Primer: ‘Sudden Appearance’

This is Part II in a series of four posts in which TFN Insider had university scientists analyze problematic changes the State Board of Education made to science curriculum standards for Texas public schools in 2009. This year publishers will submit — and the state board will approve or reject — instructional materials based on these flawed standards. The following entry examines the current version of Texas Essential Knowledge and Skills (7)(B), which reads as follows

(7)  Science concepts. The student knows evolutionary theory is a scientific explanation for the unity and diversity of life. The student is expected to:

(B)  analyze and evaluate scientific explanations concerning any data of sudden appearance, stasis, and sequential nature of groups in the fossil record;

(Other entries in series: TEKS (3)(A) — All Sides of Scientific Evidence; TEKS (7)(G) — Complexity of the Cell; TEKS (9)(D) — Self-Replicating Life)


This standard was a new addition to the Texas science TEKS in 2009. It originated at the January 22, 2009, state board meeting in an amendment proposed by Don McLeroy, R-Bryan, a self-identified young earth creationist. The original wording of McLeroy’s amendment – approved by the board in January – was as follows:

(B) analyze and evaluate the sufficiency or insufficiency of common ancestry to explain the sudden appearance, stasis and sequential nature of groups in the fossil record;

At the March 27, 2009, board meeting, Lawrence Allen, D-Houston, moved to strike this standard entirely. In a final appeal to preserve his proposal, McLeroy stated that the purpose of his standard was to argue against:

“…the idea that all life is descended from a common ancestor by the unguided natural processes.

Despite McLeroy’s protestations, Allen’s amendment to strike the standard prevailed by an 8-7 vote, and it was removed from the standards. However, another member of the board’s anti-evolution faction, Cynthia Dunbar, R-Richmond, immediately offered new “compromise” language. An amendment by Bob Craig, R-Lubbock, slightly revised Dunbar’s “compromise.” Dunbar’s wording – as amended by Craig – was approved by a vote of 13-2. This compromise language was the final version adopted by the board.

Scientific and Pedagogical Problems with Standard

By Dr. John Wise, Research Associate Professor of Biological Sciences and Adjunct Associate Professor of Biological Sciences at Southern Methodist University in Dallas

Language referencing “sudden appearance” appears commonly in – and is closely associated with – the intelligent design movement.1 The inclusion of the expectation that students “analyze and evaluate scientific explanations concerning any data of sudden appearance … in the fossil record” parallels the major thesis of a book promoting intelligent design/creationism written by five members affiliated with the Discovery Institute’s Center for Science and Culture.2 Essentially the book, Exploring Evolution, promotes the hypothesis that the Cambrian Explosion, a geological period about 530 million years ago that revealed a great radiation of new animal body forms in the fossil record, can not be explained by current evolutionary science. The book extends this thesis by requiring that an intelligent, supernatural agent was required to create the new animal body forms. None of these hypotheses are supported by scientific evidence (as explained below).

The intelligent design/creationism thesis that the Cambrian Explosion occurred too “suddenly” to be explained by modern biological science completely ignores  a number of recent advances made in the science of evolutionary development that describe how animal bodies are made in a genetically modular way, thereby enabling rapid evolution.3 These intelligent design arguments also ignore many pre-Cambrian organisms that show relatedness to Cambrian organisms (see, for example, endnote 4).  In short, misleading claims about the Cambrian Explosion made in the intelligent design community have been specifically refuted on many detailed grounds and in many different places.5,6,7

This part of TEKS (7)(B) should therefore be deemed as an attempt to open the Texas public school educational system to old, refuted, religiously based, nonscientific intelligent design arguments. 
Likewise, the expectation that students analyze and evaluate scientific explanations of “stasis, and sequential nature of groups in the fossil record” is another use of language that can be traced to biased publications from anti-evolution, intelligent design/creationism proponents. The word “stasis” is used to describe the observation that fossil forms appear fully formed in the fossil record and remain relatively unchanged for long periods of time. In fact, these types of observations are fully compatible with evolutionary science. What other than fully formed organisms could be fossilized, for example? In addition, species that are well-adapted and exist in relatively stable environments would in many cases have the advantage of superior numbers over any organisms that would try to replace them. The predominant species would then be expected to dominate the fossil record over that period of time where its numbers predominated.

That fossils of transitional species (those species that are intermediate in characteristics between more widely separated organisms) are rare is a simple logical consequence of the time it takes the transition to occur versus the time of existence of the ancestor and descendant species. If the ancestor and then later the descendant species are well-adapted and are lucky enough to exist in stable environments, their total time on Earth can be very long. The transitions on the other hand can occur relatively quickly (in geologic time). The chance of finding a fossil of one of the transitional intermediates can therefore be low compared to finding a fossil of the stable ancestor or stable descendant species. Even though transitional fossils are rare and difficult to find, many transitional fossils species have been discovered by paleontologists. The existence of transitional fossils, as well as the general concept which these fossils support — namely, the sequential nature of descent from common ancestors — is so greatly supported by real scientific evidence that the vast majority of biological scientists and paleontologists accept these principles as fact.

