Should "Darwin's Natural Selection Paradigm" be changed?
The demonstration of the inheritance of acquired immunological characteristics in general, would necessitate a grand revision of the neo-Darwinist view of the source of new genes. This is because neo-Darwinism holds that the only source of new genetic variation is random non-adaptive mutation in germline DNA and germline DNA is genetically independent of somatic DNA. If Steele et al are right, the soma-to-germline route would be an exceptional source of new genes for the germline and consequently neo-Darwinism needs to be updated in that respect.
Unfortunately the most straightforward evidence for the inheritance of acquired immunological characteristics is controversial and inconclusive. The indirect evidence is increasingly accepted by peer reviewed scientific journals (13).
Ironically, Darwin believed in inheritance of acquired characteristics! Darwin published his hypothesis of pangenesis as the last chaper of Variation in Plants and Animals in 1868. According to pangenesis, the basis of hereditary characters resides within tiny cellular particles called 'gemmules'. Gemmules then migrate from somatic to germ cells, where they collect to pass inherited characters to the next generation. Since gemmules become modified in somatic cells by conditions of life and the actions of organisms, acquired characters can be inherited! (25).
Natural selection would not become unnecessary by the hypothetical soma-to-germline route. If the inherited antibody sequences would become permanently incorporated into the germline, this would happen by virtue of both 'somatic selection' and natural selection. Because only the contribution to the fitness of the individual and its offspring would determine the long-term usefulness of those retro-genes. And the retro-pseudo-genes can only be useful if they are expressed! Steele is not opposed to natural selection (8) and as I see it the 'only' possible change to "Darwin's Natural Selection Paradigm" would be the addition of a mechanism specific to the immune system. So the subtitle of his book is too general: even if the soma-to-germline route would be proven, it would not follow that other organs do behave in the same way. It would not automatically be a general mechanism. As Stephen J. Gould said:
"If acquired characters are inherited only rarely and weakly, then Lamarckism might aid natural selection
in developing adaptation more quickly - a position advocatted by Darwin himself throughout the Origin.
But if acquired characters are inherited faithfully all the time, then natural selection will be overwhelmed and Lamarckism
becomes a refutation of Darwinism. Relative frequency determines the distinction." (24).
However, if the soma-to-germline route exists, I think it could have consequences for gene therapy in humans (3).
The evolutionary biologist John Maynard Smith (1998) is unaware of Steele's newer research, and mentions only far less interesting exceptions to the central dogma, but has an open mind to Lamarckism: "it is not so obviously false as is sometimes made out." (9). Steele rightly criticises Richard Dawkins(10) and Daniel Dennett's (11) condemnation of Lamarckism. They don't know the evidence.
Lamarck's Signature has a great educational value. The chapters on immunology are better written than those about the genetics of the immune system. There is a useful Glossary of terms for the non-specialist. Pseudo-genes and retrogenes (featured in the book title!) are not in the glossary and are not well enough explained to provide the necessary background knowledge. Lamarck's Signature deserves to be called 'the textbook of neo-Lamarckism'.
Lamarck's Signature. How Retrogenes Are Changing Darwin's Natural Selection Paradigm|
by Edward J. Steele, Robyn A. Lindley, Robert V. Blanden
paperback edition: 1999
| 1||The twin legacies of Lamarck and Darwin||1|
| 2||In the beginning there was RNA||25|
| 3||Why the immune system is so interesting||58|
| 4||The idea of 'clonal selection'||95|
| 5||Somatic mutation||125|
| 6||Soma-to-germline feedback||163|
| 7||Beyond the immune system?||187|
About the film 'Ted's Evolution' (.doc) by
the producers (2002).
The document has a list of people and publications.
The film was broadcasted in Australia (12 June 2003) and in Belgium
(links, meer info)
on 28 Dec 2003.
Patrick Fogarty (USA) injected mice with genes. The genes ended up in testis and eggs and in the offspring.
This is evidence for crossing the Weismann Barrier. I could not find any published papers about these findings.
Gabriel Dover (UK) was asked to comment on Ted Steele's findings:
"His theoretical premise is a howler. You have to understand
your enemy. He can't give the evidence of how you get from the body cells to the sex cells. He has not got a basic piece of
evidence". Remarkably, Dover himself defends an unorthodox evolutionary theory (see review on this site), therefore, I expected a more sympathetic or at least a fair hearing of Steele's work.
