The earliest members of a phyletic series are usually small in size and undifferentiated in structure, while the later members show a progressive increase in size and complexity.
These investigations demonstrated that it was possible to follow out step by step in superjacent strata the actual evolution of fossil species and to establish the actual "phyletic series.
Variation along the phyletic lines is gradual[551] and determinate, and appears to obey definite laws.
The careful study of phyletic series brought to light the significant fact that these lines of filiation tend to run for long stretches of time parallel to, and distinct from one another, without connecting forms.
The phyletic series of the true elephants in Europe are relatively short, and go back only to the Quaternary, Elephas antiquus giving origin to the Indian elephant, E.
The pith of my biogenetic principle is expressed in these and the remaining theses on the causal nexus of biontic and phyletic development.
In any case, we cannot regard the thread formation as a general elementary structure of plasm; in my opinion, it is always a secondary phyletic product of living matter, and never a primary feature of it.
The very word "recapitulation" implies a partial and abbreviated repetition of the course of the original phyletic development, determined by the "laws of heredity and adaptation.
As Weismann has properly observed, this internal principle of evolution, which dispenses with adaptation in the true sense of the word, is at the bottom merely a "phyletic vital force.
The close correlation which it establishes between individual and phyletic development, and which depends on the interaction of heredity and adaptation, makes it possible to explain both.
But if precisely the most essential features of the organisation thus depend upon adaptation, what is left for a phyletic force to do, since it is these essential features of the structure it would have to determine?
In the second place, the older phyletic form may not be abandoned while a newer form is being developed therefrom, but the former may alternate with the latter, as we see in the case of seasonally dimorphic butterflies.
The genus Vanessa (in the wide sense) appears to be in a remarkable condition of what may be called phyletic preservation.
All explanations of the second form of incongruence from the point of view of a phyletic force can also be shown to be absurd.
At the time of writing I drew no conclusion from these facts with reference to the phyletic development of these larval forms; nor did Bütschli, six years later, in the precisely analogous case of the larvæ of the bees.
Were the Axolotl a species retarded in phyletic development, the presence of a gland which does not occur in any other Perennibranchiata, and which is only of use for life upon land, would be quite inexplicable.
Three stages in the life of the species, representing three phyletic stages of the genus.
Hence, transmutation is simply a physiological process, a phyletic growth.
Although Dikkomys is towards the beginning of this phyletic sequence and Pliosaccomys towards the end of the sequence, the primitive features shared by the two provide a generalized morphotype for the subfamily Geomyinae.
The castanops group may be survivors of the ancestral lineage that diverged in two different stages in the phyleticdevelopment of the main line.
In this case, the lineage giving rise to Pliosaccomys passed through the same phyletic stages in its evolution in the early Pliocene (and possibly the late Miocene) as did the entoptychines in the late Oligocene and early Miocene.
The paucity of early and middle Pleistocene deposits from this critical region prevents any definite statements about phyletic development within the genus.
In addition, three other trends, or specializations, in evolution characterize the phyletic development of Geomys.
Each of these trends occurred independently in the Thomomyini, and each is an example of parallelism in the phyleticevolution of the two lineages.
The U-pattern of pre-Miocene entoptychines, therefore, may have become the dominant occlusal pattern only in the later stages of phyletic development.
Examination of these modern species would not radically change the estimation of the degree of phyletic development of the genera and subgenera involved.
Actually, the Illinoian material is too fragmentary to show clearly its taxonomic or phyletic affinities with the species of the later Pleistocene.
The early phyletic development of the subfamily Geomyinae took place in the tribe Dikkomyini from the early Miocene into the early Pliocene.
Even so, a considerable amount of parallelism is evident in thephyletic trends of the two genera.
A more reasonable hypothesis is that the evolution of opposable digits took place in a phyletic line that had as its ancestral stock a frog with generalized hands and feet.
If subsequent investigations show, as seems likely, that the small specialized phyllomedusines are a natural phyletic unit, the generic name Pithecopus is available.
The distinctive combination of morphological, physiological, chromosomal, and behavioral characteristics is strongly suggestive that these frogs represent an early phyletic divergence within the Hylidae.
The Agalychnis phyletic line has one kind of specialization for an arboreal existence.
A) The heart of education as well as its phyletic root is the vernacular literature and language.
Few purer types of the rehearsal by the individual of the history of the race can probably be found even though we can not yet analyze the many elements involved and assign to each its phyletic correlate.
As we shall see later, one of the best norms here is phyletic emphasis, and what lacks this must at best be feeble; and if new powers are unfolding, their growth must be very slow and they must be nurtured as tender buds for generations.
This is due to its great variety of occupations, healthful conditions, and the incalculable phyletic reënforcement from immemorial times.
We sometimes see wide-reaching phyletic conclusions advanced by writers who we know have not specific knowledge of the groups in question.
But his enormous output of accurate description and of delineation of the most varied forms, has provided a sure basis upon which the more modern seeker after phyletic lines may proceed.
In our days of complete reconciliation, when every tyro lisps in phyletic numbers as the outcome of Darwin's work, it is not amiss to recall the struggle at its inception--lest we forget.
It is only on such a foundation that sound phyletic argument can proceed.
This is a specially illuminating passage for us at a time when anatomical characters are becoming ever more important as phyletic indices.
There is no trace of the subdorsal line shown in the figure, so that this species thus appears to be in the third phyletic stage of development.