There is a clear danger that the “stasis, and sequential nature” part of TEKS (7)(B) will be used to introduce discredited, scientifically falsified accounts from intelligent design/creationist publications that species appear in the fossil record without any transitional fossil evidence. Examples of these types of discredited arguments in intelligent design publications include the textbook supplement Of Pandas and People, which was the book at the center of the Dover trial8, and Icons of Evolution9, which pursues the discredited idea that major phylogenic groups in biology arose without any connection through descent from a common ancestor. In the age of modern biology, the hypotheses that fossil transitions are not evident in the fossil record as presented in Pandas and Icons has been fully refuted by many legitimate fossil transition discoveries. These real discoveries fully support modern evolutionary theory.

Unfounded doubts about the cornerstone of evolutionary theory, namely descent from common ancestors, introduced into students’ learning expectations via the use of intelligent design/creationism language like “sudden appearance” and “stasis, and sequential nature” have absolutely no place in biology classrooms or biology textbooks in Texas or anywhere else.

How Publishers Can Responsibly Address Standard

By Dr. Ben  Pierce, Professor of Biology and holder of the Lillian Nelson Pratt Chair at Southwestern University in Georgetown

To meet this new standard, publishers need not and should not introduce creationist arguments, as they do not meet the requirement that students analyze and evaluate “scientific explanations.”

One way for publishers to satisfy this new standard is to include a discussion of evidence for and against the theory of punctuated equilibrium. This idea, first proposed by evolutionary biologists Niles Eldredge and Stephen Jay Gould in 1972, is a scientific explanation for long periods of no evolution (stasis) followed by the sudden appearance of new organisms in the fossil record.10

Punctuated equilibrium proposes that major evolutionary change occurs when new species arise and that, between these speciation events, many organisms undergo little change. Evolutionary biologists have long debated whether evidence supports or refutes the theory of punctuated equilibrium. The fossil record of some organisms does indeed suggest a pattern of stasis followed by bursts of rapid evolution,11 but this pattern is not seen in other organisms.12 A review of 58 different studies that examined the theory of punctuated equilibrium across a range of organisms and geological periods concluded that sometimes evolution is gradual and sometimes punctuated — neither pattern is characteristic all of evolution.13 There is considerable disagreement over what processes are responsible for stasis in evolution.14


1 accessed on February 18, 2011 at the Discovery Institute’s Center for Science and Culture webpage, “The Theory of Intelligent Design: A Briefing Packet for Educators” – see, for example, page 15.
See Discovery Institute website, (accessed Feb. 18, 2011).
3 Carroll, S.B. 2005 Endless Forms Most Beautiful: The New Science of Evo-Devo, Norton and Co. New York.
4 Derek E. G. Briggs and Richard A. Fortey, 2005 “Wonderful strife: systematics, stem groups, and the phylogenetic signal of the Cambrian radiation” Paleobiology 31:94-112
5 A detailed analysis of fallacious “sudden appearance” arguments from the National Center for Science Education, (accessed Feb. 18, 2011).
A paleontologist’s response to fallacious intelligent design arguments about the Cambrian Explosion, (accessed Feb. 18, 2011).
A listing of problems with intelligent design/creationism’s claims about the Cambrian Explosion and other assertions, (accessed Feb. 18, 2011).
8 For a critique of the anti-evolutionary theory, pro-intelligent design Of Pandas and People’s treatment of the fossil record, see the National Center for Science Education (accessed Feb. 18, 2011).
9 For a critique of creationist-intelligent design Icons of Evolution, see the National Center for Science Education, (accessed Feb. 18, 2011).
10 Eldridge, N. and S. J. Gould.  1972.  “Punctuated equilibria: An alternative to phyletic gradualism.” In T. J. M. Schopf, ed. Models in Paleobiology.  Freeman, Cooper, and Company,San Francisco.
Jackson, J. B. C. and A. H. Cheetham. 1994. “Phylogeny reconstruction and the tempo of speciation in cheilostome Bryozoa.”  Paleobiology 20:407-423.
Chaline, J. and B. Laurin.  1986. “Phyletic gradualism in a European Plio-Pleistocene Mimomys lineage (Arvicolidae, Rodentia). ” Paleobiology 12:203-216.
Erwin, D. H. and R. L. Anstey. 1995. ” Speciation in the fossil record.”  In D. H. Erwin and R. L. Anstey, ed.  New Approaches to Speciation in the Fossil Record.  Columbia University Press, New York.
Futuyma, D. J.  1987.  “On the role of species in anagenesis.”  American Naturalist 130:465-473.

5 thoughts on “Primer: ‘Sudden Appearance’

  1. Given some sixty million years of evolution, what is “sudden”? A hundred thousand years can be pretty sudden.

    The creationist/intelligent design theories depend on finding fault in an intelligent evolving science based on the scientific method. As the field expands, the basis of criticism has to shift and with each shift loses consistency or, alternatively, relevance. By relying on perceived error, the creationist risks losing relevance and relegating religion to the outer regions. to disappear altogether.

