Origin and evolution

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Mitochondrial DNA Evolution in Lagomorphs: Origin of Systematic Heteroplasmy and Organization of Diversity in European Rabbits

Mitochondrial DNA Evolution in Lagomorphs: Origin of Systematic Heteroplasmy and Organization of Diversity in European Rabbits

First, according to paleontological data, the genus Oryctolagus has not given rise to an abundant ra- diative speciation and it is now represented by a unique species, Oryctolagus cuniculus. We won- dered consequently if in this evolution mitochon- drial genetic diversity has been of limited extent or has evolved as in other genera. Moreover, the ques- tion of the origin of this genus and its relationship to Lepus and Sylvilagus is a matter of debate (Daw- son 1981). We have consequently used a classical examination of nucleotide divergence between the mtDNAs of various European rabbits, hares, and a cottontail to get a new insight into their relatedness. The second goal of our study was to examine geographical organization of mtDNA diversity among wild rabbit populations distributed over western Europe. It has even been suggested that the animals of southern Spain could be the progeny of the rabbits that were pushed back in that region at the time of glaciations and that wild populations found over France would descend from a population that took refuge in southern France (Provence) and was separated by the ice cover of the Pyrenees from the first stock (Beaucournu L980; for review see Ar- thur 1989). Immunological data (Van der Loo et al. 1990) are consistent with this view. We took ad- vantage of mtDNA to get more precise information about the history of expansion in western Europe after the ice age (including human interference).
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11 Lee mas

TítuloBirth and death evolution with strong purifying selection in the histone H1 multigene family and the origin of "orphon" H1 genes

TítuloBirth and death evolution with strong purifying selection in the histone H1 multigene family and the origin of "orphon" H1 genes

An orphon origin was hypothesized to explain the evolutionary origin of the RI H1 subtypes from vertebrates, where the exclusion of these genes from the main histone repetitive units and consequently from the interlocus recombination or concerted evolution events, would account for the presence of this differentiation-specific subtypes solitary in the genome (Schulze and Schulze 1995). If the effect of concerted evolution on the long-term evolution of both RD and RI H1 subtypes is not significant, as revealed in the present work, it is then necessary to revisit this orphon origin hypothesis to fit it into the birth-and- death model of evolution. A brief scheme of the model of birth-and-death evolution (Nei, Gu, and Sitnikova 1997) is adapted to the concrete case of H1 genes in figure 4A. Following this model, the different H1 isoforms may have been generated by recurrent gene duplication/deletion events. Functional H1 proteins would evolve under a strong purifying selection determined by their critical structural and functional roles, which would be already operating at the time of divergence of the RI H1 genes before the differentiation between vertebrates and invertebrates, about 815 MYA (Feng, Cho, and Doolittle 1997). At the nucleotide level, H1 genes may diverge extensively through synonymous substitution events, being DNA sequences of different gene family members very different both within and between species (Nei and Hughes 1992; Nei, Gu, and Sitnikova 1997). This events proposed theoretically in figure 4A are precisely shown by real data in figure 4B. This “tree of life” shows the organization of H1 and core histone genes in model organisms as well as in many other genomes, indicating the modifications in histone organization with special attention to whether H1 genes are in the major repetitive units or solitary in the genome and if they show RI features as polyadenylation signals. The next step after the duplication events would involve the transposition of RI H1 genes to a solitary location in the genome, where they would continue their evolution in a new physical location and where new genes and pseudogenes would be generated. The presence of transposition and inversion events is very common in histone evolution, as revealed by the different histone gene orientations in the DNA strands, and a similar pattern of duplication and transposition events has been postulated to explain the long-term evolution of the multigene families of the vertebrate immune system (Sitnikova and Nei 1998).
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17 Lee mas

