Genetic determinism

In several forest tree breeding operations either backward or forward selection is used, although a proper combination of both might be more advantageous. Using calculations based on quantitative genetic theory, comparisons were made between the relative merits of backward and forward selection for individual families. In backward selection the mother was chosen based on her offspring and in forward selection the best offspring was selected from the family consisting of the mother and her children. A range of heritabilities and selection inten- sities in natural forest and progeny test (the latter is a function of progeny size) were compared. It is the more favourable to select backward the higher the mother ranks. Depending on the combination of parameter values, backward selection was superior to forward selection for open pollinated progeny in 1% to 57% of the top ranking families. High intensity of selection in the forest, low herita- bility and small progeny size favoured backw...

Pathogen recognition by the plant immune system is governed by structurally related, polymorphic products of disease resistance (R) genes. RAR1 and/or SGT1b mediate the function of many R proteins. RAR1 controls preactivation R protein accumulation by an unknown mechanism. We demonstrate that Arabidopsis SGT1b has two distinct, genetically separable functions in the plant immune system: SGT1b antagonizes RAR1 to negatively regulate R protein accumulation before infection, and SGT1b has a RAR1-independent function that regulates programmed cell death during infection. The balanced activities of RAR1 and SGT1, in concert with cytosolic HSP90, modulate preactivation R protein accumulation and signaling competence.

The presumed opposition of nature and nurture has been a major concern of western civilization since its beginnings. Christian theologians interpreted Adam and Eve's eating of the forbidden fruit as the origin of an inherited 'original sin'. Saint Augustine explicitly applied the concept to human mental development, arguing that, because of original sin, children are inclined toward evil and education requires physical punishment. For centuries, it was considered parents' moral and religious obligation, not to nurture their children, in our current sense of that word, but to beat the willfulness out of them. 16thC humanists fought back, arguing that "schools have become torture chambers" while it is adults "who corrupt young minds with evil". Locke's (1690) statement that children are born as a 'white paper' was crucial in rejecting the dogma of an inborn (and sinful) nature. The original sin vs. white paper argument merged with anothe...

Homosexuality is viewed by many as a social problem. As such, there is a keen interest in elucidating the origins of homosexuality among many scholars, from anthropologists to zoologists, from psychologists to theologians. Research has shown that those who believe sexual orientation is inborn are more likely to have tolerant attitudes toward gay men and lesbians, whereas those who believe it is a choice have less tolerant attitudes. The current qualitative study used in-depth, open-ended telephone interviews with 42 White and 44 Black Americans to gain insight into the public's beliefs about the possible genetic origins of homosexuality. Along with etiological beliefs (and the sources of information used to develop these beliefs), we asked respondents to describe the benefits and dangers of scientists discovering the possible genetic basis for homosexuality. We found that although limited understanding and biased perspectives likely led to simplistic reasoning concerning the origins and genetic basis of homosexuality, many individuals appreciated the complex and interactive etiological perspectives. These interactive perspectives often included recognition of some type of inherent aspect, such as a genetic factor(s), that served as an underlying predisposition that would be manifested after being influenced by other factors such as choice or environmental exposures. We also found that beliefs in a genetic basis for homosexuality could be used to support very diverse opinions including those in accordance with negative eugenic agendas.

La question de la domination africaine en athletisme devrait etre apprehendee de maniere pluridisciplinaire. Les composantes sociales, voire familiales, culturelles, environnementales et genetiques forment un ensemble indissociable. En regard de cet enchevetrement de disciplines qui laisse entrevoir d'emblee la difficulte d'une reflexion sur le sujet, l'hypothese d'un «avantage genetique» des sportifs africains tranche avec sa seduisante commodite. L'idee selon laquelle les Africains auraient des dispositions innees pour l'athletisme n'a jamais ete clairement documentee; pourtant, elle est largement plebiscitee dans le grand public, peut-etre justement en raison de sa simplicite.

In order to find a convincing position in the ‘free will’ debate, two sorts of determinism are distinguished. The merits of encompassing determinism, which is determinism as it is usually understood, and individual determinism, which focuses on the agent, are brought to the fore. The existence of encompassing determinism cannot conclusively be proven, but it may be demonstrated, on the basis of individual determinism, that actions come about in a determined way, leaving no room for ‘free will’. In order to facilitate the discussion, recent scientific developments in such diverse fields as, e.g., quantum mechanics and neuropsychology are incorporated. Balancing the arguments, I aspire to a consistent and nuanced viewpoint, not eschewing divergent conclusions.

Hay genes para todo. O eso parece concluirse de lo que nos vienen diciendo algunos científicos y divulgadores en los últimos años, y sobre todo de lo que suele leerse en la prensa cuando ésta recoge noticias científicas relacionadas con la genética humana. Casi todos los atributos significativos del ser humano han sido relacionados causalmente con la posesión de un gen o un conjunto de genes. La inteligencia, la salud, la estatura, la felicidad, el alcoholismo, el ser una buena o mala persona, la orientación política y hasta el gusto por viajar o cambiar de ciudad, todo dependería de los genes de una forma decisiva. El genoma sería nuestro retrato más fiel. En él está en lo esencial todo lo que somos y hacemos. Y, siendo así, se abre entonces la puerta, cuando la tecnología lo permita, de una reforma radical de toda nuestra personalidad y una potenciación de las cualidades de nuestra descendencia mediante la manipulación de dicho genoma.
Los que así piensan, es decir, los deterministas genéticos, consideran que la posesión de ciertos genes implica el desarrollo (casi) inevitable de rasgos importantes que nos caracterizan como personas. Han sido proclives en especial a explicar la inteligencia o las conductas sociales problemáticas o desviadas en función de los genes que portan los individuos. Entre los más convencidos no ha sido infrecuente saltar de ahí a supuestas diferencias genéticas entre razas humanas que serían responsables de talentos y habilidades desiguales. A mediados de los noventa, el libro de Richard J. Hernstein y Charles Murray The Bell Curve (Hernstein y Murray 1994) generó una intensa polémica al defender que había una perceptible disparidad en inteligencia entre las diferentes razas. El libro sostenía también que, dado que estas diferencias en inteligencia son hereditarias y están correlacionadas con el éxito económico, resultan completamente inútiles todas las políticas sociales enfocadas a la disminución de las desigualdades socioeconómicas entre grupos raciales (para diversas réplicas que muestran la intensidad que adquirió el debate, véase Fraser (ed.) 1995).

Plant-parasitic nematodes are pests of a wide range of economically important crops, causing severe losses to agriculture. Natural genetic resistance of plants is expected to be a valid solution of the many problems nematodes cause all over the world. Progress in resistance applications is particularly important for the less-developed countries of tropical and subtropical regions, since use of resistant cultivars may be the only possible and economically feasible control strategy in those farming systems. Resistance is being considered of particular importance also in modern high-input production systems of developed countries, as the customary reliance on chemical nematicides has been restricted or has come to an end. This review briefly describes the genetic bases of resistance to nematodes in plants and focuses on the chances and problems of its exploitation as a key element in an integrated management program. Much space is dedicated to the major problem of resistance durability, in that the intensive use of resistant cultivars is likely to increasingly induce the selection of virulent populations able to “break” the resistance. Protocols of pest-host suitability are described, as bioassays are being used to evaluate local nematode populations in their potential to be selected on resistant germplasm and endanger resistant crops. The recent progress in using robust and durable resistances against nematodes as an efficient method for growers in vegetable cropping systems is reported, as well as the possible use of chemicals that do not show any unfavorable impact on environment, to induce in plants resistance against plant-parasitic nematodes.