“自然选择学说”教学中应讲清楚的几个问题

自然选择理论是达尔文进化学说的核心,它阐明了生物进化的原因和过程,正确解释了生物的多样性和适应性.这段内容是"生命的起源和生物的进化"一章教学的重点与难点,下面谈谈在教学中应注意的几个问题.一、关子"选择"的函义"选择"这个概念大体上是指去留的意思,即淘汰和保留之意.达尔文在从事生物进化理论的研究工作时,是从研究饲养动物和栽培植物的起源问题入     

生物多样性起源与进化研究进展

生物多样性的起源与进化是生命科学领域最重要的科学问题之一。多组学数据的积累和相关分析技术的发展, 极大地推动了人们对生物多样性起源与进化的理解和研究, 使得阐明生物进化事件发生的过程与机制成为可能。值此《生物多样性》创刊30周年之际, 本文简要回顾生物多样性起源与进化相关研究在近年来取得的重要研究进展, 以期帮助读者了解该研究方向的发展现状。过去10年中, 生物多样性起源与进化相关研究在生命之树重建、生物多样性时空分布格局、物种概念、物种形成与适应性进化以及新性状起源与多样化等方面取得了许多重要进展, 并在此基础上厘清了许多分类单元间的系统发育关系、揭示了生物多样性分布格局的部分历史成因、提出了新的物种概念和物种形成模型、阐明了新性状和新功能发生的部分分子机制。我们认为, 更精准地重建生命之树、深入挖掘基因组数据以及多学科交叉融合将是今后生物多样性研究的主要趋势。     

生物的进化型式

所谓进化型式就是在大的时间尺度(地质时间)上,生物的延续和变化的特征。而这些特征可以在进化树的形态上表现出来。进化树是生物进化在时间和空间上的延续、间断、分枝状态及其改变的速度等特征。因此研究进化型式就是研究进化树的形态。传统描述的进化型式概括起来主要有三种:一种是直道进化,伴随器官与功能的特化,指生物基本上沿一个“确定”的方向     

生物进化论发展史中的重大事件简述

从 19世纪初法国生物学家拉马克首次提出比较完整的进化理论 ,到新综合进化理论形成经历了近 2个世纪 ,这期间有许多杰出的科学家对生物进化理论的发展做出了重大贡献。本文就其中一些重要事件及其影响做一简述。1　 180 9年 ,法国博物学家拉马克 (J.B.Lamark)《动物学哲学》一书出版。历史上第 1次提出了全面的生物进化学说。他着重讨论环境对生物体形态及结构的直接影响和自然规律的统一主张 ,认为生物的进化是从低等到高等的渐进过程 ,是由于用进废退和获得性遗传所致。拉马克的卓越贡献 ,就是最先唤起人们注意生物界的一切改变 ,与非…     

云南抚仙湖鱼类的若干生物学特性及其对湖泊环境的适应

作者于１９８８年１１月至１９８９年１１月逐月取样研究了抚仙湖鱼类的的生物学特性。在此基础上,本文尝试从生物与环境相统一的观点出发,结合湖泊环境的演变历史,进一步探讨了其生物学特性对湖泊环境的适应。研究结果表明,仙湖鱼类具有一系列共同的生物学特性。依其性质可把这些生物学特性区分为原始性状或特化性状。原始性状提示了抚仙湖现生鱼类是源自该湖所属的江河鱼类区系。特化性状则是鱼类在长期的进化过程中适应相同湖     

进化动力新探

许多学者,包括达尔文和杜布赞斯基等人对生物进化的原因颇有研究,伹对进化的动力问题论述甚少。然而,动力是生物进化的一种根本性的原因,是事物发展的内在根据。不搞清楚这个问题,就很难对生物的进化有更深刻的认识。关于生物进化的动力,流行的提法是遗传与变异(或称遗传与适应)之间的相互作用构成了生物进化的动力,它推动生物的进化,决定生物发展的方向和速度。其中,遗传是一种稳定性的因素,被认为是进化过程中保存物种的方面。由于生物有遗传性,谷子才成其为谷子,鸡才成其为鸡,人才成其为人。但是只遗传还不行,只遗传,原来有多少种生物,就永远是这么多生     

分子进化的概念、理论和方法

严格地说,“分子进化”有两层含意。一层含意是 指生命起源时期的化学进化,即有机分子由简单向复 杂的演变〔们;另一层含意是指生物进化过程中,构成生 物体的大分子,如蛋白质、核酸的演变。由于分子生物 学研究的迅速进展,已经搞清了许多生物大分子的一 级结构。从某些同源蛋白质（或核酸）的比较中,人们发 现,不同生物之间,同源蛋白质（或核酸）结构上的差异 各不相同,亲缘关系近的差异较小,反之则差异较大, 即这些生物大分子象生物的表型一样,能反映物种间 的亲缘关系,体现物种的演化过程。现在,当提及分子 进化时,一般都是指后一层意思。     