Corrado Spadafora (1989) "Sperm Cells as vectors for introducing foreign DNA into eggs: genetic transformation of mice",
1989, Cell 57, 717-723.
Elizabeth Simpson: The case of the midwife scientist. Int. J. Dev. Biol. 45: 513-518 (2001).
She is not in the film, but worked at the same time as Ted Steele in Medawar's lab in London during the 80's.
This publication contains a paragraph "Interlude with Lamarck" featuring Ted Steele. She concluded "we could find no evidence of inheritance of the acquired character of tolerance to transplantation antigens".
Publication in New Scientist 7 May 1981: "Lamarck and immunity: a conflict resolved" (London period of Steele).
Steele, E.J. (1979) Somatic Selection and Adaptive Evolution : On the Inheritance of Acquired Characters. First Edition.
It was probably the manuscript of this book that Steele send to the famous philosopher Karl Popper. Steele
received an encouraging note from Popper.
[box added Dec 2003, updated 11 Jan 2004]
- Roitt, Brostoff, Male Immunology, 1993, third Edition.
- Although there is a glossary (more than one) there is no definition of 'pseudogenes'.
- The implications of Steele's soma-to-germline feedback for the safety of somatic gene therapy in humans. by G. Korthof [updated: 14 Apr 2002].
- Roderic Page & Edward Holmes(2000) Molecular Evolution, p2. Ironically the HIV virus owes his high mutation rate to the sloppy work of reverse transcriptase; the same mechanism that Steele proposes as the cause of hypermutation of V(D)J genes.
- Later I found this: "After years of fighting HIV, the human immune system is like a closet full of clothes you can't wear. Crowded with useless antibodies and killer T cells with no targets, the bloodstream sports only last year's immunologocial fashions." Stephen Palumbi(2001) The Evolution Explosion, p117.
- Bob Koepp wrote (15-06-01): Actually, in the 1958 paper Crick stated explicitly that the CD meant that sequence information could not flow from proteins to nucleic acids. When reverse transcriptase was discovered in 1970, Crick wrote a short paper to explain that this discovery did not require any revision of the CD. See: feedback page. Later I found that Crick stated in 1957 that the transfer of information from protein to nucleic acid is impossible, Symp.Soc.Exp.Biol. 12, 138-163 (1957).
- There is a rather clear distinction between accepted knowledge and Steele's hypothesis. The exceptional rearrangements of the VDJ genes and the non-random distribution of mutations in that region (Wu-Kabat) are remarkable from a genetic point of view, but are present in the textbooks of immunology (see note 1).
- "On the contrary, the Darwinian idea will be shown to be essential to the 'Lamarckian concept' of a gene feedback loop."(page 6).
- John Maynard Smith(1998): Evolutionary Genetics, Second edition, page 8. The quote was already present in the 1989 edition.
- In Chapter 11 "Doomed Rivals" in The Blind Watchmaker(1991) on page 293-298 Dawkins explains why genes are not a 'blueprint' but a 'recipe'. This is an insightful analogy, everybody should read (again). However it's illuminating up to a point: as long as one looks at morphological characteristics of an animal, the analogy illuminates, but precisely when we are dealing with Steele's antibodies (where proteins themselves are units of function) his model breaks down. This is because there is a one-to-one relation between protein and DNA. This has the consequence that the RNA's of antibodies could be 'reverse engineered'. That's why Dawkins' blueprint/recipe analogy doesn't apply to Steele's antibody and antibody genes and consequently Dawkins criticism fails. However Dawkins seems to be right in claiming that Lamarckism doesn't explain adaptation.
- Daniel Dennett(1995) Darwin's Dangerous Idea, paragraph 2: "Three Losers: Teilhard, Lamarck and Directed Mutation", pages 320-324 of chapter 11.
- See the review of The neutral theory of molecular evolution on this site.
- However in the middle of a review of Lamarck's Signature one can find an email of an anonymous molecular biologist with an alternative, neo-Darwinian explanation of Steele's indirect evidence. However see Steele's reply (comment 4). It now appears that the molecular biologist withdrew his explanation.
- John Maynard Smith(1998): Evolutionary Genetics, Second edition, page 205.
- Mark Ridley(1996): Evolution, Second edition, page 181.
- Daniel Hartl & Andrew Clark(1997), Principles of Population Genetics, page 388-390.