Prebiological evolution and the physics of the origin of life

Prebiological evolution and the physics of the origin of life

It is unlikely that the paleontological record will provide direct data on how life first appeared. There is no geological evidence of the environmental conditions on the Earth at the time of the origin of life, nor any fossil register of the evolutionary processes that preceded the appearance of the first cells. Direct information is lacking not only on the composition of the terrestrial atmosphere during the period of the origin of life, but also on the temperature, ocean pH values, and other general and local environmental conditions which may or may not have been important for the emergence of life. Moreover, the attributes of the first living organisms are unknown. They were probably simpler than any cell now alive, and may have lacked not only protein-based catalysis, but perhaps even the familiar genetic macromolecules, with their ribose-phosphate backbones. It is possible that the only property they shared with extant organisms was the structural complementarity between monomeric subunits of replicative genetic polymers able to transmit to its progeny information capable of undergoing evolutionary change. Hence, caution must be exercised in extrapolating molecular phylogenies back into primordial times. Comparative genomics is a blooming field that has an extraordinary potential for our understanding early cellular evolution, but it cannot be applied to events prior to the evolution of protein biosynthesis. Older stages are not yet amenable to this type of analysis, and the organisms at the base of universal phylogenies are ancient species, not primitive unmodified microbes.
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18 Lee mas

Origin and evolution of the planktic foraminiferal Family Eoglobigerinidae Blow, 1979, during the early Danian (Paleocene)

Origin and evolution of the planktic foraminiferal Family Eoglobigerinidae Blow, 1979, during the early Danian (Paleocene)

The zonation by Arenillas et al. (2004) in- cludes six subzones: Hedbergella holmdelensis and Parvularugoglobigerina longiapertura Subzones of the Guembelitria cretacea Zone, the Parvularugoglobigerina sabina and Eoglobigerina simplicissima Subzones of the Pv. eugubina Zone, and the Eoglobigerina trivialis and Subbotina triloculinoides Subzones of the P. pseudobul- loides Zone. As shown in Figure 1, the Zone P0 of Berggren and Pearson (2005) is equivalent to the H. holmdelensis Subzone, the Zone P α approximately spans both P. longia- pertura Subzone and Pv. eugubina Zone, and P1a and P1b are roughly equivalent to E. trivialis and S. triloculinoides Subzones respectively. In order to study taxonomic details, we also have revised the fossil material from Elles (Tunisia), Ben Gurion (Israel), Caravaca and Agost (Spain), Bajada del Jagüel (Argentine), Lynn Creek (Mississippi) and Deep Sea Drilling Project Site 305 (Shatsky Rise, North Pacific). In addition, the biostratigraphic scheme proposed in Figure 1 takes also into account other relevant K/Pg sections, such as Gubbio (Italy), Zumaia (Spain), Bidart (France), El Mulato, El Mimbral, La Lajilla, Bochil and Guayal (Mexico), and Loma Capiro (Cuba). Geographical coordinates of all strati- graphic sections are given in Appendix 1.
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19 Lee mas

Vocational guidance: origin, evolution and current state

Vocational guidance: origin, evolution and current state

psychoanalysis) and the former well represented in A. Mansilla's proposal (1973). This author combines clinical behavioural elements, psychometrics and strategies of adaptation from counseling, to South American social atmosphere. Ardila also reminds that the transcendency that governmental organisms grant to guidance (academic, voca- tional-occupational, professional and personal) reflects in important publications as La orientación educativa y profesional in Chile, Guatemala, Panama and Venezuela (1967), on the part of O. E. A. and in events like the Latin American Congress of Orientation whose Memorias have been published by the International Association of guidance (1971). As G. Marín consigns it (1987), psychodynamic psychotherapies and psychometry constituted, in the region, psychology and psychologists' points of consolidation, which in their conflicting and precarious beginnings assumed themselves as psychometers or as therapists. Vocational guidance, having the psychologist as its impeller and practically only officious possessor, shows in its beginnings this double slope, in some nations dissociated in development phases (from therapy to psychometry, or vice-versa), and in others integrated in eclectic strategies. If the sources of both resources are revised, it isn't hard to identify pedagogues' actions in the psychometric field and those of physicians in the psychotherapeutic one. Pedagogues, physicians and philosophers were the educators of the first Latin American psychologists, in the fragile departments that, housed in Philosophy, Humanities or Arts academic structures, gestated the university degree in the '40 and ' 50.
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12 Lee mas

Evolution of landslide activity, and the origin of debris flows in the El Niño affected Payhua Creek basin, Matucana area, Huarochiri, Peru

Evolution of landslide activity, and the origin of debris flows in the El Niño affected Payhua Creek basin, Matucana area, Huarochiri, Peru

