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1.
In the evolution of anatomically modern man and his subspecies most specialists have concentrated on investigating geographical areas other than Africa as the possible area of origin.In this study 20 fossil hominids and associated faunal remains from South and East Africa were dated by microanalysis, radiocarbon, and amino-acid dating in order to see whether modern man appears later, was sympatric, or even predated Neandertal man.These dates indicate that anatomically modern man occurs sympatrically and possibly even predates the Rhodesian group of Neandertals in Africa. Modern man might also be contemporary to and possibly even predate the occurrence of Neandertal in Europe.This would indicate that modern man did not evolve from but possibly gave rise to the Neandertals as off-shoots.Two possibilities for the evolution of modern man are suggested. First, that Homo sapiens capensis evolved about 90,000 to 100,000 years ago from possibly Homo erectus by way of a “basic” Homo sapiens and later gave rise to Homo sapiens rhodesiensis, Homo sapiens afer, and possibly Homo sapiens palestinus around 50,000 years ago with Homo neanderthalensis and Homo sapiens capensis evolving separately from Homo erectus. In this case Homo neanderthalensis would be a different species from Homo sapiens which includes Homo sapiens capensis, Homo sapiens rhodesiensis, Homo sapiens afer, and possibly Homo sapiens palestinus.Secondly, Homo sapiens capensis evolved by way of a “basic” Homo sapiens with Homo sapiens rhodesiensis and Homo sapiens palestinus branching off from Homo sapiens capensis around 50,000 years ago. Before that, around 90,000 to 100,000 years ago Homo sapiens capensis evolved first and was then followed by Homo sapiens neanderthalensis from a “basic” Homo sapiens stock, but diverged. This means, all Neandertals, Homo sapiens capensis, Homo sapiens sapiens and Homo sapiens afer can be considered as subspecies of Homo sapiens.The author favors the first scheme since on relative dating grounds the existence of Neandertal man in Europe before the earliest date of Homo sapiens capensis and a “basic” Homo sapiens seems to be fairly well documented. Irrespective of either one of these possibilities, modern man evolved in Africa and seems to have migrated into Europe and other parts of the world.New absolute dating techniques are mentioned in detail like the new radiocarbon-collagen method and amino acid dating.  相似文献   

2.
Vygotsky’s The Historical Significance of the Crisis in Psychology (1926–1927) is an important text in the history and philosophy of psychology that has only become available to scholars in 1982 in Russian, and in 1997 in English. The goal of this paper is to introduce Vygotsky’s conception of psychology to a wider audience.I argue that Vygotsky’s argument about the “crisis” in psychology and its resolution can be fully understood only in the context of his social and political thinking. Vygotsky shared the enthusiasm, widespread among Russian leftist intelligentsia in the 1920s, that Soviet society had launched an unprecedented social experiment: The socialist revolution opened the way for establishing social conditions that would let the individual flourish. For Vygotsky, this meant that “a new man” of the future would become “the first and only species in biology that would create itself.” He envisioned psychology as a science that would serve this humanist teleology.I propose that The Crisis is relevant today insofar as it helps us define a fundamental problem: How can we systematically account for the development of knowledge in psychology? I evaluate how Vygotsky addresses this problem as a historian of the crisis.  相似文献   

3.
Arguments against essentialism in biology rely strongly on a claim that modern biology abandoned Aristotle’s notion of a species as a class of necessary and sufficient properties. However, neither his theory of essentialism, nor his logical definition of species and genus (eidos and genos) play much of a role in biological research and taxonomy, including his own. The objections to natural kinds thinking by early twentieth century biologists wrestling with the new genetics overlooked the fact that species have typical developmental cycles and most have a large shared genetic component. These are the “what-it-is-to-be” members of that species. An intrinsic biological essentialism does not commit us to Aristotelian notions, nor even modern notions, of essence. There is a long-standing definition of “species” and its precursor notions that goes back to the Greeks, and which Darwin and pretty well all biologists since him share, that I call the Generative Conception of Species. It relies on there being a shared generative power that makes progeny resemble parents. The “what-it-is-to-be” a member of that species is that developmental type, mistakes in development notwithstanding. Moreover, such “essences” have always been understood to include deviations from the type. Finally, I shall examine some implications of the collapse of the narrative about essences in biology.  相似文献   