Herein is clearly expressed the difference of this view from that other one according to which the inciting principle of modification is not in the environment, but lies in the organism itself in the form of a phyletic vital force.
The suppression of phyletic steps increases with the advancement in phyletic development.
Livornica concludes its development at this phyletic stage.
Surely only that law or force of heredity known by its effects, but obscure with respect to its causes, through which old phyletic stages sometimes suddenly reappear, or in other words, that power through which reversion takes place.
This leads to the fifth section, in which I have attempted to test certain objections to the admission of a “phyletic vital force.
Caterpillars which, when full grown, belong to the seventh phyletic stage, e.
Mere reversion forms may die off without propagating themselves; but a new form called forth by the action of a phyletic vital force should not be sterile, because this is the precise “aim” which the vital force had in view.
I maintain that this, as I have already briefly indicated above, is wholly incompatible with the admission of a phyletic force.
The five first stages | The five first stages of the development of | of the individual | of the phyletic or the animal body.
The phyletic development of the six higher animal tribes, which are all derived from the Gastraea, deviated at this point in two directions.
The communal or cenobitic soul (coenopsyche): second stage of phyletic psychogenesis.
Primary reflex actions are those which have never reached the stage of consciousness in phyletic development, and thus preserve the primitive character (by heredity from lower animal forms).
The cell-soul (or cytopsyche): first stage of phyletic psychogenesis.
The specialized vocal sac structure in Phrynohyas and Trachycephalus suggests that these two genera may be rather closely allied and represent a single phyleticline from an ancestral stock similar to Osteocephalus.
Argenteohyla is quite distinct from Phrynohyas and Trachycephalus and apparently represents a distinct phyletic line from the ancestral stock.
All the species appear to be making for the same goal, and the question thus arises whether there may not be an innate force urging their phyletic development.
General conclusion as to the elimination of a phyletic vital force, 511.
The distance from the central point (the parent-form) indicates the grade of phyletic development which the respective species have at present reached.
The phyletic stages indicated by queries are extinct, and only known through the ontogeny of existing species.
In this case there is therefore no necessity for assuming a phyletic vital force.
Should these observations receive wider confirmation, it would be fair to conclude that this species is now in two states of phyletic development, the more advanced stage being represented by the brighter spotted variety.
Results of the three foregoing essays: denial of a phyletic vital force, 634.
By utilizing the combination of many morphological and biological factors, the genus Smilisca can be defined reasonably well as a natural, phyletic assemblage of species.
The second phyletic line gave rise to the sordida group and diverged from the prototype in the development of an angular maxillary and a breeding call consisting of a primary note followed by secondary notes.
This phyletic line retained the larval characters and breeding call of the prototype.
The frogs in this phyletic line retained the moderate size of the prototype and did not develop additional dermal bone.
Thus the continuity of the germ-plasm is established at least for the beginning of the phyletic series of development.
In other words, the phyletic development would proceed hand in hand with the ontogeny corresponding to it, although not from any internal cause, but as an adaptation to the existing conditions of life.
Hence we may fairly attribute to the adult organism influences which determine the phyletic development of its descendants.
In Daphnidae the cause and object of the phyletic development of parthenogenesis may be traced more clearly than in any other group of animals.
In this case therefore the word germ may be rightly applied, and Ichthyophthirius affords an interesting example of the phyletic origin of germs among the lower Flagellata and Gregarines.
It is obvious that the phyletic development of colonies or stocks must have succeeded that of single individuals, and that the formation of germ-cells in the latter must therefore represent the original method.
The phyletic acquisition of the capability of parthenogenetic development must therefore depend upon an alteration in the capability of growth possessed by the nucleus of the egg.
Hence the child corresponds in different periods of its development to the phyletic stages in the descent of man.
But, as Weismann remarks, Naegeli's phyleticforce is conceived as a thoroughly scientific mechanical principle.
These tertiary remains, chiefly of Eocene and Miocene date, fill many gaps between existing genera of Primates, and afford us quite a clear insight into the phyletic development of this order during the millions of years of the Caenozoic age.
They are independent of all future anatomical, embryological, and palaeontological discoveries which may possibly throw more light upon the details of our phyletic anthropogenesis.
Consequently a different phyletic arrangement than that proposed by Wood (loc.
Wood (1935) presented a diagnosis of the early phyletic history up to and through Cupidinimus; this is probably as correct as can be made.
The first has been the attempt to ascribe to the constant action of the same selective force the openings from their inception in primitive members of a phyletic line to their fullest expression in terminal members.
Its primacy is reflected in the phyleticexpansion of the temporal openings to permit greater freedom of the muscles during contraction.
Perhaps Pliozapus and Eozapus represent one phyletic line and Zapus and Napaeozapus a second line, both of which lines evolved from a pre-zapidine stock in the Miocene.
The phyletic branches of the genus Zapus possibly developed from geographic segments of a population radiating from the centrally located progressive group.
Sacrifice and Compensation in the Phyletic Activities.
Sacrifice and Compensation in thePhyletic Activities 16 a.
The question next demanding our attention is--do the sacrifices which are made incident to our phyletic activities receive a compensation?
Those directed towards the maintenance of self are called egoistic activities, while those directed to the maintenance of the race are called phyletic activities.
Thus we see that the building and maintenance of orphanages, hospitals, asylums and "homes," are activities that belong clearly to the group of phyletic or altruistic activities.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "phyletic" in a variety of sentences. We hope that you will now be able to make sentences using this word. Other words: clannish; direct; family; genetic; lineal; national; phylogenetic