The volumes of debris flows from the M1, M2 and M3 ravines in 1983 give a direct indication of the yield ratios of areas of QP basin that actually produce debris flows. Steep ravine systems along the west side of QP basin such as M1 are the primary sources of debris flows. Air photo interpretation indicates that these largely unvegetated small and steep basins are rapidly expanding into adjacent mountainsides. In contrast, the east side of the basin is dominated by steep rock or has been extensively terraced, and these terraces show no evidence of debris flow modification (Fídel Smoll et al., 2005). The areas of steep ravine systems and estimates of debris flow volumes that would be yielded from them based on yield values from M2 and M3 are presented in Table 3, A (flows from M2 and M3 are assumed to be confined on the fan immediately east of Payhua village and are not included). The total of these values represent the volume of debris flow sediment that would be introduced into the main QP channel. An additional unknown volume would be added to these figures through mobilization of channel sediments and landslide sediments. A survey of the accessible reaches of the channel of QP between the head of the QP fan and the area of Payhua village was undertaken to determine the volume stored in the channel that could be mobilized by a debris flow. Only approx. 1 km of channel had significant sediment in it out of about 2.3 km surveyed. This reach also contains the greatest concentration of landslides. The remainder of the channel was steep, largely exposed rock. The minimum estimate was 9000 m 3 of sediment in the channel assuming a fill of 1 m, or about 9 m 3 per linear m of channel. Local reaches may have three times this amount or more. The amount of sediment from the main channel that would be added to debris flows originating in sub-basins is difficult to predict and is the source of greatest uncertainty for this approach. However, the 248 040 m 3
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12 Lee mas

The Gaia  ESO Survey: The origin and evolution of s  process elements

The Gaia ESO Survey: The origin and evolution of s process elements

Among the several on-going spectroscopic surveys, the Gaia- ESO Survey (GES, Gilmore et al. 2012; Randich et al. 2013), an ESO large public survey, is providing high-resolution spectra of di ff erent stellar populations of our Galaxy using FLAMES at VLT (Pasquini et al. 2002) and employing both Gira ff e and UVES fibres in Medusa mode. This survey aims at homogeneously determining stellar parameters and abundances for a large sam- ple of stars in the field, in Galactic open clusters, and in calibra- tion samples, including also globular clusters. In particular, the high-resolution spectra obtained with UVES allow the determina- tion of abundances of a large variety of elements including many neutron-capture elements: two light s-process (ls) elements (Y, Zr), three s-process (hs) elements (Ba, La, Ce), one r-process ele- ment (Eu), and three elements with significant contributions from both processes (mixed elements – Mo, Pr, and Nd). In the present work, we investigate the evolution of the group of s-process ele- ments. The paper is structured as follows. In Sect. 2, we present the data reduction and analysis and in Sect. 3 the solar abundance scale. In Sect. 4 we describe the field and cluster samples, in Sect. 5 we show the results on the abundance of s-process ele- ments, and in Sect. 6 we discuss their time evolution. Finally, in Sect. 7 we give our summary and conclusions.
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15 Lee mas

The origin and evolution of the saraph symbol

The origin and evolution of the saraph symbol

At first sight, the sin that brought on the attack of the burning serpents in Numbers 21 (v. 6) is the Israelites’ indictment of Moses for having taken them from the fertile land of Egypt “to die in the wilderness” (v. 5). However, the Israelites express a similar protestation before (Ex 14:11–12, 16:3; Num 14:2, 16:3, 20:4) without precipitating a similar reaction of divine anger. In these precedents, the complaint is answered by mention of the power of YHWH against the Egyptians (Ex 14:13) and his ability to supply food (Ex 16:4) and water (Num 20:4). At worst, the punishment for such a grievance is none other than its fulfillment: the “complaining generation” is condemned to expire in the wilderness instead of conquering the Promised Land (Num 14:35, 26:65). For this reason, the serpent attack in Num 21:6–9 can hardly be interpreted as a divine reaction to the complaint voiced. If so, it was prob- ably triggered by a different sin that Numbers 21 silences prudently.
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28 Lee mas