    The salvation of religion as relevant needs to recognize that it was the result of the best minds at the time, seeking to resolve isssues facing life given the best information available. The moral judgements made in various religions often resemble those found in other eligions and codes of conduct, and should be vieeed in their practical conext.

    The Ten Commandments aren’t a bad set of rules to govern a society, establishing a rule that sets this code as the law for all. This is no different that what a legislature does in it’s code of laws. The value of the Ten Commandments (or other similar code) is it’s utility and validity as it relates to society. The burning bush and the tablet story is necessary to establish authority in a bunch of refugees wandering in the desert.

    By sticking to the Bible as science, risks losing the Bible and it’s several thousand years of successs as a practical set of example and rules for governance. Attempts at replacing the Bible with the worship of Reason as done in the Red Terror of the French Revolution, or of the Russian Revolution, or of the brief Thousand Year Reich, has had an awfully good record of success.

    From a scientific stand point ….

  2. Dr. Pierce: “One way for publishers to satisfy this new standard is to include a discussion of evidence for and against the theory of punctuated equilibrium. This idea, first proposed by evolutionary biologists Niles Eldredge and Stephen Jay Gould in 1972, is a scientific explanation for long periods of no evolution (stasis) followed by the sudden appearance of new organisms in the fossil record.”

    I think he is suggesting that the textbook publishers comply with the TEKS by using an example that is sure to make evolution look great and creationists/ID people look stupid. No extremist is going to buy off on that, especially not the extremists on the Texas SBOE. They will insist on content in which they PERCEIVE that evolution people will look stupid and creationist/ID people will look smart. You notice I said “PERCEIVE.” The truth of the matter is that the Texas SBOE will send back such ideas 40, 50, 60, or 70 times until they get the exact wording they want.

    Here is what I think the textbook people are thinking:

    Textbooks Executives: “We need a course of action that will bring us both salvation and absolution. You’re our lawyer Fred. What would you do?”

    Lawyer Fred:

    Well, from what you say, I gather that you want to sell as many textbooks as possible this year, without making the scientific public too angry at you and without making the Texas SBOE so angry that they will no longer buy their textbooks from you 10 years from now. This would be my legal strategy for you. In the first year, deliver to the demands of the creationist/ID people in your textbooks. The trick is to deliver in a way that will ultimately benefit your company, the scientific community, and public school science education. Here is how I propose to do it. My legal team will work with your in-house textbook development staff only (not the Texas SBOE) to craft the language in the textbooks in such a way that it will never stand a snowball’s chance in hell of passing a First Amendment test in federal court. In other words, we rig the textbooks to lose in federal court. Most of the creation/ID people are so stupid that they will never see what we are doing. In fact, because the language will cater so well to their religious prejudices, they will welcome it with open arms and approve the language with little consideration of its implications. This will assure your first year of textbook sales in Texas. The textbooks will then go to court, and the federal court decision will nullify the Texas TEKS and the resultant textbooks as an attempt to preach a particular religious viewpoint in public school science class. The Texas SBOE will be out of business. The loony tunes textbooks will be out of business. Real science will be back in business. Your company will follow up with the Texas SBOE by putting on a coprolite-eating grin and saying to them, “Well, we worked with you and you approved the textbooks, but it just didn’t work out the way we had hoped. Dang it!!! Life is just like that sometimes. Now, Ms. Lowe, I was wondering if you would like to take a look at our new line of textbooks for next year? They sure are dandy, and we feel certain that these will keep you out of trouble. Can we put you down for 3,000,000 books?”


  3. I disagree with Dr. Pierce’s response. The mechanics of punctuated equilibrium are very difficult to grasp. I’ve read some of the details on several occasions and am not keeping them straight — and I’m a layperson who is educated more than most about evolution. This issue cannot be addressed properly in the classroom. The creationist answers will come up, if the TEKS is ever addressed using the language of the TEKS, and those are the answers that will stick. I think Dr. Pierce is handing this one off to the creationists.

    Instead, textbooks should boldly address misconceptions about “sudden appearance, stasis, and sequential nature of groups in the fossil record.” It appears to me that doing so is the only way to actually satisfy the TEKS. Concrete examples should be explored in depth. Punctuated equilibrium will come up, but the assumptions that lead one from punctuated equilibrium to creationism are exactly those that support creationism. Address the false assumptions, and people will not assume that the simple creationist answers to the complex mechanics of punctuated equilibrium are the best possible answers.

  4. Joe Lapp: The mechanics of punctuated equilibrium are very difficult to grasp.

    Not really, if you look at it via the mathematics. Both favorable and purifying selection are governed by an exponential (more exactly: logistic) growth curve. The degree of the benefit dictates the exponential’s time constant (with detriment being a negative-value benefit). While large-benefit mutations are relatively rare, when they do happen their impact is immense and rapid.

    The hard part is keeping the time-scales straight. In terms of an organism’s reproductive life cycle, a thousand years is a long time; in terms of geology, a thousand years might be about 3 mm of rock.

  5. I, too, read “sudden appearance” and “stasis” as punctuated equilibrium arguments, not creationism/ID ones