遗传变异产生的分子机制

遗传变异产生的分子机制孙毅查理士·达尔文（Ｃ．ＲＤａｒｗｉｎ）在接受前人进化思想和科学成就的基础上,运用自己环球旅行中获得的丰富进化证据,进行了科学总结。他在物种形成问题上提出了三个因素：即变异、遗传和自然选择。现代达尔文主义学派基本上同意经典达尔文...     

再谈“有希望的怪物”

1933年,遗传学家Goldschmidt提出＂有希望的怪物＂假说,以解释宏演化（macroevolution）中有别于＂达尔文式＂的演化机制。近年来,有关内共生和基因倍增等进展表明,＂有希望的怪物＂在自然界中其实非常普遍。这虽然与＂现代综合进化论＂的观点不甚一致,但却能在经典达尔文主义找到契合点：作为自然选择的补充,＂有希望的怪物＂可以为宏演化提供一种潜在的候选机制。这种建立在多元论基础上的进化观是达尔文留给后人最宝贵的遗产。     

介绍达尔文主义

达尔文主义是一门研究生物界发展历史和进化规律的科学。这门科学的创始人是伟大的学者达尔文。苏联先进的米丘林科学是达尔文主义发展到最高的阶段,也就是创造性的达尔文主义。因此,要学习现代的米丘林科学,必须学习达尔文主义;达尔文主义是米丘林科学的基础。中央农业部主办的“米丘林农业植物选种及良种繁育讲习班”,在请苏联专家伊万诺夫主讲“米丘林遗传选种与良种繁育学”的同时,特地又邀请了刚来我国讲学的杜伯罗维娜专家讲授“达尔文主义”。杜伯罗维娜专家是北京师范大学和     

关于获得性遗传的问题

在高中教材“达尔文主义基础”是第117页有一节是“获得性的遗传为什么不显著?”关于这一问题在教学过程中,很多同学与教师往往不能把它与获得性遗传的问题统一起来看。有些人总认为这两个问题是对立的,是矛盾的。认为获得性遗传既然有不显著的现象,那末获得性能够遗传这一观点就有疑问。或者有人这样问:“既然获得性能够遗传,但又为什么会有不显著的现象发生呢?”另外还有些教师,基本上是承认获得性能遗传,但对获得性遗传的现象,以及获得性不显著     

进化论系列讲座（十七） 达尔文主义与新达尔文主义

正如前所述,赫胥黎、海克尔和斯宾塞三位"大咖"通过各自的学术活动捍卫和发展了达尔文进化论的核心思想,但是在他们活跃的学术生涯前期却并没有出现"达尔文主义"一词。直到达尔文逝世7年后,华莱士在1889年出版了《达尔文主义》一书,从此这个用语开始广为流传。华莱士写这本书的目的是希望借此推进一种"纯粹的"达尔文主义。它排除了达尔文的泛生论以及其他所有承认获得性状遗传的内容,华莱士在书中提到:"……我的所有工作力图展示出在新物种产生的过程中自然选择压倒性的重     

现代综合进化论

现代达尔文主义学派的兴起查理士·达尔文划时代的巨著《物种起源》1859年发表后,标志着进化论的诞生。在达尔文的生物进化论问世之后,出现了两个不同的研究方向,得出了不同的结论。摩尔根学派认为:染色体及排列其上的基因是遗体的物质;米丘林学派则反对有特殊的遗传物质,认为细胞质内一点一滴的活质都具有遗传性的作用。摩尔根学派认为遗传的变异必须通过遗传物质结构的改变,环境所引起的表型改变是不遗传的,从而反对获得性遗传的主张;米丘林学派从新陈代谢为生命的基本特征的观点出发,根据生物体与生活条件统一的原理,强调环境条件能够改变生物的性状,当同化作用影     

神经达尔文主义：神经元群选择理论

神经达尔文主义：神经元群选择理论神经达尔文主义（ＮｅｕｒｄＤａｒｗｉｎｉｓｍ,ＮＤ）是美国的埃德尔曼（Ｇ．Ｍ．Ｅｄｅｌｍａｎ）提出的,其主要思想借鉴了达尔文的自然选择学说,试图创立三种解释脑的感知及高级认知功能的理论框架。它认为由神经元通过紧密互联组...     

