Tag Archives: Biology

Hard and soft transitional forms in the fossil record

Casey Luskin writes about it at Evolution News. (I removed all his links from the excerpts)

Excerpt:

Another good example is what the principal blogger covering human origins at BioLogos, Dr. James Kidder, did last year did in a series on human origins. His series is a good read and quite a competent presentation of the standard Darwinian evolutionary view of human origins — which no doubt reflects Dr. Kidder’s extensive training and experience with this issue. But it accedes 100% to the standard Darwinian story of human origins with essentially no critical analysis whatsoever. But how solid is the evidence behind Dr. Kidder’s view, and are there credible paleoanthropologists who doubt key parts of the orthodox story?

Here’s ONE of the problems that Luskin writes about:

Dr. Kidder’s BioLogos post tried to argue that I misunderstand the meaning of “transitional fossil.” This is a common and characteristically unfounded charge from Darwinian evolutionary biologists. They make the accusation because it takes the focus off the problems the fossil evidence poses for Darwinian evolution, and puts it on Darwin-critics. Advocates of Darwinian evolution also redefine what counts as “transitional,” so that the term becomes nearly meaningless. Here’s what’s going on:

We see that the phrase “transitional form” is used in two different ways. The “soft” definition of “transitional” implies that an organism merely needs to bear features that are representative of a potential intermediate — even if the fossil itself was not a direct transitional form. Under the hard definition of “transitional form,” a stronger claim is made that this organism actually was a real-life lineal intermediate between two taxa, a direct transitional form.

As evidence that this soft/hard distinction is used, for example, when some early tetrapod tracks were first reported in early 2010, Nature‘s Editor’s Summary said: “The finds suggests that the elpistostegids that we know were late-surviving relics rather than direct transitional forms, and they highlight just how little we know of the earliest history of land vertebrates” (emphasis added). The qualified term “direct transitional form” is a nod to the writer’s understanding that there is in fact a “hard” definition of a transitional form, and a “soft” definition, and that some fossils don’t meet the hard definition. What some people call a “transitional form” isn’t necessarily a “direct transitional form.”

So are there direct transitional forms in the hominid fossil record?

If you define “transitional form” in a soft enough way, so that neither temporal placement nor phylogenetic relationship matters any more, then it becomes very difficult to disprove claims that a fossil was “transitional.” It’s a wily rhetorical tactic, designed to make Darwin-skeptics look ignorant while simultaneously taking the focus off the lack of actual (e.g. hard) transitional forms in the fossil record. Dr. Kidder complains that ID proponents define such forms “in such a way that none could ever be found,” when in reality it’s Darwinian evolutionists who define transitional fossils so that they must, by definition, be found in abundance–even if they weren’t necessarily part of an evolutionary transition. Thus we see the Nature blogger quoted above saying absurd things like “every newly discovered fossil of a creature we didn’t know of before IS a missing link.” Or, we see Dr. Kidder making the less-absurd (though similarly inspired) claim that “[t]he human fossil record, in fact, is replete with transitional forms” as well as:

Transitional fossils in the human fossil record are distinguished at both the genus and species level. This group includes the extinct genera Ardipithecus andAustralopithecus and the current genus Homo.

Kidder would have no troubling finding some authorities who agree with him. But there are also credible authorities who disagree — especially with regard to those specific fossils. For example, in my series we’ve seen there are credible authorities who believe that “one of the most critical” areas of the human fossil record lacks transitional forms–specifically, “the transition fromAustralopithecus to Homo.”

Likewise, my series has also cited authorities who would disagree with Dr. Kidder’s claim that Ardi “was advanced in the human direction,” in the sense of developing bipedal locomotion, and who would sharply dispute his assertion that Ardi represents “a phenomenal example of a transitional form in the human fossil record.” Other experts would dispute the claim advanced by Kidder that the australopithecines show clearly “transitional characteristics.” In particular, many doubt theclaim that Lucy’s morphology was “perfectly intermediate between the ape position and the human position.”

Indeed, even Kidder admits: “Unfortunately, the path from Australopithecus to early Homo is shrouded in mystery, with no clear hominin form considered decisively to be the progenitor.” True! But then why does Kidder feel the need to so completely capitulate to the view that humans evolved from Australopithecus? He claims that ID proponents take it as an “article of faith” that transitional forms don’t exist, but it seems that some Darwinian evolutionary scientists take it as an “article of faith” that they do exist, and that the standard Darwinian story of human origins is true.

