拉马克的归来—对达尔文主义的再审视

适应性突变（adaptive mutation）和表观遗传学（epigenetics）的新进展为拉马克主张的＂获得性遗传＂提供了越来越多的证据,暗示它在生物进化中所起的作用可能远比我们之前想象的要大的多。这虽然与新达尔文主义相左,但却在一定程度上符合经典达尔文主义：作为＂自然选择＂的重要补充,＂获得性遗传＂至少应视作一个辅助的机制而纳入＂达尔文框架＂中。这种建立在多元论基础上的进化观正是达尔文留给后人最重要的遗产。     

纪念达尔文诞辰200周年国际学术会议论文集

2009年10月,世界各地的演化生物学领域的科学家们相聚北京,参加主题为“达尔文200·北京”的国际学术会议,共同纪念达尔文诞生200周年和《物种起源》出版150周年。     

贵州湄潭志留纪初期三叶虫动物群及其意义*

志留纪兰多维列世(Llandovery)鲁丹期(Rhuddanian)是奥陶纪末生物大灭绝后的残存期和复苏期。志留纪初期冈瓦纳大陆边缘壳相地层稀少,多数地区为沉积间断或笔石相地层,研究底栖壳相生物残存-复苏期的宏演化普遍缺乏理想材料,而华南上扬子区贵州湄潭地区发育了志留纪早期的壳相地层,即五里坡层(鲁丹阶中部)和牛场组(鲁丹阶上部),为探索这一关键地史时期三叶虫动物群宏演化型式及其背景机制提供了依据。贵州湄潭岩坪剖面和高江剖面的五里坡层和牛场组共发现三叶虫7目11科15属(含亚属)17种(含1新种、3未定种),根据其属级分类单元的时空分布规律,将这些三叶虫识别为5种宏演化类型:即减缩幸存型、扩增幸存型、复活幸存型、新生型和死支漫步型。不同类型的属级分类单元在大灭绝中具有不同的宏演化型式,体现出其应对灾变而采取的不同的生存策略。减缩幸存型和复活幸存型是大灭绝后生态系统复苏和再次辐射的主要源泉,它们的发展在一定程度上影响着整个生态系统的宏演化进程;新生型的出现则标志着大灭绝后环境的实质性改善,三叶虫的全面复苏也随之到来。     

中国濒危兽类保护基因组学和宏基因组学研究进展与展望

揭示濒危兽类的演化历史、濒危机制及适应性演化策略,是保护生物学关注的重大科学问题。近十几年来,高通量测序技术的不断发展以及多学科交叉融合,为揭示濒危物种的演化历史、遗传结构、适应性演化及其与肠道微生物的协同演化的分子机制提供了重要的技术支撑,由此产生了保护基因组学和保护宏基因组学两个分支学科,为野生动物尤其是濒危动物的保护生物学研究提供了新的方向与思路。本文综述了我国在保护基因组学和保护宏基因组学领域取得的重要进展,并展望未来的发展趋势,以期进一步推动我国濒危兽类保护生物学的发展。     

孟德尔现象的思考

距达尔文发表《物种起源》已经过去150多年了,该书早已被翻译成各种语言文字,深受大众欢迎,进化论也已经深入人心。可能大众说不清楚进化的具体细节和机制,说不清古猿进化成人的具体演化阶段,但一般都知道生物是进化而来的,人也是由古猿进化而来的。     

“杭州西湖文化景观”列入《世界遗产名录》有感

2011年6月24日,＂杭州西湖文化景观＂在法国巴黎举行的联合国教科文组织第35届世界遗产委员会会议上顺利通过审议,正式被列入《世界遗产名录》。世界遗产委员会认为,＂杭州西湖文化景观＂     

昆虫嗅觉策略的进化

洛克菲勒大学和东京大学的研究人员发现,昆虫利用快速反应离子通道感知气味,这是一种完全不同于其他生物的嗅觉机制,也是生物进化领域的一大突破。达尔文生物进化树描绘了生物的进化路线,并可推测当代生物多样性的演化历程,而这项关于离子通道进化的结果有可能导致现有进化树的重构。     