我国在达尔文以前关于遗传性、变异性和人工选擇的研究

我们知道,达尔文主义是达尔文创立的米丘林学说指出了控制进化的可能性。达尔文在人工选择和自然选择的原理中分析了变异、遗传和选择的相互联系,肯定了人工选择和自然选择的创造性作用。米丘林学说从生物体跟生活条件统一的基本原则,联系着生活条件,研究了遗传性及其变异性的一些规律,肯定了用控制生活条件和其他方法定向改造生物的可能性,把达尔文主义向前推进了一步。但是,达尔文主义跟其他科学一样,都是在社会发展的过程中,在人类对于客观世界的知识逐渐累积起来的基础上逐渐发展起来的。     

达尔文进化论的科学本质与贡献

自达尔文1859年发表《物种起源》一书以来,“进化”已逐渐成为生物学文献中出现频率最高的词汇之一。随着科学界对生物进化现象的认识逐渐深入,人们对达尔文进化论的理解也在不断深化和提高。从魏斯曼等人提出“新达尔文主义：到摩尔根等人以“粒子遗传”替代“融合遗传”的概念以及费希尔、霍尔丹和赖特等人创立群体遗传学,     

解放后达尔文主义在我国的发展

解放前,由于反动统治者不重视科学的发展,达尔文主义作为一门独立的生物科学实质上是不存在的。虽然达尔文学说介绍到我国后,也曾引起一些进步学者,如鲁迅等的零散的宣扬,但仅能邀得少数的同情者而已。嗣后莫尔根学说传入我国,这一科学逐渐为新达尔文主义所取代,但我国的新达尔文主义者也只是寥若晨星,屈指可数。他们不仅在科学研究上鲜有建树,而且在达尔文主义的介绍上也大抵限于片断的知识,缺乏严正的科学体系。因此,在解放前我国的达尔文主义还未能形成一个独立学科。解放后,科学事业在党的英明领导和亲切关怀下获得了飞跃的发展,伟大盟邦苏联首先支援了我国生物科学部门中的薄弱环节,1950年苏联达尔文主义专家绥吉纳应邀在北京农业大学系统讲授达尔文主义,并两次举办了达尔文主义研究班,是为达尔文主义在我国传播之先声。1952年苏联遗传选种专家伊万诺夫,达尔文主义专家杜勃洛维娜又先后在北京系统传     

Lamarckism and epigenetic inheritance: a clarification

Since the 1990s, the terms “Lamarckism” and “Lamarckian” have seen a significant resurgence in biological publications. The discovery of new molecular mechanisms (DNA methylation, histone modifications, RNA interference, etc.) have been interpreted as evidence supporting the reality and efficiency of the inheritance of acquired characters, and thus the revival of Lamarckism. The present paper aims at giving a critical evaluation of such interpretations. I argue that two types of arguments allow to draw a clear distinction between the genuine Lamarckian concept of inheritance of acquired characters and transgenerational epigenetic inheritance. The first concerns the explanandum of the processes under consideration: molecular mechanisms of transgenerational epigenetic inheritance are understood as evolved products of natural selection. This means that the kind of inheritance of acquired characters they might be responsible for is an obligatory emergent feature of evolution, whereas traditional Lamarckisms conceived the inheritance of acquired characters as a property inherent in living matter itself. The second argument concerns the explanans of the inheritance of acquired characters: in light of current knowledge, epigenetic mechanisms are not able to drive adaptive evolution by themselves. Emergent Lamarckian phenomena would be possible if and only if individual epigenetic variation allowed the inheritance of acquired characters to be a factor of unlimited change. This implies specific requirements for epigenetic variation, which I explicitly define and expand upon. I then show that given current knowledge, these requirements are not empirically grounded.     