4.
Prasanna K. Mohanty, a great scientist, a great teacher and above all a great human being, left us more than a year ago (on March 9, 2013). He was a pioneer in the field of photosynthesis research; his contributions are many and wide-ranging. In the words of Jack Myers, he would be a “photosynthetiker” par excellence. He remained deeply engaged with research almost to the end of his life; we believe that generations of researchers still to come will benefit from his thorough and enormous work. We present here his life and some of his contributions to the field of Photosynthesis Research. The response to this tribute was overwhelming and we have included most of the tributes, which we received from all over the world. Prasanna Mohanty was a pioneer in the field of “Light Regulation of Photosynthesis”, a loving and dedicated teacher—unpretentious, idealistic, and an honest human being.  相似文献   

5.
Abstract

New Zealand’s peculiar biota has fueled more than a century of biogeographic interest. During this time a number of workers have offered classifications synthesising biotic and geographical relationships. More recently, Fleming (1963, 1979) has recognised that these systems have much in common and tried to reconcile them into a more general scheme. He distinguished seven elements emphasising relationships with Australia and the southern ocean with less important “Holarctic” and tropical “Malayo-Pacific” components and a “New Zealand Element” in the Pacific. The remainder are “Endemic” with no close relatives to indicate their “place of origin” and “Cosmopolitan” for those “embarrassing organisms” too widely distributed to be included elsewhere. Only the ratites, tuatara, and frog were considered old enough to have used terrestrial links, the remainder having crossed over water from the terminals of dispersal pathways recognised in the classification. The colonisation of New Zealand by Australian birds in historic times were regarded as examples of this mechanism in action (Falla 1953; Fleming 1962). This view of biogeographic relationship necessarily plays down the wider perspectives used by such workers as Hutton (1872, 1904) and Croizat (1958).  相似文献   

6.
The Darwin-Oparin-Haldane “warm little pond” scenario for biogenesis is examined by using information theory to calculate the probability that an informational biomolecule of reasonable biochemical specificity, long enough to provide a genome for the “protobiont”, could have appeared in 109 years in the primitive soup. Certain old untenable ideas have served only to confuse the solution of the problem. Negentropy is not a concept because entropy cannot be negative. The role that negentropy has played in previous discussions is replaced by “complexity” as defined in information theory. A satisfactory scenario for spontaneous biogenesis requires the generation of “complexity” not “order”. Previous calculations based on simple combinatorial analysis over estimate the number of sequences by a factor of 105. The number of cytochrome c sequences is about 3·8 × 1061. The probability of selecting one such sequence at random is about 2·1 ×10?65. The primitive milieu will contain a racemic mixture of the biological amino acids and also many analogues and non-biological amino acids. Taking into account only the effect of the racemic mixture the longest genome which could be expected with 95 % confidence in 109 years corresponds to only 49 amino acid residues. This is much too short to code a living system so evolution to higher forms could not get started. Geological evidence for the “warm little pond” is missing. It is concluded that belief in currently accepted scenarios of spontaneous biogenesis is based on faith, contrary to conventional wisdom.  相似文献   

