CR, Adams JR, Waits LP. Pedigree-based assignment tests for reversing
coyote (Canis latrans) introgression into the wild red wolf (Canis
population. Mol Ecol. 2003 Dec;12(12):3287-301. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14629346
The Russian cytologist N.N. Vorontsov was one of the first to call attention to the independence in sex determination: i.e., "an independent occurrence of the XX-XY system in Melandrium as well as in many Insects and Mammals, whereas the ZW-ZZ system evolved independently in Trichoptera, Lepidoptera, Serpentes and Aves. Against the background of these facts it is unclear whether the male species of different groups are homologous to each other or not; they appear to be nonhomologous."
[Vorontsov, N. N., 1973 The Evolution Of The Sex Chromosomes. In: Cytotaxonomy and Vertebrate Evolution, edit. A. B. Chiarelli and E. Capanna. p. 646. Academic Press, New York.. See page 646]
"Just as the transition from isogamy to anisogamy and to oogamy took place independently of each other in the various phyla of plants so the formation of mechanisms of the cytogenetical sex determination with differentiated heterochromosomes follows the same pattern in various kingdoms and phyla and results in an independent occurrence of the XX-XY system" and "the ZW-ZZ system."
["Hairless mutants are known in Peromyscus, Mus musculus, Rattus rattus, R. norvegicus, Canis familiaris, Ovis aries. Hairlessness as norm is found in 53 among contemporaneous 1037 mammalian genera... Part of these cases (hairlessness in all Cetacea and Sirenia) may be explained in terms of... macromutations... [and also] in the bat Cheiromeles and the rodent Heterocephalus (Bathyergidae)... [and in] walrus (Odobenus)... the possibility of fixation of a macromutation in nature as a species and genus character contradicts strongly the concept of obligatory gradualism of evolution." Genetika. 1988 Jun;24(6):1081-8. Macromutation and evolution: the fixation of Goldschmidt's macromutations as species and genus traits. Hairlessness mutations in mammals. Vorontsov NN: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3049233 , "Mechanisms of the fixation of Goldschmidt's "systemic mutations" during phylogeny are discussed." Genetika. 2003 Apr;39(4):519-24. Macromutations and evolution: fixation of Goldschmidt's macromutations as species and genus characters. Papillomatosis and appearance of macrovilli in the rodent stomach. Vorontsov NN: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12760252]
In addition to the devices mentioned by Vorontsov, other independent mechanisms include, "In the social insects, the female is diploid, the male haploid, a situation that also occurs in certain rotifers. In addition to these chromosomal mechanisms, the temperature during sensitive embryonic stages can serve to determine the sex as in some turtles and crocodilians. Sex reversal is common in certain animals as well as other forms of sex determination such as the age of the eggs when fertilized. This huge and varied literature has been reviewed by Bull [Bull, J.J. (1983) Evolution of Sex Determining Mechanisms. Benjamin Cummings, Menlo Park.] This is hardly the sort of situation one would anticipate if sexual reproduction were a requirement for evolutionary change."
"Any theory of evolution must recognize and incorporate nonhomology when that becomes evident. It is to the credit of Vorontsov that he did so when describing the various sex determining systems which have evolved. They have indeed evolved independently and accordingly are by definition nonhomologous. Another example of nonhomology which correlates beautifully with the various sex determining devices which have evolved is demonstrated by the origins of the germ cells in contemporary vertebrates."
"Not only are the cytological mechanisms of sex determination often nonhomologous but the expression of the sexual phenotype may also be nonhomologous. For example, both Drosophila and all mammals have a heteromorphic (different form) XY male - XX female system. However, sexual differentiation is mediated at the local cellular level in Drosophila but by means of hormones in all mammals. It is obvious that the two systems are in no sense related but independent."
"One of the hitherto most baffling features of vertebrate ontogeny is offered by the origin of those cells (oogonia and spermatogonia) destined to become the eggs and sperm."
"All known mammals have male heterogamety with the familiar XY male and XX female. By contrast, all birds are the opposite with ZW females and ZZ males." And a similar dichotomy "within the amphibia with most urodeles (newts and salamanders) like birds and all anurans (frogs and toads) except Xenopus like mammals. In reptiles examples of both kinds occur as well as temperature determination of sex in certain turtles and crocodilians."