The Contributions – and Collapse – of Lamarckian Heredity in Pasteurian Molecular Biology: 1. Lysogeny, 1900–1960

This article shows how Lamarckism was essential in the birth of the French school of molecular biology. We argue that the concept of inheritance of acquired characters positively shaped debates surrounding bacteriophagy and lysogeny in the Pasteurian tradition during the interwar period. During this period the typical Lamarckian account of heredity treated it as the continuation of protoplasmic physiology in daughter cells. Félix d’Hérelle applied this conception to argue that there was only one species of bacteriophage and Jules Bordet applied it to develop an account of bacteriophagy as a transmissible form of autolysis and to analyze the new phenomenon of lysogeny. In a long-standing controversy with Bordet, Eugène Wollman deployed a more morphological understanding of the inheritance of acquired characters, yielding a particulate, but still Lamarckian, account of lysogeny. We then turn to André Lwoff who, with several colleagues, completed Wollman’s research program from 1949 to 1953. We examine how he gradually set aside the Lamarckian background, finally removing inheritance of acquired characters from the resulting account of bacteriophagy and lysogeny. In the conclusion, we emphasize the complex dual role of Lamarckism as it moved from an assumed explanatory framework to a challenge that the nascent molecular biology had to overcome.     

The Case of Paul Kammerer: Evolution and Experimentation in the Early 20th Century

To some, a misguided Lamarckian and a fraud, to others a martyr in the fight against Darwinism, the Viennese zoologist Paul Kammerer (1880–1926) remains one of the most controversial scientists of the early 20th century. Here his work is reconsidered in light of turn-of-the-century problems in evolutionary theory and experimental methodology, as seen from Kammerer’s perspective in Vienna. Kammerer emerges not as an opponent of Darwinism, but as one would-be modernizer of the 19th-century theory, which had included a role for the inheritance of acquired characteristics. Kammerer attempted a synthesis of Darwinism with genetics and the chromosome theory, while retaining the modifying effects of the environment as the main source of favorable variation, and he developed his program of experimentation to support it. Kammerer never had a regular university position, but worked at a private experimental laboratory, with sidelines as a teacher and a popular writer and lecturer. On the lecture circuit he held forth on the significance of his science for understanding and furthering cultural evolution and he satisfied his passion for the arts and performance. In his dual career as researcher and popularizer, he did not always follow academic convention. In the contentious and rapidly changing fields of heredity and evolution, some of his stances and practices, as well as his outsider status and part-Jewish background, aroused suspicion and set the stage for the scandal that ended his career and prompted his suicide.     

Freud’s Lamarckism’ and the Politics of Racial Science

This article re-contextualizes Sigmund Freud’s interest in the idea of the inheritance of acquired characteristics in terms of the socio-political connotations of Lamarckism and Darwinism in the 1930s and 1950s. Many scholars have speculated as to why Freud continued to insist on a supposedly outmoded theory of evolution in the 1930s even as he was aware that it was no longer tenable. While Freud’s initial interest in the inheritance of phylogenetic memory was not necessarily politically motivated, his refusal to abandon this theory in the 1930s must be understood in terms of wider debates, especially regarding the position of the Jewish people in Germany and Austria. Freud became uneasy about the inheritance of memory not because it was scientifically disproven, but because it had become politically charged and suspiciously regarded by the Nazis as Bolshevik and Jewish. Where Freud seemed to use the idea of inherited memory as a way of universalizing his theory beyond the individual cultural milieu of his mostly Jewish patients, such a notion of universal science itself became politically charged and identified as particularly Jewish. The vexed and speculative interpretations of Freud’s Lamarckism are situated as part of a larger post-War cultural reaction against Communism on the one hand (particularly in the 1950s when Lamarckism was associated with the failures of Lysenko), and on the other hand, against any scientific concepts of race in the wake of World War II.     

Weismann Rules! OK? Epigenetics and the Lamarckian temptation

August Weismann rejected the inheritance of acquired characters on the grounds that changes to the soma cannot produce the kind of changes to the germ-plasm that would result in the altered character being transmitted to subsequent generations. His intended distinction, between germ-plasm and soma, was closer to the modern distinction between genotype and phenotype than to the modern distinction between germ cells and somatic cells. Recently, systems of epigenetic inheritance have been claimed to make possible the inheritance of acquired characters. I argue that the sense in which these claims are true does not challenge fundamental tenets of neo-Darwinism. Epigenetic inheritance expands the range of options available to genes but evolutionary adaptation remains the product of natural selection of ‘random’ variation.     