Abengoa case: origin, evolution and discussion of its situation

Abengoa case: origin, evolution and discussion of its situation

The following report has a main goal to offer the reader the bases to identify possible aspects which can be the key to determine a situation of financial insolvency that is happening in the company nowadays. In a general way we can remember that Abengoa was born with its first founder Javier Benjumea as a company devoted to make projects of industrial and electric installations but, through the years the company belongs to its first-born such as Felipe Benjumea. These opted for a strategic change consisted of transforming a company of projects in to another of productive assets owner. That is to say, the former business was left. It consisted of awarding projects by contest, the financing by credits for circulating and the charge through certifications which had a controlled debt and a controlled risk. The new activity is acquires productive plants which guarantied future incomes. To this point the strategic change of the company can be understood as a greedy project with views of the future, international expansion and growing, the problem arises when we look into the means to get it. The company following the economic flows of the moment adopted the premise of growing into debt. When we observe the analysis which has been done throughout all this report, we can claim that the financial charge in the business operation has been excessive and has finished harming the activity to the point that they cannot face the payment obligations. The level of debt that in a first moment could generate bigger sources to make projects thanks to the leverage effect, with the current situation has ended in an insolvency situation.
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50 Lee mas

Evolution and phylogeny of Rhizobia

Evolution and phylogeny of Rhizobia

ABSTRACT. Nitrogen fixation is an ancient process that may have originated in the archaean Eon under the primitive atmo- sphere anoxygenic conditions. Diazotrophy is an exclusive process of prokaryotes, only Euryarchaeota and 6 of over 50 Bacteria phyla have diazotrophs lineages. Some of them coevolved with flowering plants for the establishment of molecular bases of a mu- tualistic symbiosis relationship. In rhizobia, nitrogen fixation oc- curs inside the nodules, special structures on the roots or stems of legumes. Nodule organogenesis starts with the bacterial nodula- tion factors (Nod factors) codified in large plasmids or symbiotic islands in the bacterial genomes. Nodulation genes had a more re- cent origin than the nitrogen fixation ones because the origin of the nod genes is associated with the origin of the hosts. The rrs phylogeny groups rhizobia in seven genera of the α -Proteobacte- ria: Bradyrhizobium, Mesorhizobium, Rhizobium, Sinorhizobium, Azorhizobium, Methylobacterium and Devosia, and two genera re- cently described in β -Proteobacteria: Burkholderia and Wautersia. The phylogenies obtained with other chromosomal genes are sim- ilar at the genus level, but it is incongruent with the symbiotic gene (nif & nod) phylogeny, because horizontal gene transfer has allowed their evolution in relation to the legume host fitness.
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19 Lee mas

Evolution Oriented Monitoring oriented to Security Properties for Cloud Applications

Evolution Oriented Monitoring oriented to Security Properties for Cloud Applications

The addition of the most abstract monitoring level allows obtain- ing information that cannot be obtained using normal application monitoring. In particular, the IPS allows our model to deal with potential problems caused by the interaction between different ap- plications in the same platform. For example, if the frequency of correlation between events generated in two monitored applica- tions is statistically significant our model may conclude that there is an unforeseen interaction between those applications and take appropriate measures. On the other hand, GAS supports mainte- nance and evolution of specific applications and detect problems with non-compliant implementations, as well as problems in the modeling. With an isolated application, monitoring can detect a fail- ure, which is by definition an inconsistency between the model and the implementation of the application (considering that it includes all supporting layers of the cloud stack). However, it is not possible to determine whether the problem is actually in the model or in the implementation. With the vertical monitoring that GAS per- forms over different instances of the same application, our model can indeed determine the origin of the inconsistency. Suppose that GAS receives, from a given application instance, events indicating repeated violations of a monitoring rule indicating an illegal transi- tion between two states. This would indicate that the application instance does not conform to its application model. On the con- trary, if the violations come from different instances of the same application, these violations would most likely indicate an error in the model of the application.
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7 Lee mas