"Among the arthropods similar differences prevail. Diptera generally have heterogametic males while Lepidoptera are like birds and urodeles with heterogametic females. In the social insects a haplo-diplo (male-female) system operates. In certain parasitic forms even the size of the host can determine the sex of the parasite. The literature is well reviewed in Bull's (Bull 1983, see above) book significantly titled "Evolution of Sex Determining Mechanisms".
"The vertebrate gonad develops from portions of the urogenital ridge, a bipartite structure consisting of an outer cortex and inner medulla. The gonadal cortex develops into the ovary, the medulla into the testis. Oddly the vertebrate gonad is a sterile organ completely incapable of functioning as a germinal epithelium. During embryonic development the gonad receives, by a process of invasion, presumptive germ cells from extra-gonadal sources. Gonads failing to receive these cells remain sterile, while those receiving presumptive germ cells differentiate with the sex of the host organ not that of the donor cells. Thus the gonad proper is clearly a part of what Weismann called the somatoplasm."
"The important point to make here is that the sources as well as the means of induction and modes of reaching the gonad vary in nonhomologous fashion from vertebrate group to group in a manner which remarkably parallels the equally nonhomologous modes of sex determination."
"In mammals, including man, the presumptive germ cells are first seen in the region of the allantois corresponding roughly to the position of the urinary bladder in the adult. From here they migrate anteriorly and laterally to enter the embryonic gonad. In birds the future germ cells originate outside the embryonic axis in the extra-embryonic endoderm consisting of the so-called germinal crescent anterior and lateral to the head. From here they enter the vitelline circulation and after a period in the circulatory system invade the gonad after first passing through the walls of the venous circulation. Reptiles as one might expect show a similarity with variations on the bird mechanism. It is in the amphibia that the most dramatic differences are manifest in the origin of the germ cells. From their monograph Nieuwkoop and Sutasurya write (see below):
"When comparing PGC formation in the urodeles with that in the anurans, one is unavoidably led to the conclusion that not only do the PGCs originate from two different sites in the two groups, but that there are moreover two fundamentally different mechanisms at work ... In the anurans all the PGCs originate from the endodermal moiety of the egg in the vicinity of the vegetal pole, whereas in the urodeles they arise from the animal 'ectodermal' moiety, more particularly the presumptive lateral plate mesoderm in the ventral to ventro-lateral equatorial region. In the anurans all the descriptive and experimental evidence pleads in favor of the predetermined nature of the PGCs, based on the presence of a germ-cell-specific sytoplasmic component, the germinal plasm, which is present in the embryo from the very beginning of development. In constrast, in the urodeles the PGCs develop strictly epigenetically from common, totipotent cells of the animal moiety under the inductive influence of the ventral yolk endoderm" [Nieuwkoop, P.D. & Sutasurya, L.A. (1979) Primordial Germ Cells in the Chordates. Cambridge Univ. Press, Cambridge.]
["Markedly different mode of mesoderm formation in anuran and urodelan amphibians (which is related to the early double-layered nature of the anuran blastula wall in contrast to its single-layered nature in the urodeles), but particularly the fundamentally different place and mode of origin of the primordial germ cells in the two groups of amphibians." Nieuwkoop PD, Sutasurya LA. Embryological evidence for a possible polyphyletic origin of the recent amphibians. J Embryol Exp Morphol. 1976 Feb;35(1):159-67: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=1083885]
"Note the clear correlations between nonhomologous modes of sex determination and equally nonhomologous methods and sources for germ cell formation. As I have indicated elsewhere any theory of evolution must include in its postulates these fundamental differences (Davison 1984, see above). As well as I can determine the neo-Lamarckians, the neo-Darwinians, and the Creationists all fail even to acknowledge the existence of this experimental and descriptive literature, not to mention its significance for their particular views. In that respect the Creationists are missing an opportunity for their case since nonhomology means separate origin, which prima facie might be interpreted to mean special creation."
"First, since the definitive sex cells of the various vertebrate groups cannot be homologized, they cannot be considered as ancestral cell lineages. Rather they are secondary or derived lineages correlated in their origins with the equally independent and nonhomologous invention of sexual reproduction."