适应性演化的分子遗传机制：以高海拔适应为例

自达尔文时代起,解析适应性演化的机制一直是进化生物学和生态学领域研究最重要的科学问题之一。适应性演化通常指在自然选择驱动下,物种为提高适合度而演化出特定的表型。表型的适应表现在形态、生理生化、组织学、行为学等多个层级。随着分子生物学和测序技术的发展,越来越多的研究揭示了适应性复杂性状的遗传基础。研究适应性演化的分子遗传机制有助于理解塑造生物多样性的进化驱动力以及阐明基因型、表型和环境之间的关联关系。目前已有主效基因、超基因、多基因遗传、非编码区调控、重复序列调控、基因渐渗等多种假说可以解释适应性演化的遗传机制。高海拔极端环境的强选择压力极大地促进了物种表型和遗传适应的发生,对多组学数据的剖析为物种适应性演化提供了新的见解。本文对适应性演化的遗传机制、高海拔极端环境适应研究进展以及目前面临的主要挑战进行了综述,并对未来的发展趋势进行了展望,以期为该领域的科研人员提供参考。     

眼上“屋檐”

19世纪中期,基督教在人们思想领域的统治地位发生了动摇。达尔文的进化论横空出世,引起了划时代的思想革命。达尔文明确地提出——人类是由类人猿演化而来的。这一观点一经提出,立刻引起了轩然大波,上帝造人说与进化论辩论不休,基督教与科学的论战进行得如火如荼。     

心脏发育过程中的信号调控机制研究

我国是出生缺陷高发国家,其中先天性心脏病在各类出生缺陷中居于首位,严重地影响我国的人口素质.同样,后天性心脏血管疾病（心血管疾病）也是影响国民健康和社会发展的主要疾病.近年来研究表明,所谓＂后天性＂心脏血管疾病虽然大多不在胚胎期表现出功能异常,但遗传因素在发病过程中也起关键作用,因此,＂后天性＂心血管疾病也有其发育生物学基础.在一些心血管疾病中,胚胎发育基因如ANF和β-MHC的表达说明胚胎发育的某些机制参与了发病过程.由于出生缺陷和心血管疾病的防治是我国公共卫生和社会发展中亟待解决的重大健康问题,了解心血管系统正常发生发育规律和机制及发病机理并在此基础上建立新的防治策略和防治措施是生命科学需要解决的重大基础科学问题.本文主要综述了目前模式动物,特别是小鼠心脏发育过程中的信号传导调控机制的研究现状及进展.     

The proper place of hopeful monsters in evolutionary biology

Hopeful monsters are organisms with a profound mutant phenotype that have the potential to establish a new evolutionary lineage. The Synthetic Theory of evolutionary biology has rejected the evolutionary relevance of hopeful monsters, but could not fully explain the mechanism and mode of macroevolution. On the other hand, several lines of evidence suggest that hopeful monsters played an important role during the origin of key innovations and novel body plans by saltational rather than gradual evolution. Homeotic mutants are identified as an especially promising class of hopeful monsters. Examples for animal and plant lineages that may have originated as hopeful monsters are given. Nevertheless, a brief review of the history of the concept of hopeful monsters reveals that it needs refinements and empirical tests if it is to be a useful addition to evolutionary biology. While evolutionary biology is traditionally zoocentric, hopeful monsters might be more relevant for plant than for animal evolution. Even though during recent years developmental genetics has provided detailed knowledge about how hopeful monsters can originate in the first place, we know almost nothing about their performance in natural populations and thus the ultimate difference between hopeful and hopeless. Studying the fitness of candidate hopeful monsters (suitable mutants with profound phenotype) in natural habitats thus remains a considerable challenge for the future.     

