Social transmission of courtship behavior and mating preferences in brown-headed cowbirds,<Emphasis Type="Italic">Molothrus ater</Emphasis>

Studies of the social learning of courtship behaviors and mating preferences of brown-headed cowbirds (Molothrus ater) are reviewed. Earlier work has suggested that cowbirds from behaviorally distinct populations mate preferentially with others from the same population. Studies are described which indicate that patterns of courtship behavior that differ by population can be socially transmitted across generations are described. Social background affects male songs, female preferences for males as mates, and courtship interactions between females and males. Thus, social traditions influence mating decisions and may, ultimately, impact reproductive success in this species. Recent work on possible social mechanisms involved in the ontogeny of courtship behavior is described. The implications of these findings are discussed, and future research directions are suggested.     

前哨站

新年新气象!女巫迪迪在这里给淀粉们拜年喽!祝大家猪年旺旺!这一期是《少电》创刊10周年特刊,也是2007年《少电》改版后的第一期!游戏栏目“游间道”经过策划,也做了一番新调整。除了继续为大家刊登精彩游戏的详细攻略,“前哨站”会不定期向大家介绍适合青少年的绿色健康网络游戏。另外又开辟了一个新拦目——“我在网湖飘”,顾名思义,就是关于网络游戏的拦目啦!由于《梦幻西游》是很多淀粉都爱玩的游戏,所以第一期“我在网湖飘”,就和大家讲讲《梦幻西游》里的事儿吧!亚亚的“电淘铺”经过几个月的试营业,已经步入正轨。迪迪计划以后推出的游戏攻略,其产品都可以在“电淘铺”里邮购,这样淀粉们就可以一边看攻略,一边玩游戏了。也不用因为没有游戏玩,只好可怜巴巴地把攻略当故事读了。《新绝代双骄前传》攻略已经全部刊登,而亚老板的“电淘铺”同时也在出售正版游戏,大家不要错过机会哦!另外,迪迪计划做一个“游戏风云榜”。哈哈,没错啦,虽然名字俗了点,但是大家一看就明白是什么意思了嘛!“游戏风云榜”每一期都会更新,大家可以将电子邮件发送到我信箱(nw_dd@126．com)回答以下问题。每一期都会抽选“热心评榜员”,抽中有奖哦!现在在玩的一款单机游戏现在在玩的一款网络游戏你最喜欢的单机游戏你最喜欢的网络游戏     

前哨站

经过一段时间的休整,迪迪从每根骨头到每根汗毛都往外冒懒气。当第九期的发稿期又来临时,大家都热火朝天地编着稿子,身为责任编辑的我却假装“无所事事”。虽然自己没什么动力编稿,但第一次做责编,对催稿的兴趣还是很大的,早就想趁机好好“吆喝”一通了。可没想到,我还没开始催,西西、侠客、鱼小朵、嘟嘟就纷纷及时交稿了。倒剩下了这个“要债”的迪迪是最后一名!那可不行,我这个责编总不能是最后吧?想到了远在外地学习的暴暴蓝,我又偷偷乐了。听说暴暴蓝现在又忙又累,肯定没我交得快!到时候我再跟他催稿,行使一下我的“权利”!HOHO……但是仅仅过了一天,暴暴蓝就把他熬了一个通宵编好的稿     

A window into different cultural worlds: young children's everyday activities in the United States, Brazil, and Kenya

A powerful means to understand young children's normative development in context is to examine their everyday activities. The daily activities of 79 children (3 years old) were observed, for 20 hr each, in their usual settings. Children were selected from 4 cultural groups: European American and African American (Greensboro, United States), Luo (Kisumu, Kenya), and European descent (Porto Alegre, Brazil), evenly divided by social class. Examining children's naturally occurring engagement in school-relevant activities, both in and out of child care, revealed the importance of ecological context. The variation in activities was not explainable simply by cultural group (including race within the United States) or social class, but by the intersection of culture and class. The developmental implications of these findings are discussed.     

Studying human disease genes in Caenorhabditis elegans: a molecular genetics laboratory project

Scientists routinely integrate information from various channels to explore topics under study. We designed a 4-wk undergraduate laboratory module that used a multifaceted approach to study a question in molecular genetics. Specifically, students investigated whether Caenorhabditis elegans can be a useful model system for studying genes associated with human disease. In a large-enrollment, sophomore-level laboratory course, groups of three to four students were assigned a gene associated with either breast cancer (brc-1), Wilson disease (cua-1), ovarian dysgenesis (fshr-1), or colon cancer (mlh-1). Students compared observable phenotypes of wild-type C. elegans and C. elegans with a homozygous deletion in the assigned gene. They confirmed the genetic deletion with nested polymerase chain reaction and performed a bioinformatics analysis to predict how the deletion would affect the encoded mRNA and protein. Students also performed RNA interference (RNAi) against their assigned gene and evaluated whether RNAi caused a phenotype similar to that of the genetic deletion. As a capstone activity, students prepared scientific posters in which they presented their data, evaluated whether C. elegans was a useful model system for studying their assigned genes, and proposed future directions. Assessment showed gains in understanding genotype versus phenotype, RNAi, common bioinformatics tools, and the utility of model organisms.     

Are Africans,Europeans, and Asians Different “Races”? A Guided-Inquiry Lab for Introducing Undergraduate Students to Genetic Diversity and Preparing Them to Study Natural Selection

Many students do not recognize that individual organisms within populations vary, and this may make it difficult for them to recognize the essential role variation plays in natural selection. Also, many students have weak scientific reasoning skills, and this makes it difficult for them to recognize misconceptions they might have. This paper describes a 2-h laboratory for college students that introduces them to genetic diversity and gives them practice using hypothetico-deductive reasoning. In brief, the lab presents students with DNA sequences from Africans, Europeans, and Asians, and asks students to determine whether people from each continent qualify as distinct "races." Comparison of the DNA sequences shows that people on each continent are not more similar to one another than to people on other continents, and therefore do not qualify as distinct races. Ninety-four percent of our students reported that the laboratory was interesting, and 79% reported that it was a valuable learning experience. We developed and used a survey to measure the extent to which students recognized variation and its significance within populations and showed that the lab increased student awareness of variation. We also showed that the lab improved the ability of students to construct hypothetico-deductive arguments.     

读者来信

我国农村，特别是偏远落后地区，社会文化和经济现状与城市有着显著距离：而由于教材和教育的“参照点”又多以城市为中心，使得经济落后、办学条件较差的农村孩子在接受知识方面有困难，无法顺利通过升学考试，实现挤进城市的梦想。与其考不上大学，不如辍学回家，这就当然成为“读书无用”的理论根源。