7.
Gregory Bateson was welcomed into Biosemiotics as one of its precursors along with C. S. Peirce and Jacob von Uexküll He certainly endorsed Peirce pragmatic concern with learning as an essential characteristic of mammalian life, and also endorsed von Uexküll’s notion that the fundamental unit of animate existence is organism plus econiche. But he was at odds both with the subjectivism and with the cognitivism that connects Peirce to von Uexküll. Bateson rests his case on information theory which, he believes replaces many metaphysical notions that were the background to Peirce and von Uexküll’s approaches to ‘meaning.’ His idea of cybernetic ‘feedback’ in information circuits or networks yields a new understanding of recursiveness. Yet biofeedback in mammalian interaction had to be wrestled away from technical cybernetics and its thermodynamic rules about information, for the latter payed no attention to ‘meaning’ (“Bioentropy” section). Of the contrasts between Peirce and Bateson, the most significant is that Bateson regards ‘difference’ as primary to perception, while Peirce is concerned with continuity as primary from perception to cognition. This contrast is at the heart of Bateson’s Korzybski Lecture (see “On the Title of ‘Steps’” section), and shows how ‘difference’ in Learning develops orders and levels (see “Memory and Learning” section) leading to different categories of learning. With regard to perception, Bateson argues that the processes of perception do not bind perception to conscious awareness in any exclusive sense. Further, patterns of perception are not bounded by the skin for they include all external pathways along which information can travel. This recursive activity develops ‘agency’ (“Perception and Consciousness” section). We are ourselves interact with living mental ‘things’ but interactions with animate ‘creatura,’ is not the same as the objective interactions we purse in measuring inanimate material ‘things’ (pleroma) (“How Bioentropy Informs Bateson’s Notions of Pleroma and Creatura ” section). The grasping of context in communicative interaction, for example, is unique to creatura (“Context in Recursive Communication” section). Recognition of ‘difference’ occurs through communicative interactions and is meta-physical (without dimension). The pattern of interaction is the ‘thing,’ and ostensive aspects of communication are contextual, inclusive of all ‘external’ aspects vital for interpretation of ‘signals’ between initiators and responders to messages. Towards the end of his life, Bateson’s concerns with non-human conditions of ‘meaning’ and ‘mind’ in nature, resulted in his dropping several of the Peirce’s conditions of semiosis, as he looks at ‘meaning’ without language. He rests his method the propositional order of Peirce’s abduction rather than the latter’s full array of abduction, induction and deduction. Bateson is supported by the Biosemantics of Ruth Millikan, this paper will argue, who also believes that the derivation of meaning in animals through natural signs requires the stripping away of any ‘meaning rationalism’ (“Meaning Rationalism” section). Together they provide joint conclusions about as sign use in the ecosystems of creatura (“Conclusion” section).  相似文献   

8.
Qian Li 《Palaeoworld》2018,27(4):490-505
New cricetid (Cricetops dormitor, Eocricetodon sp., Eucricetodon cf. E. wangae, Pappocricetodon schaubi) and dipodid (Allosminthus gobiensis n. sp., Allosminthus ernos, Allosminthus uniconjugatus, Allosminthus cf. A. majusculus, Primisminthus shanghenus, Sinosminthus sp.) occurrences from the “Lower Red”, “Middle Red”, “Middle White” and “Upper White” beds of the Erden Obo section in Nei Mongol, China are reported. They are first discovered in these horizons. On the basis of the comparison of the rodent assemblages, we consider that the age of the “Upper White” beds is early Oligocene, the age of the “Middle Red” and “Middle White” beds is probable more similar to the age of late Eocene Houldjin Formation and lower part of Chaijiachong Formation, and the age of the “Lower Red” beds is correlative to the Sharamurunian. The diversity of ctenodactyloid, dipodid, and cricetid appears to change, and the turnover in rodent fauna possibly responded to the environmental and climate change towards the end of middle Eocene.  相似文献   

9.
The proximate/ultimate distinction in the multiple careers of Ernst Mayr   总被引:2,自引:0,他引:2  
Ernst Mayr's distinction between “ultimate” and “proximate” causes is justly considered a major contribution to philosophy of biology. But how did Mayr come to this “philosophical” distinction, and what role did it play in his earlier “scientific” work? I address these issues by dividing Mayr's work into three careers or phases: 1) Mayr the naturalist/researcher, 2) Mayr the representative of and spokesman for evolutionary biology and systematics, and more recently 3) Mayr the historian and philosopher of biology. If we want to understand the role of the proximate/ultimate distinction in Mayr's more recent career as a philosopher and historian, then it helps to consider hisearlier use of the distinction, in the course of his research, and in his promotion of the professions of evolutionary biology and systematics. I believe that this approach would also shed light on some other important “philosophical” positions that Mayr has defended, including the distinction between “essentialism: and “population thinking.”  相似文献   