"The actual facts are as follows. In birds the cells destined to become the germ cells first appear in the extra-embryonic endoderm (germinal crescent) anterior to the head of the developing embryo. Incidentally, this region has no homologue in the hatched bird as the extra-embryonic endoderm is, by definition, resorbed as nutrient for the developing chick. From there the presumptive germ cells enter the circulatory system and, after a period of time in the bloodstream, penetrate the walls of the venous circulation and invade the gonad where they differentiate into the definitive gametes. In mammals the presumptive germ cells first appear in the endoderm of the allantois, a structure destined to become the urinary bladder of the adult. From here they migrate in amoeboid fashion anteriorly and laterally to reach the gonad where they complete their differentiation. Thus, there is no way that the reproductive cells of mammals can be homologized with those of birds as they originate from opposite ends of the embryonic axis and reach the gonads by completely different means."
[See also: "To maintain a forebrain or even a neural phenotype, cells must receive stabilizing signals (`stabilization step'). This maintenance function might be provided by prechordal plate mesendoderm and/or anterior head process, both of which emerge from the organizer region during gastrulation... By stage 4- the hypoblast expression is displaced further anteriorly into the forming germinal crescent, which extends bilaterally and caudally... We propose that retinoids have a dual role in patterning the anterior forebrain during development. During early gastrulation, retinoic acid (RA) acts in anterior endodermal cells to modulate the anteroposterior (AP) positional identity of prechordal mesendodermal inductive signals to the overlying neuroectoderm. Later on, at neural pore closure, RA is required for patterning of the mesenchyme of the frontonasal process and the forebrain by modulating signalling molecules involved in craniofacial morphogenesis. RA signalling is involved in patterning anterior endodermal cells. It is well established that the primitive (or extra-embryonic) and definitive (or embryonic) endoderm are required for forebrain development; however, little is known about the molecular mechanisms and signalling pathways involved in this process." Development 130, 2039-2050 (2003) A novel role for retinoids in patterning the avian forebrain during presomite stages. Aida Halilagic, Maija H. Zile and Michèle Studer: http://dev.biologists.org/cgi/content/full/130/10/2039]
"Similarly, the eggs and sperm of the Anura (frogs and toads) arise in an entirely different way than do those of the Urodela (salamanders and newts). Staining methods reveal that in frogs, the cells destined to become the germ cells result from the presence of preformed granules near the vegetal pole of the unfertilized egg, a region destined to become part of the endoderm. From there they move first dorsally and then laterally to enter the embryonic gonads which are mesodermal structures. In salamanders the presumptive germ cells first appear in the mesoderm as a result of the inductive action of the underlying endoderm on the lateral plate mesoderm. From there they migrate medially to invade the embryonic gonads. Thus the germ cells of the Anura and the Urodela do not even arise from the same germ layer! In short, there is not a scintilla of evidence to support the notion of germ cell continuity. The details of these differences have been discussed elsewhere (Davison 1984). Also, the vertebrate gonad is a sterile organ unable to produce germ cells from its own epithelium (Nieuwkoop and Sutasurya 1979). Instead, the testis or ovary receives its complement of eggs or sperm by a process of invasion from extragonadal sources early in development. Since the sources and modes of invasion are not homologous from group to group, the continuity of the germ plasm is a myth."
[My comment (http://www.geocities.com/fdocc3/christ.htm): "There is Continuity in the female ovules within the same true species, but not in the male sperms. Specifically there is Continuity in the human female ovules." See for example: "we should seriously look for the mechanism whereby mortality as an acquired character has been transmitted. There is no particular reason to assume that such a mechanism exists among other living things; indeed, we know that for millions of living things, such a mechanism does not exist, for they are truly potentially immortal." "The seed of the woman is the only remnant that has retained the original immortality possessed by our first parents." "Generation after generation, the seed of the woman reiterates itself." A. C. Custance, The Seed of the Woman, 1980, Doorway Publications, Ontario, pp. 210-232, 254-267, Online at custance.org; see also: "The ovum, considered as a living organism (which indeed it is), need never experience death, provided that it is induced to divide and multiply by successive divisions," "the single ovum becomes another ovum one generation later in history and no corpse is left behind as evidence of its death," "the two "daughter" cells in turn divide, if fertilized, and so, the line goes on unbroken and can continue endlessly," "fertilization of the ovum is really only a means for preserving its integrity, until one generation later, it is again released and presented for fertilization. And so it is simply passed on and on, generation after generation, in an unbroken chain of continuous life. The living ovum is the ovum of yesterday" (Custance on reading: Weismann, August, Essays Upon Heredity and Kindred Biological Problems, tr. E. B. Poulton, S. Schonland and A. E. Shipley, Oxford, 1889, 1892, in 2 vols., Vol. 1, p. 26.)."]