Further evidence for Darwin's pangenesis.

Darwin's pangenesis, a developmental theory of heredity, has been largely thought to be wrong for more than a century. In this paper, further evidence for the inheritance of acquired characters and graft hybridization is provided. A striking similarity between mRNA and Darwin's so-called gemmule has been found by comparing their nature and function. I propose that once the term gemmule has been replaced by mRNA, Darwin's pangenesis will revive, indicating an important step in biology.     

Formalizing Darwinism and inclusive fitness theory

Inclusive fitness maximization is a basic building block for biological contributions to any theory of the evolution of society. There is a view in mathematical population genetics that nothing is caused to be maximized in the process of natural selection, but this is explained as arising from a misunderstanding about the meaning of fitness maximization. Current theoretical work on inclusive fitness is discussed, with emphasis on the author''s ‘formal Darwinism project’. Generally, favourable conclusions are drawn about the validity of assuming fitness maximization, but the need for continuing work is emphasized, along with the possibility that substantive exceptions may be uncovered. The formal Darwinism project aims more ambitiously to represent in a formal mathematical framework the central point of Darwin''s Origin of Species, that the mechanical processes of inheritance and reproduction can give rise to the appearance of design, and it is a fitting ambition in Darwin''s bicentenary year to capture his most profound discovery in the lingua franca of science.     

Darwin without borders? Looking at ‘generalised Darwinism’ through the prism of the ‘hourglass model’

This article critically analyzes the arguments of the ‘generalized Darwinism’ recently proposed for the analysis of social-economical systems. We argue that ‘generalized Darwinism’ is both restrictive and empty. It is restrictive because it excludes alternative (non-selectionist) evolutionary mechanisms such as orthogenesis, saltationism and mutationism without any examination of their suitability for modeling socio-economic processes and ignoring their important roles in the development of contemporary evolutionary theory. It is empty, because it reduces Darwinism to an abstract triple-principle scheme (variation, selection and inheritance) thus ignoring the actual structure of Darwinism as a complex and dynamic theoretical structure inseparable from a very detailed system of theoretical constraints. Arguing against ‘generalised Darwinism’ we present our vision of the history of evolutionary biology with the help of the ‘hourglass model’ reflecting the internal dynamic of competing theories of evolution.     

Darwin’s contributions to genetics

Darwin’s contributions to evolutionary biology are well known, but his contributions to genetics are much less known. His main contribution was the collection of a tremendous amount of genetic data, and an attempt to provide a theoretical framework for its interpretation. Darwin clearly described almost all genetic phenomena of fundamental importance, such as prepotency (Mendelian inheritance), bud variation (mutation), heterosis, reversion (atavism), graft hybridization (Michurinian inheritance), sex-limited inheritance, the direct action of the male element on the female (xenia and telegony), the effect of use and disuse, the inheritance of acquired characters (Lamarckian inheritance), and many other observations pertaining to variation, heredity and development. To explain all these observations, Darwin formulated a developmental theory of heredity — Pangenesis — which not only greatly influenced many subsequent theories, but also is supported by recent evidence.     

Darwin,Veblen and the problem of causality in economics

This article discusses some of the ways in which Darwinism has influenced a small minority of economists. It is argued that Darwinism involves a philosophical as well as a theoretical doctrine. Despite claims to the contrary, the uses of analogies to Darwinian natural selection theory are highly limited in economics. Exceptions include Thorstein Veblen, Richard Nelson, and Sidney Winter. At the philosophical level, one of the key features of Darwinism is its notion of detailed understanding in terms of chains of cause and effect. This issue is discussed in the context of the problem of causality in social theory. At least in Darwinian terms, the prevailing causal dualism--of intentional and mechanical causality--in the social sciences is found wanting. Once again, Veblen was the first economist to understand the implications for economics of Darwinism at this philosophical level. For Veblen, it was related to his notion of 'cumulative causation'. The article concludes with a discussion of the problems and potential of this Veblenian position.