My point is not that Dr. Kidder is unequivocally wrong or that he’s uninformed. Hardly. He’s welcome to hold and express his opinion, and his series is a highly competent presentation of the standard Darwinian evolutionary account of human origins. Rather, I want to note that the standard story of human evolution — to which BioLogos’s principle blogger on this topic fully capitulates — is not the only scientifically credible position out there. When you dig into the technical literature, many parts of the standard story turn out to be based upon very weak evidence. In short, there are strong scientific reasons to dispute the claim that humans evolved from ape-like precursors. Is it acceptable to point this out?

It seems to me that whoever makes a claim about how we got here has the burden of proof. Both sides are making claims, so both sides have to shoulder the burden of proof. Our side had made claims about what would be found in the human genome for years, and we were vindicated recently with research published in Nature. Can the other side do that?

I recommend reading the whole article. There are good links in there to other things that Luskin has written on this topic, and links to the research he uses in his arguments as well. There’s also a new book out now on human origins that presents more evidence on both sides of this debate.

A parent’s guide to intelligent design and science education

An excellent PDF report prepared by the Discovery Institute’s Center for Science and Culture.

Here are the contents:

Introduction

  • Part 1: What Is Intelligent Design?
  • Part 2: What Is Evolution?
  • Part 3: What are the Scientific Problems with Neo-Darwinian Evolution?
  • Part 4: How Can Parents Influence Evolution-Education in Local Schools?
  • Part 5: What is Theistic Evolution?
  • Part 6: What Can Parents do to Support Intelligent Design?
  • Part 7: Basic Tips for Parents and Students
  • Part 8: Recommended Resources

First, there’s a definition of intelligent design: (the thing that people in the news media never define correctly!)

Intelligent design (“ID”) is a scientific theory which holds that some features of the universe and living things are best explained by an intelligent cause rather than an undirected process such as natural selection. ID theorists argue that design can be inferred by studying the informational properties of natural objects to determine if they bear the type of information that, in our experience, arises from an intelligent cause.

Proponents of neo-Darwinian evolution contend that the information in life arose via purposeless, blind, and unguided processes. ID proponents contend that the information in life arose via purposeful, intelligently guided processes. Both claims are scientifically testable using scientific methods employed by standard historical sciences. ID is based upon the claim that there are “telltale features of living systems and the universe which are best explained by an intelligent cause.”

Scientists investigating ID compare observations of how intelligent agents design things to observations of phenomena whose origin is unknown. Human intelligent agents provide a large dataset for studying the products of the action of intelligent agents. Mathematician and philosopher William Dembski observes that “[t]he principal characteristic of intelligent agency is directed contingency, or what we call choice.” When “an intelligent agent acts, it chooses from a range of competing possibilities” to create some complex and specified event. Dembski calls ID “a theory of information” where “information becomes a reliable indicator of design as well as as a proper object for scientific investigation.” ID seeks to find in nature the types of information which are known to be produced by intelligent agents, thus inferring a prior action of intelligence.

The type of information which indicates design is generally called “specified complexity” or “complex and specified information” (CSI). Dembski suggests that design can be detected when one finds a rare or highly unlikely event (making it complex) that conforms to an independently derived pattern (making it specified).

Intelligent design looks at features of nature, like cosmic fine-tuning and DNA, and infers an intelligent cause because of the nature of the effect. Information is best explained by an intelligence. Computer programs are best explained by an intelligence. Blog posts are best explained by an intelligence. Cross stitched art is best explained by an intelligence. Intelligence can create complex things that are composed of simple parts that are sequenced together in such a way that they have meaning and purpose that is independent of the properties of the components themselves.

Here’s a good video explaining intelligent design applied to biological information in proteins and DNA: (suitable for complete beginners)

For anyone who is looking for a good basic book on intelligent design, I recommend “The Politically Incorrect Guide to Darwinism and Intelligent Design” by Johnathan Wells. He holds a Ph.D in biology from the University of California at Berkeley. The best intermediate book on intelligent design is Stephen Meyer’s “Signature in the Cell“. He has a Ph.D in the philosophy of science from Cambridge University. The best advanced book is Michael Behe’s “The Edge of Evolution“. He has a Ph.D in biochemistry from the University of Pennsylvania. For Christians looking to understand the relationship between science, evolution and monotheism, I recommend “God and Evolution” edited by Jay Richards. He has a Ph.D in philosophy and theology from Princeton University.

