctored though they were — to be data in support of his evolutionary ideas. He intentionally falsified scientific observations to use “embryonic resemblance as proof of evolution”43 and “recapitulation as proof of the Biogenetic Law.”44 Yet he receives praise for his insight into the evolutionary past and his ability to reconstruct the observable present to prove what evolutionists believe.

Rigorous comparative embryology confirms “there is no evidence from vertebrates that entire stages are recapitulated.”45 Thus, Haeckel’s claims about embryonic development are not supported by actual observation. Even if embryonic development did proceed as he claimed, of course, it would not prove anything about a hypothetical evolutionary past.

But that aside, why are evolutionary scientists and educators so keen to use inaccurate diagrams for “phylogenetic hypotheses, teaching aids, and evidence for evolution”? Why do Haeckel’s modern apologists strain at his work, repackaging it to show how it could be true so long as it is viewed a certain way, such as one trait at a time?

Embryology, because it outlines successful steps that produce fully functional, mature organisms, tells the evolutionist what to look for. And because whole organisms don’t often fill the needs of the evolutionary story, evolutionists can now justify tracing single traits through deep time and seeking parallels in embryology. A fossil that seems to possess a trait in any of the ways it appears in an embryological developmental sequence can be claimed as a representative of its evolutionary sequence and assigned its spot in history.

If fossils seeming to fit the stepwise nature of different embryological stages can be found, they are lined up as evidence for evolution. But fossils do not demonstrate evolutionary transitions. Neither do embryologic stages. Yet by claiming that both actually do represent evolutionary sequences, evolutionists obtain visually compelling evidence and tie it together through a comforting knot of circular reasoning.

The controversy about the evolutionary origin of the turtle shell illustrates both of these points. Evolutionists have long debated the origin of the turtle shell. Until recently, all the turtle fossils found had been fully equipped with modern-appearing shells. Therefore, evolutionists have debated whether the shell evolved over millions of years by following the sequence seen inside the turtle egg or whether it evolved as a modification of external scales.

Now that two varieties of turtle with seemingly less developed parts of the shell have been identified, evolutionary researchers have noted that these shell variations more or less mirror shell developmental stages in the embryo. They therefore are asserting that turtle embryology predicted those forms successfully, proving on the one hand that those turtles are genuine transitional forms and on the other hand that ontogeny of turtle shells really does recapitulate phylogeny.46

In reality, no evolution from non-turtles is seen here, only two varieties of turtles. What these turtle fossils reveal is not a series of non-turtles evolving into turtles but just varieties of turtles. Mutations alter genetic information, and it is likely that these two extinct turtles are merely variations that developed from the original turtle kind God created about 6,000 years ago.

Finally, as teaching aids, teachers, and textbook manufacturers can now once again return in good conscience to teaching the mantra, “ontogeny recapitulates phylogeny,” that is — those that ever actually stopped in the first place. For many who accept evolution as unquestioned fact, any evidence that can be used to indoctrinate the young or the gullible is acceptable, even fraudulent concoctions from a man who was in the habit of manufacturing whatever counterfeits and forgeries he needed in order to promote evolution with the evangelistic zeal of a missionary.

Thus, despite their inaccuracies, Haeckel’s sometime critic-turned-defender concludes, “Haeckel’s embryo drawings are important as phylogenetic hypotheses, teaching aids — even scientific evidence. . . . The drawings illustrate embryonic similarity, recapitulation, and phenotypic divergence.”47

Recapitulation’s Future

Just because something is proven false, like recapitulation theory, doesn’t mean people are persuaded. These controversies can be expected to continue, not because there is proof that all life evolved from simpler ancestral forms, but because there is a popular widespread worldview-based belief in molecules-to-man evolution.

Believing that life must be explained as the product of natural evolutionary processes, evolutionary scientists must seek natural explanations wherever they can. Yet embryonic development is observable, and evolutionary phylogeny is not. Their supposed parallelism and the notion that such parallelism would constitute evolutionary proof are popular and powerful lies.

The observable wonders of embryology — surely a showcase of God’s design — were hijacked by Haeckel and continue to be much too valuable components of the evolutionary toolkit to relinquish. Recapitulation has therefore been resurrected and repackaged to teach and to convince. Haeckel’s “liberties” are excused with a nod that would never be extended to any modern scientist who faked his findings.

Recapitulation theory will doubtless continue to serve a prominent place in classrooms and on television documentaries aimed at convincing the public of the “obvious” truth of evolution. Moreover, as illustrated by the case of the turtle shell, highly trained evolutionary scientists, seeking to answer not “whether” things evolved but “how,” will find recapitulation theory to be a convenient tool to provide the circular reasoning to justify the theory of the moment.