病毒体内的遗传物质DNA或RNA，有的呈单链有的呈环链，单链和环链在进化地位上有何意义？

在生物起源过程中,推测最先出现的遗传物质载体是RNA。从化学结构上看,DNA比RNA稳定,双链又比单链稳定。这可能是为什么细胞生物在长期的进化历程中,最终选择了双链DNA作为遗传载体的原因。人们可以通过对进化过程中序列保守的DNA片段进行比对和分析,来了解不同物种在生物进化中的相互关系。     

基于生物适应进化原理论证生物进化的动力

文章从现有主流生物进化理论存在的问题入手, 以生物适应进化原理为认识基础, 讨论生物进化的动力, 以求对生物进化机制有一个新的认识。在薛定谔“生命赖负熵生存”观点的指导下, 提出了“负熵流”包括能量流、物质流和信息流, 以及负熵流是生命生存和发育的动力的观点。作者在原有生物适应进化原理基础上, 修改完善并提出了“DNA、RNA和蛋白质在环境作用下的生物适应进化调控系统”理论, 并根据系统发育是个体发育的“积分”的观点, 推论得出生物与环境的负熵差引起的负熵流也是生命进化的动力, 对生物进化机制作出了新的理解。基于这样的生物进化机制的认识, 提出了“进化是一个子系统在其上一等级系统中, 将自身全部或部分信息遗传给下一代子系统, 并在其适应上一等级系统过程中, 产生一些新质, 终止一些旧质, 从而在其上一等级系统中得以延续的变化过程”的概念, 并探讨了一些与进化有关的其他争议问题。     

生物进化的"溶源菌"关系演变进程

从免疫学角度分析了病毒与噬菌体建立的“溶源菌”关系．提出了生物进化中的“溶源菌”进程观点,对一些生物进化问题做出了新的解释,包括生物在进化历程中如何抵抗疾病危害、保存物种并繁衍后代,寒武纪大爆发,生物进化在一定范围内出现的不连续性,生物间基因组的“C值悖理”及“重复基因序列”的由来等。结合转基因技术的成熟运用,提出了新的生物进化关系式:B=A x．有利于进化理论的深化完善。     

Using Avida-ED for Teaching and Learning About Evolution in Undergraduate Introductory Biology Courses

Evolution is a complex subject that requires knowledge of basic biological concepts and the ability to connect them across multiple scales of time, space, and biological organization. Avida-ED is a digital evolution educational software environment designed for teaching and learning about evolution and the nature of science in undergraduate biology courses. This study describes our backward design approach to developing an instructional activity using Avida-ED for teaching and learning about evolution in a large-enrollment introductory biology course. Using multiple assessment instruments, we measured student knowledge and understanding of key principles of natural selection before and after instruction on evolution (including the Avida-ED activity). Assessment analysis revealed significant post-instruction learning gains, although certain evolutionary principles (most notably those including genetics concepts, such as the genetic origin of variation) remained particularly difficult for students, even after instruction. Students, however, demonstrated a good grasp of the genetic component of the evolutionary process in the context of a problem on Avida-ED. We propose that: (a) deep understanding of evolution requires complex systems thinking skills, such as connecting concepts across multiple levels of biological organization, and (b) well designed use of Avida-ED holds the potential to help learners build a meaningful and transferable understanding of the evolutionary process. An erratum to this article can be found at     

A 21st century view of evolution: genome system architecture, repetitive DNA, and natural genetic engineering

The last 50 years of molecular genetics have produced an abundance of new discoveries and data that make it useful to revisit some basic concepts and assumptions in our thinking about genomes and evolution. Chief among these observations are the complex modularity of genome organization, the biological ubiquity of mobile and repetitive DNA sequences, and the fundamental importance of DNA rearrangements in the evolution of sequenced genomes. This review will take a broad overview of these developments and suggest some new ways of thinking about genomes as sophisticated informatic storage systems and about evolution as a systems engineering process.     

University Evolution Education: The Effect of Evolution Instruction on Biology Majors�� Content Knowledge, Attitude Toward Evolution, and Theistic Position

Issues regarding understanding of evolution and resistance to evolution education in the United States are of key importance to biology educators at all levels. While research has measured student views toward evolution at single points in time, few studies have been published investigating whether views of college seniors are any different than first-year students in the same degree program. Additionally, students choosing to major in biological sciences have largely been overlooked, as if their acceptance of evolution is assumed. This study investigated the understanding of evolution and attitude toward evolution held by students majoring in biological science during their first and fourth years in a public research university. Participants included students in a first-year introductory biology course intended for biological science majors and graduating seniors earning degrees in either biology or genetics. The portion of the survey reported here consisted of quantitative measures of students’ understanding of core concepts of evolution and their attitude toward evolution. The results indicate that students’ understanding of particular evolutionary concepts is significantly higher among seniors, but their attitude toward evolution is only slightly improved compared to their first-year student peers. When comparing first-year students and seniors, students’ theistic position was not significantly different.     