Stephen C. Meyer and Keith Fox debate intelligent design and evolution

From Justin Brierley’s “Unbelievable” podcast.

Details:

Stephen Meyer is a leading proponent of Intelligent Design who directs the Centre for Science and Culture at the Discovery Institute in Seattle. His most recent book “Signature in the Cell” claims to show that the DNA code is the product of intelligent mind, not naturalistic processes. Keith Fox is Professor of Biochemistry at Southampton University. He chairs the UK Christians in Science network but disagrees strongly with ID. They debate how life could have originated and whether design is allowed as an explanation in science.

The MP3 file is here.

Summary: (stuff in italics is my snarky paraphrase)

Meyer:

  • background and how he got interested in intelligent design
  • his research focus is on the origin of life – the first replicator
  • summarizes the history of origin of life studies
  • authored the book “Signature in the Cell”
  • the DNA enigma: where did the information in DNA come from?
  • naturalistic explanations of the DNA information have failed
  • but intelligent agents are known to be able to produce information
  • the best explanation of the information in DNA is that an intelligent agent authored it
  • Meyer’s book was named by atheist philosopher of science Thomas Nagel as a Times Literary Supplement Book of the Year in 2010
  • why is design so controversial? Many people think that Darwin explained why nature appears design
  • the Darwinian view is that nature can create the appearance of design using mutation and selection
  • however, Darwinian mechanisms cannot explain the origin of the first living cell, it assumes replication, and the origin of life is about where the first replicator comes from

Fox:

  • Meyer’s argument is not about the evolution of life after the first cell
  • Meyer’s case for design is about the origin of life
  • naturalists do not know a naturalistic explanation for the origin of life
  • there are a number of naturalistic hypotheses for the origin of life, like the RNA-first hypothesis
  • maybe in a few years one of them will turn out to be correct
  • what intelligent design is arguing from a gap in our current naturalistic knowledge to infer that God intervened in nature

Meyer:

  • that’s not what intelligent design is at all
  • the approach ID theorists use is the inference to best explanation
  • you evaluate all explanations, non-intelligent causes and intelligent causes
  • you prefer the best possible explanation
  • we know that minds are capable of producing information just like the information we find in DNA

Fox:

  • living cells replicate, so they have the ability to introduce mutations as they replicate and then some of those mutations can be selected
  • so maybe the process of replicating that living cells do created the first living cell
  • maybe the first living cell created itself, X brought X into being, self-creation, what’s irrational about that?

Meyer:

  • the issue is the origin of life – where did the first living cell come from?
  • you cannot appeal to the operations that a living cell can perform to explain the origin of the first living cell
  • there was no first living cell operating before the first living cell
  • there was no replication, mutation or selection before the first living cell
  • in fact, in my book I show that there is no known naturalistic mechanism that is able to produce the information needed for the first living cell
  • nothing can create itself, that is self-contradictory
Fox:
  • Well, you are just saying that because something is complex that God did it
Meyer:
  • Sadly, no. What I actually said needed to be explained was the information, not complexity
  • And we know from software engineering that the process of adding information to code is performed by programmers
  • in the absence of any adequate naturalistic explanation for information, we are justified in taking the explanation that we are familiar with – namely, intelligent agency – based on our uniform, universal experience of what causes information
Fox:
  • well, maybe we can appeal to the mutation and selection in existing living cells to explain the origin of the first living cell
  • maybe there were living cells before the first living cell, and then these other living cells created the first living cell
Meyer:
  • we can’t keep invoking mutation and selection when those processes are not operating prior to the origin of the first living cell
Fox:
  • well maybe some bare-bones self-replication molecule was a precursor to the first living cell
Meyer:
  • even to generate very limited replicator would require a large amount of information
  • the argument I am making is – where does the evolution come from?
Fox:
  • well, maybe we will think of an explanation for information that is naturalistic in 20 years
  • we’ve thought of explanations to things that were NOT information before
  • so maybe we will be able to think of something to explain information based on our ability to explain NOT information before

Moderator: Change topics: the Dover decision

Meyer:

  • the Discovery Institute opposed the policy that causes the trial
  • the wording of the statute was poor
  • the judge was completely wrong in his decision
  • young earth creationists used the phrase “intelligent design” to cover their agenda
  • intelligent design is an inference using the normal methods of science
Fox:
  • intelligent design is a science stopper because it stops looking for a naturalistic explanation
  • everything in nature must have a naturalistic explanation
  • everything has to be explained using matter and time and chance
  • it just has to be that way!!!!
Meyer:
  • well, what luck would you have explaining an effect like Mt. Rushmore?
  • can you explain that using matter,time and chance?
  • Mt. Rushmore was the product of intelligence, not wind and erosion
  • similarly, there is information in the cell, and we know that intelligence causes information
Fox:
  • So you are saying that we don’t understand and therefore an intelligence is necessary?