- Wen-Hsiung Li(1997), Molecular Evolution, Chapter 12: 'Evolution by Transposition and Horizontal Transfer' ( a useful overview of jumping genes) and an online article about jumping genes: Jumping Genes Play Useful Role In Human Evolution. (the P element Kidwell has long studied in fruit flies, only jumps in germline cells.)
- This information is present in the textbook: Grauer and Li(2000), Fundamentals of Molecular Evolution, Second Edition, p336 : "If a gene is not transcribed within a germline cell, but only in specialized somatic cells, the creation of a retrosequence requires the RNA to cross cell barriers from the somatic cell to the germline cell. This can happen when an RNA molecule becomes encapsulated with the virion particle of a retrovirus and is then transported to the germline cell where it is reverse-transcribed [M. Linial (1987): "Creation of a processed pseudogene by retroviral infection", Cell 49:93-102]. I asked prof Steele for a reply. This is his answer [26 Feb 2001]. Look for entries transposition, retroposition, retrogenes, retro-pseudogene, processed retrogene in the textbooks.
- The human gene PDHA2, a testis specific gene, is an intron-less processed retrogene generated by reverse transcription from the mRNA of the X-linked PDHA1 gene. It has presumably evolved in response to the silencing of X-linked genes during spermatogenesis. Strachan & Read (2000): Human Molecular Genetics, p327. See further the work of Corrado Spadafora.
- Reverse transcription could be a relic of the transition from the RNA-world to the DNA-world. The acquisition of reverse transcriptase has made it possible to synthesize DNA. This is step 8 in the origin of life according to Anthonie W.J. Muller. See The origin of life in 9 steps.
- Leo Buss argues that in protists, fungi, plants and 19 of the 33 different animal phyla around today, the Weismann barrier can leak (Proc. Natl Acad. Sci. USA 80, 1387-1391 (1983)). In these organisms, somatic cells can become germ cells, and thus genetic changes acquired during development within the soma can become heritable.
- "Experts noted that they have suspected 'for decades' that a retrovirus could insert in the wrong place". Science, Vol 298, 5601, 13 Dec 2002, pp. 2113-2115.
- Steele's first publication was: R.M. Gorczynski and E.J. Steele(1981) "Simultaneous yet independent inheritance of somatically acquired tolerance to two distinct H-2 antigenic haplotype determinants in mice", Nature Vol 289 19 Feb 1981, p.678. This was accompanied by an editorial entitled "Too soon for the rehabilitation of Lamarck", (p.631) and followed in the 26 March issue (p.286) by a letter from K.W. Jones "Inherited tolerance?" proposing an alternative interpretation of the data. In 1984 Steele contributed to the book Evolutionary Theory. Paths into the future (1984) a chapter "Somatic selection of acquired characters".
- Stephen J. Gould (2002) The Structure of Evolutionary Theory, p.354. [ 29 Feb 2004 ]
- same book page 423. [ 5 Mar 2004 ]
- Relevant are Transposable elements (TE). There are two main classes of TE: DNA transposons, which act through a DNA intermediate and multiply by using the host cell's replication machinery, and retrotransposons,
which act through an RNA intermediate. The silencing and activation of TEs in the male and female germ lines can affect
genes that are involved in the RNA interference (RNAi) pathway. (NATURE Vol 443 5 October 2006 p.522.)
Could Steele misidentify germline specific Transposable retro-Elements active in the germline as soma-derived?
- The Central Dogma of Molecular Biology and Weismann's Barrier have been confused in the past.
The first defines the rules for information flow at the molecular level and the second, a cellular theory, prohibits somatic genetic information (RNA/DNA) being fed-back to germline DNA in germ cells. EJ STeele (2009).
Other books by E. J. Steele
- E. J. Steele (1979, 1981) 'Somatic Selection and Adaptive Evolution. On the Inheritance of Acquired Characters'. Univ. Chicago Press.
2d edition. 144 pages. info.
- Home page of Dr. Edward J. Steele with five representative publications. [This page was removed by the University of Wollongong on Feb 26 2001 ]. New location of homepage [4 March 2003].
- Professor Robert Blanden page with references of recent publications.
- Review by Laurence Hurst in: New Scientist 17 April 1999, page 60-61 (2 months after I published the above review). Prof Hurst is an evolutionary biologist and wrote a very critical review.
- However see: Letter to the Editor of Steele et al. which was not published by the New Scientist.
- Genetic Notes - Embarrassment of the neo-Darwinists. An invited comment by Steele et al in "The Independent" newspaper (London, UK) Saturday May 8 1999.
