EVOLUTION PROTOSTOME-DEUTEROSTOME LINK

EVOLUTION – ANNELID THEORY BIBLIOGRAPHY a supplement to earlier post today.  

I will not feel bad if you don’t read this, even if you are a biologist.  If you have a specific interest in annelid theory of chordate origin, the references may be helpful.

The references below are some that I found useful in understanding the evolution of the animal phyla, especially as pertains to the annelid theory.  They tend to focus on molecular aspects if I thought they shed light on the problem.  The bibliography is a partial one and could have been greatly expanded if for example, I included all those that did not make a link to both protostomes and deuterostomes [Akam, Michael, 1998, Biol. Bull., 195:373-374 deals with shifts in Hox gene expression in segments during evolution of arthropods] or my database was defective [a 1978 invertebrate collagens article in Science, 202:591-598 has an obvious defect in the author’s name(s)].  Since disappointment with the defects [noted in my 5/31/13 post] of some phylogenetic studies over a decade ago, I have not been very attentive to subsequent reports.

Arendt, D., and K. Nübler-Jung.  1994.  Inversion of dorsoventral axis?  Nature, 371:26. 

Arendt, Detlev, Ulrich Technau, and Joachim Wittbrodt.  2001.  Evolution of the bilaterian larval foregut.  Nature, 409:81-85.

De Robertis, E. M., and Yoshiki Sasai.  1996.  A common plan for dorsoventral patterning in Bilateria.  Nature, 380:37-40.

Eakin, Richard M. 1979.  Evolutionary significance of photoreceptors: in retrospect.  Am. Zool., 19:647-653.    Fig. 1 shows great similarity of photoreceptors of annelids and cephalochordates although he puts them near the tips of separate lines

Field, Katharine G., Gary J. Olsen, David J. Lane, Stephen J. Giovannoni, Michael T. Ghiselin, Elizabeth C. Raff, Norman R. Pace, and Rudolf A. Raff.  1988.  Molecular phylogeny of the animal kingdom.  Science, 239:748-753.  “Coelomates are thus monophyletic, and they radiated rapidly into four groups: chordates, echinoderms, arthropods, and eucoelomate protostomes.”

Gardiner, Stephen L., and Meredith L. Jones.  1985.  Ultrastructure of spermiogenesis in the vestimentiferans tube worm Riftia pachyptila (Pogonophora: Obturata).  Trans. Am. Microsc. Soc., 104(1):19-44.

Gould, James L.  1985.  How bees remember flower shapes.  Science, 227:1492-1494.  “presumptive vertebrate-invertebrate dichotomy is false”  bees use search and memory process similar to vertebrates.

Lull, Richard Swann.  1945.  Organic Evolution.  Macmillan, New York.  744pp. [Revised edition, 1929, earlier 1917] a paleontologist at Yale.  Fig. 123, page 429 after Wilder of annelid theory of vertebrate origin

Meurling, Patrick.  1967.  The vascularization of the pituitary in elasmobranchs.  Sarsia, 28:1-104. 

Miyamoto, Michael M., Jerry L. Slightom, and Morris Goodman.  1987.  Phylogenetic relations of humans and African apes from DNA sequences in the ψη-globin region.  Science, 238:369-373.  “. . the slowdown in the rate of sequence evolution evident in higher primates is especially pronounced in humans.” 

Moore, Richard C., and Michael D. Purugganan.  2003.  The early stages of duplicate gene evolution.  Proc. Natl. Acad. Sci. USA, 100:15682-15687.  “Gene duplications are one of the primary driving forces in the evolution of genomes and genetic systems.”

Pellettieri, Jason, and Geraldine Seydoux.  2002.  Anterior-posterior polarity in C. elegans and Drosophia-PARallels and differences.  Science, 298:1946-1950. “par” genes important in polarization for C. elegans embryo; homologs were discovered in mammals, this study looks at fruit fly

Peterson, Kevin J., Steven Q. Irvine, R. Andrew Cameron, and Eric H. Davidson.  2000.  Quantitative assessment of Hox complex expression in the indirect development of the polychaete annelid Chaetopterus sp.  Proc. Natl. Acad. Sci. USA, 97:4487-4492.  they found a similar Hox complex utilization in cells for adult body plan in the polychaete to that process described in the sea urchin

Ritzmann, Roy E., Martha L. Tobias, and Charles R. Fourtner.  1980.  Flight activity initiated via giant interneurons of the cockroach: evidence for bifunctional trigger interneurons.  Science, 210:443-445.  “command or trigger interneurons have been identified . . . .  including annelids, arthropod, mollusks, and turtle (1).” 