Macromutation and evolution: the fixation of Goldschmidt's macromutations as species and genus traits. Hairlessness mutations in mammals

A brief survey of the development of concepts on the role of macromutations in evolution is given. Contrary to Iu. A. Filipchenko (1926, 1927), who introduced the "micro- and macromutation" terms and believed that regularities of macroevolution could not be reduced to microevolutionary processes, the majority of "synthetists" explained any form of evolution by changes in allele frequencies. From the studies of Drosophila homoeotic mutants R. Goldschmidt (1940) developed the concept of "hopeful monsters" and their role in macroevolution. However, the homoeotic mutants are of drastically reduced viability, which allows the gradualists to reject Goldschmidt's ideas. The distribution of hairlessness mutations (hairless, nude etc.) with the monogenic pattern of inheritance in mammals was studied. Hairless mutants are known in Peromyscus, Mus musculus, Rattus rattus, R. norvegicus, Canis familiaris, Ovis aries. Hairlessness as norm is found in 53 among contemporaneous 1037 mammalian genera. Part of these cases (hairlessness in all Cetacea and Sirenia) may be explained in terms of both macromutations and obligatory gradualism. There is no doubt as to the macromutational origin of hairlessness in the bat Cheiromeles and the rodent Heterocephalus (Bathyergidae); the genera systematically and ecologically close to these have normal pelage. It is quite possible that hairlessness of walrus (Odobenus) has the same origin. The appearance and fixation of single Goldschmidt's macromutation cannot yet be considered as a macroevolutionary process, though the possibility of fixation of a macromutation in nature as a species and genus character contradicts strongly the concept of obligatory gradualism of evolution.     

Saltational evolution: hopeful monsters are here to stay

Since 150 years it is hypothesized now that evolution always proceeds in a countless number of very small steps (Darwin in On the origin of species by means of natural selection or the preservation of favoured races in the struggle of life, Murray, London, 1859), a view termed “gradualism”. Few contemporary biologists will doubt that gradualism reflects the most frequent mode of evolution, but whether it is the only one remains controversial. It has been suggested that in some cases profound (“saltational”) changes may have occurred within one or a few generations of organisms. Organisms with a profound mutant phenotype that have the potential to establish a new evolutionary lineage have been termed “hopeful monsters”. Recently I have reviewed the concept of hopeful monsters in this journal mainly from a historical perspective, and provided some evidence for their past and present existence. Here I provide a brief update on data and discussions supporting the view that hopeful monsters and saltational evolution are valuable biological concepts. I suggest that far from being mutually exclusive scenarios, both gradual and saltational evolution are required to explain the complexity and diversity of life on earth. In my view, gradual changes represent the usual mode of evolution, but are unlikely to be able to explain all key innovations and changes in body plans. Saltational changes involving hopeful monsters are probably very exceptional events, but since they have the potential to establish profound novelties sometimes facilitating adaptive radiations, they are of quite some importance, even if they would occur in any evolutionary lineage less than once in a million years. From that point of view saltational changes are not more bizarre scenarios of evolutionary change than whole genome duplications, endosymbiosis or impacts of meteorites. In conclusion I argue that the complete dismissal of saltational evolution is a major historical error of evolutionary biology tracing back to Darwin that needs to be rectified.     

Examining the Interaction of Acceptance and Understanding: How Does the Relationship Change with a Focus on Macroevolution?

The goal of this research was to illuminate the relationship between students’ acceptance and understanding of macroevolution. Our research questions were: (1) Is there a relationship between knowledge of macroevolution and acceptance of the theory of evolution?; (2) Is there a relationship between the amount of college level biology course work and acceptance of evolutionary theory and knowledge of macroevolution?; and (3) Can college student acceptance of the theory of evolution and knowledge of macroevolution change over the course of a semester? The research participants included 667 students from a first-semester biology course and 74 students from the evolutionary biology course. Data were collected using both the MATE (a measure of the acceptance of evolutionary theory) and the MUM (a measure of understanding of macroevolution). Pre-instruction data were obtained for the introductory biology course, and pre- and post-data were obtained for the evolutionary biology course. Analysis revealed acceptance of evolution (as measured by the MATE) was correlated to understanding of macroevolution, and the number of biology courses was significantly correlated to acceptance and knowledge of macroevolution. Finally, there was a statistically significant change in students’ understanding of macroevolution and acceptance of evolution after the one-semester evolutionary biology course. Significance of these findings is discussed.     