10.
《Anthrozo?s》2013,26(4):360-366
Abstract

The Bahamas suffers from nuisances caused by roaming dogs. Although Bahamians tolerate their presence, in an economy which is dependent upon tourism, the reactions of tourists to roaming dogs is of great consequence. This study reports the reactions of 439 American tourists concerning roaming dogs in New Providence. Forty-five percent of the tourists saw roaming dogs, and of these, 40% reported that they felt “no reaction” to the dogs. However, 3% of the tourists were actually bothered by the dogs, and for 8% the sight of them changed the tourists' view of The Bahamas. Ten percent of tourists would not like to see animal control officers at work even though 23% thought The Bahamas has a roaming dog “problem.” Overall, it appears that while roaming dogs are seen by many tourists, only a small number are particularly upset by them. However, the general reaction to the dogs is unfavorable. About 1% of the tourists appeared to have been particularly upset by the roaming dogs, but 97% said that they would either return to the Bahamas again or recommend it to their friends/relations.  相似文献   

11.
Starch-slab gel electrophoresis showed two patterns of peroxidase isoenzymes in the polymorphic taxon. Xanthium strumarium L. The “strumarium” morphological complex (X. strumarium, in the sense of Millspaugh and Sherff), the putative indigenous plants of the Old World, contained a different pattern from that shown by putative introductions from the New World. Experimental F1 hybrids between “strumarium” and other complexes, “italicum-pennsylvanicum”, “chinense”, “oviforme” and “cavanillesii”, had the peroxidase pattern of the American plants. These peroxidase isoenzyme patterns were not influenced by the environmental growing conditions, but, along with partial genetic incompatibility, support the taxonomic separation of X. strumarium from other taxa of section Euxanthium.  相似文献   

12.
As treatments for malignancies have improved incrementally over the preceding decades, patients with cancer have been encouraged to reject an attitude of hopelessness and to choose instead the role of fighters. The recasting of the cancer patient as warrior and winner, upheld through the Livestrong movement, reaches its monstrous apotheosis in the form of Walter White, the central figure in the AMC television series “Breaking Bad.” The story begins with Walt as the protagonist, but the arc of this conversion narrative transforms him into the antagonist, exploring the darkest potential of his post-diagnosis empowerment. His awareness of his own mortality enables him to take risks that his more rational, pre-cancer self would have avoided. Rather than being rendered impotent by fear of an impending death, he finds himself emboldened, liberated from behavioral norms, capable of heretofore-unthinkable violence and even murder. As Walt moves from victim to victor, the viewer realizes the perils of a survive-at-all-costs mentality and is forced to question their own, initially sympathetic perception of Walt. The series subverts the notion of the cancer patient made noble through struggle by portraying a man betrayed by his own body who then becomes willing to betray everything else in the amoral service of his pride.  相似文献   

13.
Mice irradiated with lethal doses of total body X-irradiation are very susceptible to Staphylococcus aureus. A difference in virulence between a “mouse-virulent” strain and a “mouse-non-virulent” strain which lacks cell-wall aggressin could nevertheless be demonstrated. The virulence of the “mouse-non-virulent” strain could be increased by adding a cell-wall preparation with aggressin-activity (DOCR) from a “mouse-virulent” strain to the inoculum. When injected together with a dose of bacteria lower than the minimum pus-forming dose a lesion-enhancing effect of DOCR from a “mouse-virulent” strain was also demonstrated in man.  相似文献   

14.
Bernard Laurin 《Geobios》1981,14(2):253-259
New features are detected on the marginal edges of the valves of rhynchonelloid brachiopods belonging to the“Rhynchonella” phaseolina DESL. and Parvirhynchia minuta (BUV.) group. They are described as hinge pouchs and commissural grooves on the shell of “R.” cf. phaseolina, a new found member of the group from the lower Bathonian of Nièvre (France). Fonctionnal, ontogenetic and taxinomic implications must be considered.  相似文献   