Romer, Alfred Sherwood.  1962.  The Vertebrate Body, 3^rd edition.  Saunders, Philadelphia.  627 pp.    Illustration of annelid theory of chordate origin is on page 25 (same as Lull one but different caption) see pages 298-299 for transition in position of structures leading to pituitary – p. 298

Ruppert, Edward E., and Elizabeth J. Balser.  1986.  Nephridia in the larvae of hemichordates and echinoderms.  Biol. Bull., 171:188-196. 

Sarnat, Harvey B.  1984.  Muscle histochemistry of the planarian Dugesia tigrina (Turbellaria: Tricladida): implications in the evolution of muscle.  Trans. Am. Microsc. Soc., 103(3):284-294. 

Schwenk, Kurt, and Günter P. Wagner.  2001.  Function and the evolution of phenotypic stability: connecting  pattern to process.  Amer. Zool., 41:552-563. 

Smith, Peter R., Edward E. Ruppert, and Stephen L. Gardiner.  1987.  A deuterostome-like nephridium in the mitraria larva of Owenia fusiformis (Polychaeta, Annelida).  Biol. Bull., 172:315-323.

Southward, Alan J., and Eve C. Southward.  1982.  The role of dissolved organic matter in the nutrition of deep-sea benthos.  Amer. Zool., 22:647-658.  

Stein, Elizabeth A., and Edwin L. Cooper.  1983.  Inflammatory responses in annelids.  Am. Zool., 23:145-156.  inflammation of vertebrates and annelids shows related factors – histamine, agglutinins, lysins, etc.  also have amoeboid phagocytic cells   

Stoichet, Sarah A., Talat H. Malik, Joel H. Rothman, and Ramesh A. Shivdasani.  2000.  Action of the Caenorhabditis elegans GATA factor END-1 in Xenopus suggests that similar mechanisms initiate endoderm development in ecdysozoa and vertebrates.  Proc. Nat. Acad. Sci., USA, 97:4076-4081.

Terwilliger, R. C., and N. B. Terwilliger.  1987.  Are pogonophoran and annelid extracellular hemoglobin structures similar to one another?  Am. Zoologist, 27(4):32A, abstract #152.  Yes for Vestimentifera which also have a smaller Hb similar to one found in Perivata 

Tiplady, Brian, and Morris Goodman.  1977.  Primitive haemoglobin.  J. Mol. Evol., 9:343-347.  “The variations in nucleotide substitution rates were interpreted in terms of Darwinian selection, the emergence of a new function being followed by a rapid rate of evolution, which then slows down once the molecule has been optimized.” 

Tomarov, Stanislav I., Patrick Callaerts, Lidia Kos, Rina Zinovieva, Georg Halder, Walter Gehring, and Joram Piatigorsky.  1997.  Squid Pax-6 and eye development.  Proc. Natl. Acad. Sci. USA, 94:2421-2426. (March 1997)  “Pax-6 in vertebrates and its homolog eyeless in Drosophila are known to be essential for eye development.”

Wagner, Gunte P., Chris Amemiya, and Frank Ruddle.  2003.  Hox cluster duplications and the opportunity for evolutionary novelties.  Proc. Natl. Acad. Sci. USA, 100:14603-14606.  “Hox genes play a key role in animal body plan development.  These genes tend to occur in tightly linked clusters in the genome.  Vertebrates and invertebrates differ in their Hox cluster number, with vertebrates having multiple clusters and invertebrates usually having only one.”

Joseph G. Engemann    June 30, 2013

ANIMAL KINGDOM EVOLUTION

THE MAJOR GROUPS

The roots of the animal kingdom and other kingdoms are closely intertwined prior to the origin of multi-cellular plants and animals.  We think the earliest organisms are still represented today by the bacteria and other forms lacking a nucleus in their membrane-enclosed selves.  During this stage, perhaps the first billion years of evolution, the basic biochemistry of life evolved.  The RNA, DNA, and much of the basic materials still found in subsequent organisms evolved.

A consequence of the development of photosynthetic organisms in the world, then lacking oxygen in the atmosphere, was the production of oxygen as a toxic waste product that accumulated and changed the biosphere for the remaining time on earth.  Some of the early organisms developed the ability to utilize oxygen to oxidize organic material for their energy.  They could then remain active in the absence of light while extracting more energy from food than was possible by anaerobic process alone.  