Meyer:

  • no I am saying we DO understand and we are making an inference based on that understanding
  • you are the one who is insisting on a material explanation because you pre-suppose materialism
  • we know that minds have causal powers, and we can infer mind as an explanation from information
Fox:
  • well nature is a seamless chain of material causes and effects
Meyer:
  • agents can act without violating the laws of nature
  • even humans can act as intelligent agents to create information in books, and they don’t violate the laws of nature
  • intelligent causes are real, and they explain effects in nature
Fox:
  • you’re trying to impose on science something to do with meaning and purpose
Meyer:
  • no that’s not what we’re doing, we’re inferring from from the fact that we ourselves are known causes of information to the fact that an intelligence cause is the best explanation for information in the cell
Fox:
  • but I am a materialist, I need a materialist explanation
Meyer:
  • mind IS an answer to the how question
  • we infer to mind in many other scientific disciplines, like cryptography, archaeology, etc.
  • a materialist might accuse an archaeologist of engaging in a “scribe-of-the-gaps” argument, but the best explanation of an artifact with information is a scribe
  • we are inferring that mind is the cause from the nature of the effect: information
Moderator: is it appropriate to call DNA “information”

Fox:

  • well DNA is just a molecular polymer, any reference to information is just by analogy
Meyer:
  • DNA is a molecular polymer, but it also exhibits the property of specified complexity
  • the arrangement of bases, which function as machine instructions in a software program, for performings task in the cell
  • we have observed that the property of specified complexity always comes from an intelligence
Fox:
  • well, maybe there are other sequences that would work, so maybe it’s really not uncommon to develop functioning sequences by chance alone, without an intelligence
Meyer:
  • you can measure how precise the functional specificity is in DNA and proteins

Moderator: is Shannon information the same as functional information

Meyer:

  • Shannon information refers to the sequences of digits or symbols that do not necessarily have any function, i.e. – a four character string QSZX has as much Shannon information as WORD. However, only the latter is functional against the pattern of the English language. There are arrangements of DNA bases and amino acids that have the same number of symbols/characters as a functional sequence would have, but they have no biological function – they do not exhibit specified complexity
Fox:
  • Well, maybe there are lots and lots of sequences of DNA and proteins so that it is fairly easy to get a functional one by chance

Meyer:

  • DNA sequences that are functional are extremely rare, protein sequences are even more rare
  • this is not my opinion, this is what the research shows – functional protein sequences are rare
Fox:
  • well maybe there are other functional sequences that are occur before the first functional sequence that are precursors to the first functional sequence
  • maybe there are billions of years of replication, mutation and selection before the first replication, mutation and selection

Meyer:

  • you can’t get to the first selectable functional sequence by appealing to precursor selectable functional sequences – there are no selectable functional sequences before the FIRST one
  • you have to get the first selectable functional sequence by chance alone, because there is nothing to mutate or select before the first replicator
  • the chance hypothesis has been rejected because the minimal amount of information for the simplest replicator is too high to get by chance alone, given the resources, including time, that are available

Moderator: Keith are you confident that naturalism will be able to substantiate these naturalism-of-the-gap speculations that you offer in response to Meyer’s actual science that we have today? 

Fox:

  • well, it is hard to know for sure because it was just a fluke event
  • but there’s nothing irrational or unscientific or miraculous about it – the fluke would have a material explanation
  • there is nothing that we can detect that would implicate God, my speculations about a fluke which I cannot observe or measure or test would all be compatible with an atheistic worldview that omits God as a causal entity

Meyer:

  • where are those material processes that could account for this fluke then?
  • the whole point of this argument is that the information in DNA transcends the material components in the sequence
  • it’s the arrangement of the material parts/letters/characters/symbols/instructions that needs to be explained
Fox:
  • Well, I just have a different philosophy of science that rules out intelligent causation a priori

Meyer:

  • Yes, that’s the difference between us – you pre-suppose that all explanations of natural phenomena must exclude intelligent causes

There is a bit more where Meyer talks about how parts of the cell are implementations of various design patterns (Gang of Four design patterns) that are used by software architects who design software.

Find more posts on Stephen C. Meyer here.