homologous-structures

HURDLE NUMBER 58. THE HOMOLOGOUS STRUCTURES HURDLE.

Imagine the following (purely hypothetical) scenario:- A lizard “evolves” into a newt, so as to “take advantage” of an aqueous environment. An investigation of the genes and embryology of lizards and newts is undertaken. In the lizard, there are specific genes that control production of the forelimbs. Also the forelimbs form in one particular segment of the lizard embryo. Now, to the consternation of the investigators, it is discovered that the forelimbs of the newt are formed IN AN ENTIRELY DIFFERENT SEGMENT of the (newt) embryo, and also are controlled by genes that are IN A COMPLETELY DIFFERENT PORTION OF THE CHROMOSOMES. This is a serious blow to the notion that newts evolved from lizards. If the embryonic segments and positions of the controlling genes were the same for both lizard and newt forelimbs, this would be ok. This would support the notion that newts had evolved from lizards. If the embryonic segments and positions of the controlling genes were COMPLETELY DIFFERENT for lizard and newt forelimbs, then this would seriously undermine the notion that newts evolved from lizards by a series of small random mutations.

What we are seeing here is a single huge quantum leap from one specific configuration of the DNA software of the lizard to a completely different, totally reorganized configuration of the DNA software of the newt (nevertheless producing a fairly similar morphological format). (The same comment applies to the entirely different “embryological agendas” of lizard and newt)

It turns out that the above hypothetical scenario (employed for illustration purposes only) is actually NOT so hypothetical after all. With this in mind, check out the following quotes:-

The following quotes are from the book Icons of Evolution, by Jonathan Wells (who studied at the University of California, Berkeley, where he earned a PhD in molecular and cellular biology in 1994. He became a member of several scientific associations and has published in academic journals.), published by Regnery Publishing Inc., 2000:-

Page 62:- “Biologists have known for decades that homologous features are not due to similar genes.” (Note:- I should explain the term “homologous”. A mammalian forelimb is homologous with a bird’s wing – because one supposedly “evolved” from the other. To describe two features as “homologous” implies that one of those features supposedly “evolved” from the other feature.)

Pages 71 to 72:- The author quotes developmental biologist Pere Alberch (He obtained a PhD in Zoology at the University of California. Between 1980 and 1989 he worked as both a biology professor at Harvard University and as a curator of herpetology at the Museum of Comparative Zoology. He worked as an editor for magazines such as Trends in Ecology and Evolution (since 1993), Biodiversity Letters (since 1992), Journal of Theoretical Biology (since 1985) and Journal of Evolutionary Biology.):- “Homologous structures form from distinctly dissimilar initial states.”

Page 71:- The author quotes Gavin de Beer (In 1945, de Beer became professor of zoology and was, from 1946 to 1949, president of the Linnean Society. Then he was director of the British Museum (Natural History) (now the Natural History Museum), from 1950 until his retirement in 1960.):- “Correspondence between homologous structures (ie:- in different species) cannot be pressed back to similarity of position of cells in the embryo.”

Page 73:- Wells tells us that “ Homologous structures need not be controlled by homologous genes.” Then Wells provides a further quote from Gavin de Beer:- “The inheritance of homologous structures from a common ancestor cannot be ascribed to identity of genes.”

Page 76:- Gavin de Beer is again quoted:- “What mechanism can it be that results in the production of homologous organs, the same “patterns”, in spite of their NOT being controlled by the same genes?” (My capitals.)

The next quote is from the book The Living Stream, by Alastair Hardy (Emeritus Professor of Zoology at Oxford University), published by Collins, 1965, pages 212 to 213:-

“Homologous structures are often produced by the action of QUITE DIFFERENT GENES. - - - Identical characters may be BROUGHT ABOUT BY QUITE DIFFERENT ASSORTMENTS OF GENES. The concept of HOMOLOGY IN TERMS OF SIMILAR GENES HANDED ON FROM A COMMON ANCESTOR HAS BROKEN DOWN.” (My capitals and highlighting.)

The next quote is from the book Why Us? How Science Rediscovered The Mystery of Ourselves, by James Le Fanu (Medical Doctor, who has published in The British Medical Journal, and The Lancet), published by Harper Press, 2009, page 123:-

“The distinguished embryologist Sir Gavin de Beer (In 1945, de Beer became professor of zoology and was, from 1946 to 1949, president of the Linnean Society. Then he was director of the British Museum (Natural History) (now the Natural History Museum), from 1950 until his retirement in 1960.) - - - found that the embryological origins of these homologous limbs arose from quite different “segments” of the trunk in the newt, lizard, and man.” Le Fanu then comments:- The Common architectural plan of the forelimbs of reptiles and mammals - - - CAN NO LONGER BE INTERPRETED IN FAVOR OF DESCENT FROM A COMMON ANCESTOR.”

My comment:- Let me try to clarify this still further to show just how major this problem is for Darwinism. Consider again our original hypothetical scenario of a lizard “evolving” into a newt by successive SMALL random mutations. We start off with a lizard. Then a SMALL “favorable” random mutation occurs, making the lizard very slightly more “newt-like”. Then another SMALL favorable random mutation, the lizard again becoming just a tad more “newt-like”. Then another SMALL mutation. Then another. Then another etc etc - - - . This is how “evolution” is supposed to work. SMALL STEPS! There is no place in this scenario for a sudden change in the “embryological agenda”, whereby forelimb formation SUDDENLY MIGRATES TO SOME ENTIRELY DIFFERENT BODY SEGMENT. There is no place in this scenario for a sudden TOTALLY RADICAL RECONFIGURATION OF THE DNA SOFTWARE, so that genes on some completely different chromosome suddenly “take over” control of forelimb development. Evolution is supposed to happen in TINY TINY STEPS! There is no place in Darwinism for SUDDEN RADICAL REALIGNMENTS.

The notion that evolution can proceed by SMALL random mutations has absolutely zero merit. The Homologous Structures Hurdle simply adds more nails to the coffin of the random mutations hypothesis. (RIP!)