- What Is Lamarck's Signature? by Edward J. Steele and Robert V. Blanden (or this page for access without registration) on: "HMS Beagle" (Opinion). Posted June 11, 1999 Issue 56. "HMS Beagle" is a biweekly Webzine for biomedical researchers. (free registration required). The article was followed by a number of letters with a reply of Steele: Lamarck lives on (June 23 1999).
- 'The Other Evolutionist'. A review of Lamarck's Signature by Mark Parascandola, in Lingua Franca Online, Volume 9, No. 9 - December/January 2000.
- Signature tune of a scientific 'heretic', Launch of Lamarck's Signature in "Campus news" (with picture of Ted Steele).
- Robyn Williams, Radio National, speaks with Professor Ted Steele Sunday 01/11/1998 (transcript).
- 'Rethinking Darwin'. Jennifer Byrne, ABC Television, speaks to Professor Robert Blanden, co-author of Lamarck's Signature, 8/10/98 (a transcript).
- Laurence D. Hurst (1999) "Cut off their tails", New Scientist 17 April 1999, pp.60-61. Is a review of Lamarck's Signature. Hurst is a Professor of Evolutionary Genetics at the University of Bath. [added 4 Jan 2004]
- A review of Lamarck's Signature by Mark Hurst. (July 23, 1999).
- Lamarck's Revenge by Alan I Packer, American Scientist 05-06/1999 p274. (very short review of Lamarck's Signature)
- 'Experimental Lamarckism', Brian Hayes, American Scientist November-December 1999, Volume 87, No. 6. (cost-benefit analysis for Lamarckian inheritance).
- Robyn Williams speaks with Anthony Barnett (Emeritus Professor of Zoology) about Lamarck and evolution [2 Jan 2000]
and part 2 (transcripts).
- 'The Evidence for Lamarck', QUADRANT March 2000 No. 364 Vol XLIV Number 3 pages 47-56.
- This is an extremely useful and masterfully written summary for the general reader. Please note that Steele shows that Darwin accepted that acquired characters can be inherited! Furthermore Steel points out the difference between Weismann's dogma and the Central Dogma. [added: 1 Jan 2001]. Regrettably this article has been removed by the University of Wollongong. However it can be still be found via the cached page of google.com. . [16 mar 2001]. It can also be found here: http://beliefinstitute.com/article/evidence-lamarck
- There is a chapter of Steele in J.W. Pollard (1984) (ed) Evolutionary Theory. Paths into the future: "The somatic selection of acquired characters", chapter 9, pp.217-233.
- A review of Lamarck's Signature. (name of the author is not on the page).
- Lamarck Revisited. The Inheritance of Acquired Characteristics Gains Attention, January, 2001 (name of author is not on the page).
- The double helix and immunology by Gustav J. V. Nossal (2003) NATURE , VOL 421 , 23 JANUARY 2003. (illustrated, recommended).
- About the evolution of the immune system: Matthew N. Alder et al (2005) Diversity and Function of Adaptive Immune Receptors in a Jawless Vertebrate, 23 DECEMBER 2005 VOL 310 SCIENCE.
- Christian Biémont and Cristina Vieira (2006) "Junk DNA as an evolutionary force" Nature, Vol 443 5 October 2006. Important and good overview of transposable elements. 16 Dec 2006
- Rolff J. (2007) Why did the acquired immune system of vertebrates evolve? Dev Comp Immunol. 2007;31(5):476-82. 23 May 2007
- Babushok, DV et al (2007) 'A novel testis ubiquitin-binding protein gene arose by exon shuffling in hominoids, Genome Res 2007 Jul 10. ('...and the resulting chimera is then reverse transcribed and integrated into the genome by the L1 retrotransposon." "S5aL is transcribed specifically in the testis both in humans and chimpanzees...") 13 Jul 2007
- Edward J. Steele, Robert V. Blanden (2001) The reverse transcriptase model of somatic hypermutation, Philosophical Transactions of The Royal Society, Biological Sciences, Volume 356, Number 1405/January 29, 2001. 8 Jan 2008
- Ross Honeywill (2008) Lamarck's Evolution. Published by Pier 9. 8 Aug 2008
- E.J. Steele (2009) Lamarck and immunity: Somatic and germline evolution of antibody genes. Journal of the Royal Society of Western Australia, 92: 437–446, 2009. This is a review presented at the Darwin Anniversary Symposium in Perth in 2009. RSWA source.