Emergence and Evolution of Cooperation Under Resource Pressure

Emergence and Evolution of Cooperation Under Resource Pressure

The results offered by the CURP model have interesting consequences for analysing human social behaviour related to cooperation. As explained in the first few pages, cooperation is a paramount element for understand- ing human social relationships and the development of sociality. HG societies may implement a wide variety of strategies that can change according to different elements such as the general socio-ecological context, in which different population densities deal with distinct distributions and concentrations of resources, socio-historical dynamics and internal social changes. CURP parametrises both the probability of finding resources and the need for a specific amount of energy for survival, reproducing what might be the different socio-ecological settings that HG societies faced throughout human evolution and world colonisation. Although technology and production have been traditionally argued as the main factors that explain human capabilities to face new landscapes or changing resource availability, the results suggest that a modification of distribution and consumption patterns allow HG societies to deal with changing resource availability.
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10 Lee mas

Great ape genomics : diversity and evolution

Great ape genomics : diversity and evolution

Orangutans (Malay word meaning the man of the forest) are our most distant relatives and are classified in two different species, the Sumatran orangutans (Pongo abelii) and Bornean orangutans (Pongo pygmaeus). This range has been changing over time since the area known as Sundaland (Malay Peninsula, Java Sumatra and Borneo) have been joining and separating repeatedly. There are no subspecies of the Sumatran orangutan but there are three in Borneo: P.p. pygmaeus in northwest Borneo, P.p. wurmbii in central Borneo and in northeast of the island ranges P.p. morio. The geographical conditions in Borneo have shaped this species and besides genetic support for this division there are size differences between the subspecies. Orangutans are characterized by its reddish-brown hair and grey-black skin. They spend most of their time hanging in trees and for this reason they are equipped with very long and strong arms opposed to short and bowed legs. Their feet are mostly adapted to the trees and allow them to grip on branches. Given this arboreal adaptation and unlike gorillas and chimpanzees, orangutans are not true knuckle-walkers, and they move in the ground using their fists. Both species are large and show great sex dimorphism. In terms of weight, adult males get to 75kg while females around 40kg. They are the least social species among great apes and live mostly a solitary lifestyle. Their diet is mostly based on fruits that they find opportunistically and changes from month to month.
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93 Lee mas

Classification and phylogeny in human evolution

Classification and phylogeny in human evolution

ABSTRACT . The competing claims and requirements of classification (episte- mological) and phylogeny (ontological) are briefly reviewed. Classification is a product of systematists, while phylogeny is a product of nature. For paleon- tologists the principal source of information about the evolutionary histories of groups of organisms is morphology, yet speciation and morphological shift are far from synonymous. This simple fact complicates everything from basic species recognition to phylogeny reconstructions involving higher taxa. It is concluded that in the interests of stability, simplicity, and effectiveness of communication, classifications should be consistent with what is known or can reasonably be inferred about phylogeny, but need not be exact translitera- tions of it. In the case of human beings and their close relatives it is clear that the evolutionary story has not been a simple linear process, but has instead involved extensive experimentation, with the production of numerous termi- nal species. These species must be accounted for in any classification that claims consistency with the fossil record.
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6 Lee mas

AB Biotics: analysis of a company in expansion

AB Biotics: analysis of a company in expansion

Following the financial part, we will focus on the form of borrowing that has the company. So we made a line graph that shows the proportion of debt that supports the company in which is observed that indebtedness is higher with the passage of time, although he suffered variations in these 4 years. We focus on the total indebtedness, an ideal percentage could be between 40-60%. Low levels of indebtedness are that the company may be incurring an excess of idle capital, and loss of profitability. On the contrary, high values would mean borrowing too much. With this situation the company can have a decapitalization and with it a loss of autonomy against third parties. Thus, as shown in the graphic 11 can establish the entity subject to the 3 first years of study, instead in 2015, the company has a high percentage of debt. His percentage slash 95% with what the company is at a critical point since this result means that liabilities are close to being equal to the equity and has risk the company suffer a decapitalization. The cause of this high percentage is basically by an increase in borrowing in the short term by 30% where this growth is focused on suppliers and creditors of the company.
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38 Lee mas

