Important Disagreement Research Articles

Peasants and Rural Laborers in Pernambuco,1955-1964

In November of 1963, a general strike paralyzed the entire sugar industry in the state of Pernambuco. An estimated 200,000 rural workers took part in the strike movement which encompassed forty municfpios (municipalities) in the sugar zone and lasted three days. Planning was centralized in Palmares (about one hundred miles southwest of Recife) at the rural union, which claimed to be an umbrella organization for unions in twenty-one municipios. When the strike was over, the sugar workers had won an 80 percent wage increase. Despite its unique scope and success, the general strike was but one manifestation of a wider rural movement that had developed in Pernambuco in the early to mid-1950s. After 1950, landowners had responded to increased demand on the internal market and higher prices for sugar and other foodstuffs by expanding and concentrating production in certain commercial products. They evicted tenants who had cultivated their land for decades and, in an effort to compete with the more capital-intensive agriculture in the South, cut costs by firing high percentages of their permanent wage-labor force. This process had an especially damaging effect on the densely populated sugar region where, in spite of the continuing stream of migrants toward Recife and the southern states, the size of the dislocated rural population grew dramatically. Many of the rural dwellers, particularly the tenants, fought eviction. Some simply refused to leave, fighting unequal battles with landowner-controlled police. Others travelled to Recife to seek legal counsel. A large portion of them, however, were forced to leave and seek out marginal lands they could clear and plant with subsistence crops, only to be evicted once again. But whatever their particular situation, both peasants and rural workers took part in a movement that radically challenged the region's social and economic structure. Writers interested in peasants and peasant movements have devoted substantial attention to this movement, engaging in a series of controversies over interpretation. Among these, the most important disagreement has been over how to analyze the different participation and importance of the rural small producer and rural proletarian sectors. Some scholars (Forman, 1971; Huizer, 1972; Moraes, 1970) have argued that the peasant small producers were the most radical because they demanded land and participated in militant land invasions. The rural laborers, on the other hand, pressed for wage increases and

The Red Queen

Maynard Smith (1976a) has given a useful alternative derivation of the prediction, from the Red Queen's Hypothesis, of the constancy of extinction. It seems appropriate, however, to note that all his conclusions are stated or implied also in my first paper on the subject (Van Valen 1973, pp. 17-19). We therefore do not seem to be in any important disagreement, as he implies. Even his lag load (Maynard Smith 1976b) is the genetical equivalent of my ecologically based environmental load (Van Valen 1973). I believe that we developed this concept independently. The Red Queen's Hypothesis, that any gain in fitness by one unit of evolution is balanced by losses in fitness by others, is most easily justified by equating realized fitness with control of trophic energy. (This is only a first approximation; I have justified the deeply but clandestinely radical approach of energetics and have given more accurate expressions elsewhere [Van Valen 1976].) More than a very small average rate of change in energy availability over geological time would give absurdly low or high values in the Paleozoic or even later. And geochemical evidence (Van Valen 1976) suggests even less change than this argument requires. Even on ecological time scales the usual approximate constancy of available energy is an important underlying part of the ancient notion of the balance of nature. The Red Queen's domain is less than universal, but first-order processes deserve first attention. Maynard Smith and I do disagree on one minor point. He says (1976a, p. 329), "The difficulty [with the zero-sum assumption for resources] is that not all evolutionary changes in a species increase its share of available resources. For example, adaptation of a prey species to escape predation need not increase its numbers and in general will not do so unless predation is a density-limiting factor." But individuals that escape predators continue to control energy, while those that succumb lose all their control. Predator-resistant phenotypes thereby come to control more energy. Selection is on the individual level here, not the group level, so it is not surprising that realized group fitness is not increased. Prospective group fitness may well be increased, but that is a very different matter (Van Valen 1976). The general approach of the Red Queen was used by Fisher, Darwin, and Lyell (Van Valen 1973). Darwin's use is even clearer in his recently published book on natural selection (Darwin 1975) than in the Origin. In fact, his analogy of wedges comes from his earliest thoughts on evolution after reading Malthus and is recorded in his third notebook, of 1838 (Darwin 1967, p. 163). Darwin's thoughts were presumably inspired by Lyell's equilibrial outlook. Everything changes, as Lyell (1832) knew from the fossil record, but everything is the same. On Lyell's use of group selection in 1832 in a shifting balance between selective extinction and presumably random creation, see Van Valen (1975). Darwin, but not Lyell, saw that such a process gives an average increase in competitive fitness, but Darwin remained true to Lyell's denial of overall upward progress of life through geologic time. Lyell's mechanism was the same as Darwin's, on a different level, and was also based on competition: the antievolutionist Lyell

Disordered Semiconductors with Controllable Properties

Techniques have been developed that provide disordered semiconducting materials having energy band tails arid electronic properties that are precisely controllable. The materials are heavily doped, closely compensated n-GaAs in which the compensation ratio can be made arbitrarily close to 1. Thus the Fermi level can be controlled within the band tail. This allows measurement of various electrical transport properties as functions of energy. There are many similarities to amorphous semiconductors but with controllability that those materials do not have. Clear evidence is found for progressively greater localization of electrons of lower energy, i.e., no sharp mobility edge. Detailed measurements show an important disagreement with theoretical predictions for the temperature dependence of the conductivity at low temperatures. A very strong dependence of the conductivity on electric field strength is found, with the nonohmic behavior extending down to a few V/cm at 4.2 K. These various properties offer applications in precision thermometry and voltage surge suppression but not as nonvolatile, bistable switches.

Analysis of the thermal noise behaviour in JG FET at low temperature

Noise measurements at 77 K performed on JG FET 2 N 4416 (Texas Instruments Corporation) show an important disagreement with theoretical expressions given by Van der Ziel. By analogy with results obtained with p-type germanium samples in the presence of a moderately high electric field, the “warm-carrier” hypothesis is made for the FET channel. Experimental results in the range 77 K–300 K fit the theoretical laws deduced from this assertion.