Organisms that protected their genetic material from the oxygen with a nuclear membrane could better survive as oxygen reached higher levels.  Some developed a symbiotic relationship with other organisms.  Details of these early steps are discussed by Lynn Margulis (1981, Symbiosis in Cell Evolution, W. H. Freeman and Co., New York).  The evidence that mitochondria of our cells are a result of symbiosis is very strong; perhaps cilia are derived from flagella that also came from a similar symbiotic origin.

At this stage of evolution the Animal Kingdom or its one-celled progenitors, the Protozoa, had representatives so overlapping with plants and fungi that many biologists prefer to put them in a separate kingdom, the Protista.  These early steps were developing during the second billion years of life on earth.

By the beginning of the third billion years on earth a protozoan that could change back and forth from one with a flagellum to one with pseudopodia had evolved.  Sometime the pseudopodia would develop into a collar around the flagellum.  Eventually some of these dual potential cells stuck together and developed small colonies that eventually specialized into sponges.  The single cell with the capacity for diverse structure and a mechanism for controlling it needed a few control changes in a few different cells of the colony to provide the basic material for evolution of many of the features of all animals.

The Porifera were the first phylum of animals to develop.  They diversified into many different sponge types until one group gave rise to coral-like animals as indicated by the similarity to a Middle Devonian anthozoan (Kazmierczak, Jozef. 1984.  Favositid tabulates: evidence for poriferan affinity.  Science, 225:835-837.).  

Recognition of this evidence of anthozoans as the first cnidarians provides a basis for a simple continuity of phyla in the early stem of animals leading to the next phylum, the Platyhelminthes which may be considered the earliest protostomes.  A simple but unconventional view is that anthozoan polyps gave rise to jellyfish ancestral to triclad planarians.  The complexity of the simple process is why I needed to write my manuscript, Evolution Insights, to make it evident.

The sponges have less well-defined tissues than phyla that follow.   But the main mass of sponge is jelly-like with a few amoeboid cells and a tangle of collagen-like fibers and is much like loose connective tissue in our own bodies.  The jelly-like mass is mostly covered with flattened cells and is perforated by many pores leading to canals and or cavities lined with choanocytes.  Choanocytes are cells with a flagellum surrounded at the base with a collar that collects microscopic food items to nourish the sponge.  Water is passed out one or a few large openings.  Most sponges have spicules.  Spicules are mineralized (calcareous and/or siliceous), often needle-like, or three-pointed and other shapes often specific to the class of the sponge.

The protostomes included all the animals above the cnidarians until the deuterostomes evolved.  The seemingly hidden origin of deuterostomes becomes simple and clear when the role of the Pogonophora is known.  The next several blogs are expected to deal with the origin of the deuterostomes.  Then it will be time to clarify the Porifera-Cnidaria-Platyhelminthes links.  Later, the origin of mollusks and arthropods from annelids will be covered.  The foggiest portion of animal evolution, Platyhelminthes to Annelida, is obscure because the intermediate steps left neither a fossil nor living close relative to my knowledge. 

The annelids seem to be the living representatives of the most ancient animals with a true coelom, a body cavity with body wall lined with a cellular layer of flattened cells.  Organs enclosed in the coelom are also covered with a similar cellular layer; the two layers often connect to form a double layered mesentery.  The mesenteries may help keep organs in position, including blood vessels and nerves servicing them.  Of the simple animals, more complex than flatworms, but still lacking both a true coelom and segmentation (or its derivative, metamerism), although having characteristics more in common with advanced animals, we find only the nemerteans.

The protostomes including flatworms, nemerteans, annelids, mollusks, and arthropods get their name from the embryonic origin of the mouth from the blastopore.  The first (proto-) opening becomes the mouth (-stome), thus their name Protostomia.  In deuterostomes a second embryonic opening or region becomes the mouth.  The deuterostomes include hemichordates, chordates, and echinoderms.

Besides mouth origin, major contrasts between major phyla of the two groups (advanced protostomes and deuterostomes) include spiral versus radial cleavage, determinate versus indeterminate cleavage, presence or absence of chitin.  A minor phylum, the Pogonophora, blurs these and other distinctions and gives good reason to be the link between the two branches of higher animals.  To me, the evidence is so good any other proposals lack standing.  

An earlier post (SCIENCE SCREW-UP NO. 1) provides reasons the currently popular view of phylum relationships is incorrect.  Most of my immediately following posts will address various aspects of the origin of deuterostomes.  

Joseph G. Engemann, Emeritus Professor of Biology, WMU, Kalamazoo.  6/20/2013