The New Answers Book 4

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  1. A theory in science usually has little if anything against it. In light of this, recapitulation is more like a failed hypothesis since it has so much against it. But since this is the recognized terminology, we will continue to call it a theory in this chapter for the sake of understanding.
  2. M. Richardson and G. Keuck, “Haeckel’s ABC of Evolution and Development,” Biological Reviews of the Cambridge Philosophical Society 77 no. 04 (2002): p. 495–528.
  3. “Feedback: Embryo Protection” Answers in Genesis (July 22, 2011),
  4. Richardson and Keuck, Biological Reviews of the Cambridge Philosophical Society, p. 495–528.
  5. Ernst Haeckel, Natürliche Schöpfungs-geschichte (Germany, 1868; published in English in 1876 as The History of Creation.
  6. M. Richardson et al., “There is no highly conserved embryonic stage in the vertebrates: implications for current theories of evolution and development,” Anatomy and Embryology 196 no. 2 (1997): 91–106.
  7. Richardson and Keuck, Biological Reviews of the Cambridge Philosophical Society, p. 495–528.
  8. Ibid.
  9. Ibid.
  10. Stephen Jay Gould, “Abscheulich! (Atrocious!),” Natural History, 109 no. 2 (2000): p. 44–45, quoted in “Revisiting Those Pesky Embryo Drawings — Evolution News & Views,”
  11. Richardson and Keuck, Biological Reviews of the Cambridge Philosophical Society, p. 495– 528.
  12. Richardson et al., Anatomy and Embryology, p. 91–106.
  13. Stephen Jay Gould, Natural History, p. 44—45.
  14. Ernst Haeckel, Anthropogenie oder Entwickelungsgeschichte des Menschen. Keimes- und Stammesgeschichte (Engelmann, Leipzig, 1903); quoted in Michael Richardson and Gerhard Keuck, “A Question of Intent: When Is a ‘Schematic’ Illustration a Fraud?” Nature 410 no. 144 (2001).
  15. Ibid.
  16. Richardson et al., Anatomy and Embryology, p. 91–106.
  17. Ibid.
  22. E. Pennisi, “Haeckel’s embryos: fraud rediscovered,” Science 277 (1997):1435. Quoted in
  23. Time, November 11, 2002, article/0,9171,1003653,00.html. BROKEN LINK
  24. “Current Textbooks Misuse Embryology to Argue for Evolution,” Evolution News Views,
  25. Available online at
  26. See “Vestigial Hiccups, Folding Fish-eyes, and Other Fables: Our Fishy Forebears . . . Again!” at
  27. Stephen Jay Gould, Ontogeny and Phylogeny (Cambridge, MA: Belknap Press, 1977), p. 7.
  28. Ernst Haeckel, The History of Creation [translation of the 8th German edition of Natürliche Schöpfungsgeschichte], ed. E. R . Lankester) London: Kegan Paul, 1892), quoted in Richardson and Keuck, “Haeckel’s ABC of Evolution and Development,” Biological Reviews of the Cambridge Philosophical Society, 77 no. 04 (2002): p. 495–528.
  29. Ernst Haeckel, Anthropogenie oder Entwickelungsgeschichte des Menschen, quoted in Richardson and Keuck, “Haeckel’s ABC of Evolution and Development,” Biological Reviews of the Cambridge Philosophical Society, 77 no. 04 (2002): p. 495–528.
  30. Sylvia Mader, Biology, 9th ed. (New York: McGraw-Hill, 2007), p. 97.
  31. Henry Morris, The Long War Against God (Ada, MI: Baker Book House, 1989), p. 139.
  32. Ernst Mayr, “Recapitulation Reinterpreted: The Somatic Program,” Quarterly Review of Biology, 1994.
  33. J. Clune et al., “Ontogeny Tends to Recapitulate Phylogeny in Digital Organisms,” The American Naturalist, 180 no. 3 (2012): E54–E63.
  34. Ibid.
  35. Richardson and Keuck, Biological Reviews of the Cambridge Philosophical Society, p. 495–528.
  36. Ibid.
  37. Ibid.
  38. Ibid.
  39. Ibid.
  40. Ibid.
  41. Ernst Haeckel, Kunstformen der Natur, Bibliographisches Institut (1904), Leipzig und Wien; quoted in Richardson and Keuck, “Haeckel’s ABC of Evolution and Development,” Biological Reviews of the Cambridge Philosophical Society, 77 no. 4(2002): p. 495–528.
  42. Richardson and Keuck, Biological Reviews of the Cambridge Philosophical Society, p. 495–528.
  43. Ibid.
  44. Ibid.
  45. Ibid.
  46. “Turtle in the Gap,” Answers in Genesis (June 29, 2013),
  47. Richardson and Keuck, Biological Reviews of the Cambridge Philosophical Society, p. 495–528.


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