- See for an up to date publication list: Profile of Edward J. Steele at the Research School of Biological Sciences. 8 Aug 2008
- Rewriting Darwin: The new non-genetic inheritance New Scientist, 09 July 2008 by Emma Young. 11 dec 2008
- Robyn A. Lindley (2010) The Soma: How our genes really work and why that changes everything! CreateSpace. Her husband is Ted Steele.
- Cédric Feschotte (2010) 'Virology: Bornavirus enters the genome', Nature 463, 39-40 (7 January 2010) 7 Jan 2010
"Some people might find it disquieting that a hefty 8% of human genetic material originates not from our vertebrate
ancestors but from viruses. The assimilation of viral sequences into the host genome is a process referred to as
endogenization. It occurs when viral DNA integrates into a chromosome of reproductive germline cells and is subsequently passed from parent to offspring. Until now, retroviruses were the only viruses known to generate such endogenous copies in vertebrates. But non-retroviral viruses called bornaviruses have been endogenized repeatedly during mammalian evolution. The finding unveils bornaviruses as a potential cause of mutation and also as an unforeseen source of genomic innovation".
In this article 'Weismann Barrier', 'Lamarckian inheritance', 'horizontal gene transfer' are not used. In stead: 'endogenization' is used. In fact, what is happening here is that exogeneous DNA is integrated in germline DNA and vertically transmitted to the next generation.
- Oded Rechavi (2011) 'Transgenerational Inheritance of an Acquired Small RNA-Based Antiviral Response in C. elegans, Cell, Volume 147, Issue 6, 9 December 2011, Pages 1248-1256.
- Conclusion: "We have described here a series of genetic experiments that provide support for the existence of non-Mendelian, multigenerational inheritance of extrachromosomal information. This information is transmitted in the form of small RNAs, viRNAs, which are induced by an episode of viral replication and which are propagated through the germline in a non-template-dependent manner. Our results therefore support the Lamarckian concept of the inheritance of an acquired trait." 17 Dec 2011
- see: chapter 9 'The Darwinian, Lamarckian, and Wrightean modalities of evolution, robustness, evolvability, and the creative role of noise in evolution.' in: Eugene Koonin (2011) "The Logic of Chance". 20 Dec 2011
- Eugene V Koonin and Yuri I Wolf (2009) Is evolution Darwinian or/and Lamarckian?, Biology Direct 2009, 4:42 "A discussion of the evolutionary phenomena that appears to involve Lamarckian or quasi-Lamarckian mechanisms." Wiki says: "Through the CRISPR/Cas mechanism, bacteria can acquire immunity to certain phages and thus halt further transmission of targeted phages. For this reason, some researchers have proposed that CRISPR/Cas is a Lamarckian inheritance mechanism".
- Jordi Xiol, Ramesh S. Pillai (2012) Outsourcing Genome Protection, Science 3 August 2012:
So it seems we have here a Lamarckian inheritance of immunological RNAs!
"Eukaryotic genomes are populated by invading mobile genetic elements called transposons that threaten genome stability as they may cause mutations and chromosomal rearrangements. In animal germ lines, protection against these parasitic elements is conferred by Piwi proteins and their associated ~20- to 30-nucleotide small RNA guides, called Piwi-interacting RNAs (piRNAs), which actively repress transposons to safeguard the genetic information. ... piRNAs function as an immune system that distinguishes transposons from cellular mRNAs and, once they identify a threat, mount an enhanced response. ... 22G-RNAs establish an epigenetic memory that mediates transgenerational repression".
- Stan J. J. Brouns (2012) A Swiss Army Knife of Immunity, Science, 17 Aug 2012:
Again, it looks like Lamarckian inheritance of immunity. However, if the organism is able to recognize foreign dna in the first place, what is the additional value of incorporating it in their own dna? Especially, if the information is quickly outdated?
"Bacteria and archaea defend themselves against these invasive elements using an adaptive immune system based on clustered regularly interspaced short palindromic repeats (CRISPRs). (...) The CRISPR field was set in motion 5 years ago by the discovery that lactic acid bacteria become highly resistant to virus infection when they incorporate virus DNA fragments in their array of memorized invaders. (...) Despite the seeming efficiency of this cleavage and recycling process, the Achilles' heel of Cas9 was also uncovered. Viruses escape immunity by making point mutations in either the memorized regions of their genomes".
- See wikipedia page Somatic hypermutation for an up-to-date status of the field with many recent publications of Edward Steele.