15.
Nearly 2% of the specimens of the mudflat snail, Nassarius obsoletus, collected during June and July of 1972 from southern New Jersey has been found to be parasitized by sporocysts of the trematode Zoogonus rubellus. This parasite causes what is essentially total parasitic castration of this estuarine mollusc. The gonads of the hosts are almost completely absent and in their place, large, vacuolated Leydig cells fill the spaces not occupied by parasites on the periphery of the digestive glands. There is no doubt that the snails would have been sexually mature at the time of collection since all noninfected specimens included either fully developed ova or sperm.It is postulated that the destruction of the host's gonad has resulted from what is being designated as “direct chemical castration,” i.e., the sex cells are destroyed by some substance secreted by the parasite rather than as the result of direct mechanical damage.Since N. obsoletus also serves as the intermediate host for the avian schistosome Austrobilharzia variglandis, the etiologic agent for “swimmer's itch” in the same area, the potential importance of Z. rubellus as a biological control agent against A. variglandis is raised.  相似文献   

16.
Abstract

Tectonostratigraphic terranes of New Zealand, grouped for purposes of the present discussion into six groups, are briefly reviewed as to their role in the biogeographic evolution of the present day biota of New Zealand. Of all the terranes so far recognised, only the Torlesse (Rakaia) terrane is thought to have originated outside the New Zealand region; of the various models proposed to explain its origin and emplacement, only that by McKinnon (1983) would allow it to have acted as a “raft” that could have transported a biota en masse. The former existence of a “lost continent” (Pacifica), suggested as apossible source for Torlesse sediments, is regarded as improbable. The long time (at least 140 Ma, and probably 190 Ma) since terrane accretion, and the extreme degree of geological (and geographical) complexity and change that New Zealand has undergone since accretion, make it most improbable that the present day distribution of plants and animals among the terranes reflects the original distribution of their ancestors.  相似文献   

17.
Despite much effort towards resolving the molecular phylogenetic tree for pitvipers, some aspects remain unresolved. In particular, the sister group of the diverse New World radiation has remained impossible to identify with any certainty. In this study, which for the first time includes nuclear intron data from all major groups of Asian pitvipers as well as representatives of the New World radiation, Bayesian inference allows Gloydius to be identified as the most likely sister group to the New World radiation and sheds light on other ambiguous relationships among the Old World pitvipers. The sister group relationship of “Ovophisokinavensis and “Trimeresurusgracilis is confirmed by the addition of nuclear genes, and we hypothesise that they form a sister group to the Gloydius + New World clade, best supported when the phylogenetic signal from gaps is included in the form of a simple-coded matrix.  相似文献   

18.
19.
Anurans (Amphibians) from the Late Pleistocene (“Villafranchian”) of Jebel Irhoud (“Ocre” quarry), Morocco. The Villafranchian anurans of Jebel Irhoud (“Ocre” quarry) Morocco, belong to the Discoglossidae (Baleaphryne), Bufonidae (Bufo cf. B. viridis, Bufo cf. B. regularis) and Ranidae (Rana sp.). The presence of Pelodytidae (Pelodytes) in this site is possible but not ascertained. The genus Baleaphryne is reported for the first time in Africa. Likewise, Pelodytes, if this identification proves correct, would be the first one ever found in Africa.  相似文献   

20.
During the early- to mid-twentieth century, a bitter controversy raged among researchers on photosynthesis regarding the minimum number of light quanta required for the evolution of one molecule of oxygen. From 1923 until his death in 1970, Otto Warburg insisted that this value was about three or four quanta. Beginning in the late 1930s, Robert Emerson and others on the opposing side consistently obtained a value of 8–12 quanta. Warburg changed the protocols of his experiments, sometimes in unexplained ways, yet he almost always arrived at a value of four or less, except eight in carbonate/bicarbonate buffer, which he dismissed as “unphysiological”. This paper is largely an abbreviated form of the detailed story on the minimum quantum requirement of photosynthesis, as told by Nickelsen and Govindjee (The maximum quantum yield controversy: Otto Warburg and the “Midwest-Gang”, 2011); we provide here a scientific thread, leaving out the voluminous private correspondence among the principal players that Nickelsen and Govindjee (2011) examined in conjunction with their analysis of the principals’ published papers. We explore the development and course of the controversy and the ultimate resolution in favor of Emerson’s result as the phenomenon of the two-light-reaction, two-pigment-system scheme of photosynthesis came to be understood. In addition, we include a brief discussion of the discovery by Otto Warburg of the requirement for bicarbonate in the Hill reaction.  相似文献   

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