Transgressive Hybrids as Hopeful Monsters

The origin of novelty is a critical subject for evolutionary biologists. Early geneticists speculated about the sudden appearance of new species via special macromutations, epitomized by Goldschmidt’s infamous “hopeful monster”. Although these ideas were easily dismissed by the insights of the Modern Synthesis, a lingering fascination with the possibility of sudden, dramatic change has persisted. Recent work on hybridization and gene exchange suggests an underappreciated mechanism for the sudden appearance of evolutionary novelty that is entirely consistent with the principles of modern population genetics. Genetic recombination in hybrids can produce transgressive phenotypes, “monstrous” phenotypes beyond the range of parental populations. Transgressive phenotypes can be products of epistatic interactions or additive effects of multiple recombined loci. We compare several epistatic and additive models of transgressive segregation in hybrids and find that they are special cases of a general, classic quantitative genetic model. The Dobzhansky-Muller model predicts “hopeless” monsters, sterile and inviable transgressive phenotypes. The Bateson model predicts “hopeful” monsters with fitness greater than either parental population. The complementation model predicts both. Transgressive segregation after hybridization can rapidly produce novel phenotypes by recombining multiple loci simultaneously. Admixed populations will also produce many similar recombinant phenotypes at the same time, increasing the probability that recombinant “hopeful monsters” will establish true-breeding evolutionary lineages. Recombination is not the only (or even most common) process generating evolutionary novelty, but might be the most credible mechanism for sudden appearance of new forms.     

The concept of macroevolution in view of modern data

Macroevolution, or evolution of superspecies taxa is the process of transformation of “organismal” life flows on the Earth during its geological history. In the present study, this process is analyzed with using the system and evolutionarily?ecological approaches. Based on modern paleontological, evolutionary biological, molecular, and genetic data, mostly on vertebrates and hominins, the major factors and patterns of macroevolution and also the role of macroevolution in the biosphere evolution are discussed. The fundamental bases of the concept of macroevolution, the problems of methodology and methods of the study of organismal evolution are considered. It is shown that the processes at the macroevolutionary level agree with the epigenetic theory of evolution.     

R. Goldschmidt and J. Huxley: creative parallelisms

The comparative analysis of scientific heritage of Richard Goldschmidt and Julian Huxley shows convincingly the resemblance of these two scientists' views over the core problems of evolutionary theory, genetics and development biology. They both contributed to developing a triad "genetics--development--evolution". The problem of a relative growth of animals was the central point in both Goldschmidt's and Huxley's works. Huxley developed a formula of the allometric growth (law of constant differential growth) while Goldschmidt was the first to draw up the broad interpretation of the consequences of that phenomenon. Both scientists belonged to initiators of development genetics and used the "non-morganian" genetics in their efforts of solving problems of macroevolution. Goldschmidt tended toward an idea of an important role of macromutation in the process of macroevolution, though Huxley adhered to more moderate views. But at the same time the concept of preadaptive mutations proposed by Huxley was close to Goldschmidt's idea of macromutants. It is shown that both scientists analyzed profoundly the changes in early stages of embryogenesis in respect to macroevolution. It is not likely to be reasonable to oppose firmly Goldschmidt's saltationism to the evolutionary synthesis of Huxley. They developed the larger biological problems in a similar way, and undoubtedly their works in the field helped to enrich the development of the views over genetics and evolution. The open-minded analysis of Goldschmidt's and Huxley's concepts leads to creating modern and up-to-date views over the theory of evolution where seemingly incompatible things go together rather well and supplement each other. Evo-Devo rediscovered Goldshmidt's Biology and Huxley's Synthesis.     

The main postulate of the vertical evolution theory

In the series of previous publications by the author (2000, 2002, 2005), a genetic model explaining the phenomenon of evolutionary progress was presented. In the present paper, this model is described in general terms. The model is based on views on regular changes of ecological potential of organisms on a macroevolutionary time scale. According to these views, macroevolution has its own pattern, which cannot be seen in the microevolutionary process. Hence, the statement of the synthetic theory of evolution that "macroevolution proceeds via microevolution" is incorrect.     

The main postulate of the theory of vertical evolution

In the series of previous publications by the author (2000, 2002, 2005), a genetic model explaining the phenomenon of evolutionary progress was presented. In the present paper, this model is described in general terms. The model is based on views on regular changes of ecological potential of organisms on a macroevolutionary time scale. According to these views, macroevolution has its own pattern, which cannot be seen in the microevolutionary process. Hence, the statement of the synthetic theory of evolution that “macroevolution proceeds via microevolution” is incorrect.