How are humans related to other primates? A guided inquiry laboratory for undergraduate students

Understanding that phylogenies depict the evolutionary history of species is a critical concept for undergraduate biology students. We present an inquiry-based laboratory exercise exploring this concept in the context of the human phylogeny. This activity reinforces several important biological concepts and skills. Bolstered concepts include that evolution is descent with modification, that evolution is a genetic process, and that humans are closely related to apes. In terms of thinking skills, the lab gives students practice with hypothetical-deductive thinking, quantifying patterns from complex data, and evaluating evidence.     

Reliability of regulatory networks and its evolution

The problem of reliability of the dynamics in biological regulatory networks is studied in the framework of a generalized Boolean network model with continuous timing and noise. Using well-known artificial genetic networks such as the repressilator, we discuss concepts of reliability of rhythmic attractors. In a simple evolution process we investigate how overall network structure affects the reliability of the dynamics. In the course of the evolution, networks are selected for reliable dynamics. We find that most networks can be easily evolved towards reliable functioning while preserving the original function.     

Not Looking a Gift Horse in the Mouth: Exploring the Merits of a Student–Teacher–Scientist Partnership

One major emphasis of reform initiatives in science education is the importance of extended inquiry experiences for students through authentic collaborations with scientists. As such, unique partnerships have started to emerge between science and education in an ongoing effort to capture the interest and imaginations of students as they make sense of the world around them. One such partnership is called the student–teacher–scientist partnership, in which teachers and their students participate in and contribute to the research of scientists. This article explores a partnership between a 10th-grade biology teacher, her students, and practicing scientists who collaborated in the design, implementation and evaluation of a horse evolution unit. The primary goal of the collaborative activity was to involve teachers and students in a process of conceptual change as a means of eliminating common misconceptions implicit in horse evolution displays in museums in various parts of the country. The evidence-based lessons developed enhanced students’ understanding of concepts in macroevolution but also connected the science classroom with a community of scientists whose personalization of the horse evolution unit situated biological concepts and the learning experience within the context of real-world issues.     

Preservice Teacher Understanding and Vision of how to Teach Biological Evolution

The learning and teaching of biological evolution is conceptually challenging. To fully comprehend evolution, it is posited that individuals also need to understand the roles that the nature of science and situations of chance play in the process. The consistent detection of misconceptions of evolution suggests that new approaches to increasing understanding need to be explored. I predicted that preservice teachers’ ideas for teaching biological evolution could be influenced by three brief web-based interventions, one focused on the common misconceptions of evolution, one on the nature of science, and one on situations of uncertainty in the context of evolution. An experimental group received a combination of the three web-based tutorials while a control group received the misconceptions and nature of science instruction and a time on task filler tutorial. Participants were directed to develop a lesson idea applying the knowledge they learned from the tutorials. The lesson ideas were examined for evidence of the influence of the web-based instruction, participant understanding and misconceptions of concepts, and their ideas about teaching evolution. The results of this study revealed that the participating preservice teachers held a wide range of conception and misconception of evolution, were somewhat influenced by the tutorials, and had an array of visions for teaching evolution. The outcomes support the need for further investigation into the multifaceted nature of preparing preservice teachers to teach evolution.     

The notion of homology in current comparative biology

Current notions on homology, and its recognition, causation, and explanation are reviewed in this report. The focus is primarily on concepts because the formulation of precise definitions of homology has contributed little to our understanding of the issue. Different aspects or concepts of homology have been contrasted, currently the most important ones being the distinction between systematic and biological concepts. The systematic concept of homology focuses on common ancestry and on taxa; the biological concept tries to explain patterns of conservatism in evolution by shared developmental constraints. Similarity or correspondence is generally accepted as a primary criterion in the delimitation of homologues, albeit that this criterion is not without practical and theoretical problems. Apart from similarity, the biological concept of homology also stresses developmental individuality of putative homologous structures. Structural and positional aspects of homology can be separated, with positional homology acquiring an independent status. Similarity, topographic relationships, and ontogenetic development cannot be tests of homology. Within the cladistic paradigm, the most decisive test of homology is that of congruence; proponents of the biological-homology concept have been less concerned with test implications. Adopting a hierarchical view of nature suggests that characters have to be homologized at their appropriate level of organization. A taxic or systematic approach to homology has precedence over a transformational or biological approach. Nevertheless, pattern analysis and process explanations are not independent of each other.