TítuloNotes on the origin and significance of stone layers

TítuloNotes on the origin and significance of stone layers

quartz reef) the layers are allochthonous, for the coarse debris has been transported downs- lope. These occurrences show that stone layers are forming at present and in a range of climatic environments; though in each instan- ce in association with torrential rains, with a 'storm' event (see also FAIRBRIDGE and FINKL, 1984). The carpets contain a mix of coarse and fine fragments, and are only a few centimetres thick. They differ both in thick- ness and shape (angularity) from the alluvial covers (figure 4a) preserved on the Hayward pediment, north of the Edeowie H.S., in the western piedmont of the Flinders Ranges (TWIDALE, 1979, 1981; BOURNE and TWIDALE, 1998). The latter were deposited by divaricating rivers debouching from the uplands to the east. The scarp-foot areas unaf- fected by distributary streams, however, are distinguished from the coarse, rounded, partly exotic detritus distributed by debou- ching rivers by their local origin (the backing limestone scarp), their small calibre and their angularity.
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15 Lee mas

TítuloHorace R  Blank and the origin of rock doughnuts

TítuloHorace R Blank and the origin of rock doughnuts

Rock doughnuts are annular rims situa- ted around rock basins that for varying pe- riods are occupied by pools of water (fig. 1). The term was introduced by Horace Blank (1951) who had noted examples of the lan- dform on granite hills in central Texas, and elsewhere in the United States (see Thor- nbury, 1954: 70). Blank (1898-1984) was at the time a Professor of Geology in the then Agricultural and Mechanical College of Texas, the institution that has evolved into the Texas A. and M. University (Popp 1987). Though primarily a mineralogist, his geolo- gical interests were wide ranging and inclu- ded landscape, for his publications include papers on a landslide, incised meanders, and granite weathering, as well as a pioneering investigation of rock doughnuts. Blank was imaginative in his analysis of the forms, and his investigative method was exemplary, for he proposed various possible explanations of the features he had observed and then considered and tested each against his field evidence.
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27 Lee mas

Trend analysis of CO2 and CH4 recorded at a semi-natural site in the northern plateau of the Iberian Peninsula

Trend analysis of CO2 and CH4 recorded at a semi-natural site in the northern plateau of the Iberian Peninsula

an interquartile range of 11.9 ppm. For the 8.3-m level, concentra- tion was 0.6 ppm lower and the interquartile range 1.6 ppm nar- rower. Observations for the lowest level are presented in Fig. 1 (a) where the seasonal pattern is revealed by noticeable values in spring and low values in summer. Large measurements could be explained by plant respiration during the growing season together with the formation of a stable boundary layer during the night. Occasional emissions from vehicles used in farming around the site should not be excluded. However, the low values observed in summer may be attributed to the lack of vegetation in this season. For CH 4 , median concentration was 1.899 ppm at the lowest
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10 Lee mas

Evolución mitos errores conceptuales desafíos y soluciones

Evolución mitos errores conceptuales desafíos y soluciones

Darwin’s only comment about the “origin” of species is “. . . if (and oh what a big if) we could conceive in some warm little pond with all sorts of ammonia and phosphoric salts, -- light, heat, electricity, etc. present, that a protein compound was chemically formed, ready to undergo more complex changes . . .”

24 Lee mas

Evolution, embryology, and Ernst

Evolution, embryology, and Ernst

powerful minds around, despite his protestations of age and lack of the same energy he had shown throughout his long and distinguished career. The same thing had happened when I visited Harvard in 1983-1984. Mayr set me up in office space at the Museum of Comparative Zoology were philosopher of biology Michael Ruse and I shared the back of a huge storage area, equipped with old wooden desks and an ancient telephone that looked as though they had all been there almost as long as the dusty boxes of brachiopods that filled the metal shelves behind us. Mayr was, of course, retired by then and was deeply engaged in his historical and philosophical study of biology. He welcomed me into his office for discus- sions, always starting with the caveat that he knew little about the history of embryology on which I was focused. Then he would pull out reprints, articles, books, and even his old notes about all the important works and ideas in the history of study of individual development. Study of individ- ual development is not irrelevant to understanding evolutionary devel- opment, and Mayr was fully aware of that. He was a generous and invaluable source of ideas during my year as a new assistant professor, working on my first major projects in the then-neglected history of em- bryology. His weekly evening discussion sessions provoked lively ex- changes covering all topics related to evolution, including developmental and genetics questions. He was always the one bringing in new ideas, wanting to discuss a book he had just read, or enticing us to think about deeper issues.
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9 Lee mas

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