"As someone so aptly put it: "Hypotheses have to be reasonable -- facts don't" (Anonymous.)"
"Note that these nonhomologies correlate favorably with the nonhomologous devices that serve to determine the sex differences. In order to deal with all this, it is necessary to postulate that contemporary reproductive cell lineages cannot be ancestral"
["The theory of programmed death [was initially] suggested by August Weismann." ScientificWorldJournal. 2002 Feb 7;2:339-56. Evolutionary theories of aging and longevity. Gavrilov LA, Gavrilova NS:http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12806021, "For various reasons, Weismann's ideas on ageing fell into neglect following his death in 1914, and cytogerontology has only reappeared as a major research area following the demonstration by Hayflick and Moorhead in the early 1960s that diploid human fibroblasts are restricted to a finite number of divisions in vitro. In this review we give a detailed account of Weismann's theory, and we reveal that his ideas were both more extensive in their scope and more pertinent to current research than is generally recognised." Hum Genet. 1982;60(2):101-21. Cytogerontology since 1881: a reappraisal of August Weismann and a review of modern progress. Kirkwood TB, Cremer T: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7042533, "August Weismann is famous for having argued against the inheritance of acquired characters. However, an analysis of his work indicates that Weismann always held that changes in external conditions, acting during development, were the necessary causes of variation in the hereditary material. For much of his career he held that acquired germ-plasm variation was inherited. An irony, which is in tension with much of the standard twentieth-century history of biology, thus exists - Weismann was not a Weismannian." J Hist Biol. 2001 Winter;34(3):517-55. August Weismann on germ-plasm variation. Winther RG: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11859887, "August Weismann popularized the notion that metazoans have a potentially immortal germ line separated from a mortal soma" Proc Natl Acad Sci U S A. 1992 Oct 15;89(20):9920-3. Asexual metazoans undergo senescence. Martinez DE, Levinton JS: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11607334, "None of these patterns contradict Weismann's hypothesis, but they do show that many additional principles unrelated to the function of sex are required to fully explain its distribution. Weismann's hypothesis is also consistent with what we know about the mechanics and molecular genetics of recombination, in particular the tendency for chromatids to recombine with a homolog rather than a sister chromatid at meiosis, which is opposite to what they do during mitosis." : Evolution Int J Org Evolution. 2000 Apr;54(2):337-51. Perspective: sex, recombination, and the efficacy of selection--was Weismann right? Burt A: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10937212,"A. Weismann's theory of germ plasm is of special importance... predicted reduction division, the continuing of germ plasm and the significance of chromosomes in heredity. For the first time it brought a new methodology to the experimental genetics and the idea of interdisciplinary synthesis." Muzrukova EB. A. Weismann's germ-plasma theory: a new methodological approach to the problems of general biology. Zh Obshch Biol. 1997 Nov-Dec;58(6):99-107:http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9494429]
Repeating the simple facts again: "There is no way that the reproductive cells of mammals can be homologized with those of birds. Similarly, the eggs and sperm of frogs arise in an entirely different way than do those of salamanders and accordingly cannot be assumed to exhibit homology. In short, there is not a scintilla of evidence to support the notion of the continuity of the germ plasm" [between the different real species.]
These nonhomologies correlate beautifully with the equally nonhomologous devices that determine the sexes. "This remarkable conclusion is of course totally incompatible with the neo-Darwinian concept of the evolutionary process."
Understanding the nature of sexual reproduction and the manner in which eggs
and sperm are produced:
"In all diploid animals and plants the chromosomes occur in pairs. One member
of each pair comes from one parent, the other from the other parent. Thus, each
egg or sperm must have only one of each kind of chromosome, a condition known as
haploidy. The process by which this reduction takes place is known as meiosis or
chromosome reduction... If one were to imagine the simplest way that chromosome
reduction could take place it might be as follows. The chromosomes would align
in pairs and a single division would take the chromosome number from diploid to
haploid. Not a single living creature undergoes meiosis in this way. Instead,
each chromosome is duplicated taking the chromosome number from diploid to
tetraploid. Then while they are in alignment (synapsis) a very important step
occurs. Breaks occur in some of the chromosomes and exchanges occur between the
original pairs of chromosomes a phenomenon known as crossing over. Following
this event, the chromosomes undergo the first meiotic division returning the
chromosome number from tetraploid to diploid... The two originally identical
chromosomes (known as sister strands) always remain together. Note that this
first meiotic division is a perfectly valid form of diploid reproduction...
meiosis involves two steps."
EB. A. Weismann's germ-plasma theory: a new methodological approach
to the problems of general biology. Zh Obshch Biol. 1997
PD, Sutasurya LA. Embryological evidence for a possible
polyphyletic origin of the recent amphibians. J Embryol Exp Morphol.
P.D. & Sutasurya, L.A. (1979) Primordial Germ Cells in the
Chordates. Cambridge Univ. Press, Cambridge.
M, Matsumura M. Retinal degeneration of the celestial goldfish
(author's transl). Nippon Ganka Gakkai Zasshi. 1980;84(5):350-3.
William Bateson's introduction of Mendelism to England: a
reassessment. Br J Hist Sci. 1987 Oct;20(67):399-420.
K. Knowledge held in common. Tales of Luther Burbank and science in
the American vernacular. Isis. 2001 Sep;92(3):484-516. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11810893
N. Theory and practice: the impact of Mendelism on agriculture. C
R Acad Sci III. 2000 Dec;323(12):1107-16: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11147097
Yoshiyuki and the International Chimpanzee Chromosome 22 Consortium,
"DNA sequence and comparative analysis of chimpanzee chromosome 22,"
429:382-388, May 27, 2004. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15164055
H, Negi A, Matsumura M, Ohkuma M, Honda Y. The developmental changes
of ERGs on spontaneous retinal degeneration of Celestial goldfish. Doc
Ophthalmol. 1988 Sep;70(1):97-101. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3229298
RL, Weerheim JA, Sivak JG. Role of the lens and vitreous humor in the
refractive properties of the eyes of three strains of goldfish. Vision
N. N., 1973 The Evolution Of The Sex Chromosomes. In: Cytotaxonomy
and Vertebrate Evolution, edit. A. B. Chiarelli and E. Capanna. p. 646.
Press, New York. (See page 646.)
NN. Macromutation and evolution: the fixation of Goldschmidt's
macromutations as species and genus traits. Hairlessness mutations in
Genetika. 1988 Jun;24(6):1081-8. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3049233
NN. Macromutations and evolution: fixation of Goldschmidt's
macromutations as species and genus characters. Papillomatosis and
macrovilli in the rodent stomach. Genetika. 2003 Apr;39(4):519-24. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12760252
August, Essays Upon Heredity and Kindred Biological
Problems, tr. E. B. Poulton, S. Schonland and A. E. Shipley, Oxford,
1892, in 2 vols., Vol. 1, p. 26.
M.J.D. (1973) Animal Cytology and Evolution. Comstock Publ. Co.,
Ithaca, New York
RG. August Weismann on germ-plasm variation. J Hist Biol. 2001
JJ, Prakash O. The origin of man: a chromosomal pictorial legacy.
Science. 1982 Mar 19;215(4539):1525-30. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7063861
This is what I have read in my beloved Bible related
1Co 15:39 All flesh is not the same
but one kind of flesh of men,
and another flesh of beasts, and another of fish,
and another of birds.
The sharp difference is emphasized between feathers, scales,
fur, and skin.
1Co 15:40There are also heavenly
bodies and earthly bodies. But the glory of the heavenly is truly different,
that of the earthly different
Then, this is what William Bateson declared related to
"I do not dare to suggest that in magnitude or splendour the
field of Genetics may be compared with that now being disclosed to the
or the astronomer; for the glory of the celestial is one and the glory
terrestrial is another."