面向世界科技前沿,面向国家重大需求,面向国民经济主战场,率先实现科学技术跨越发展,率先建成国家创新人才高地,率先建成国家高水平科技智库,率先建设国际一流科研机构。

——中国科学院办院方针

首页 >  > 

彩神IV争霸-APP下载

時間:2022-08-15 來源:本站 點擊:258次
【字体:

物种迅速进化很有可能没啥用,反倒促使他们更早灭绝******

大家一般觉得,在生物多元性的进化全过程中,很多大的进化支系是根据更快的进化发生的,他们有着更好的生物多元性;而较小的支系则经历了更迟缓的进化,他们的生物多元性更低。殊不知一项新的研究发现:进化得越来越快,绝种得也越来越快。

Rapidly evolving species more likely to go extinct, study suggests。

Researchers at the University of Bristol have found that fast evolution can lead to nowhere.。

美国布里斯托高校的科学研究工作人员最新发现,物种迅速进化很有可能促进他们更早绝种。

In a new study of lizards and their relatives, Dr Jorge Herrera-Flores of Bristol's School of Earth Sciences and colleagues have discovered that 'slow and steady wins the race'.。

布里斯托高校地球上研究院的Jorge Herrera-Flores博士以及朋友,在一项对于蛇蜥以及血亲物种的分析中发觉,“迟缓而平稳”的进化方式,使他们获得了地球上物种“进化比赛”。

The team studied lizards, snakes and their relatives, a group called the Lepidosauria. Today there are more than 10,000 species of lepidosaurs, and much of their recent success is a result of fast evolution in favourable circumstances. But this was not always the case.。

该学习工作组的研究对象是有鳞亚纲物种,包含:蛇蜥,蛇和别的血亲物种。现如今地球上有鳞亚纲物种总数做到1万多种,大家觉得该类群的取得成功进化非常大水平上是在有益地理环境下迅速进化产生的,但状况并不是一直这般。

Mr Herrera-Flores explained: "Lepidosaurs originated 250 million years ago in the early Mesozoic Era, and they split into two major groups, the squamates on the one hand, leading to modern lizards and snakes, and the rhynchocephalians on the other, represented today by a single species, the tuatara of New Zealand. We expected to find slow evolution in rhynchocephalians, and fast evolution in squamates. But we found the opposite."。

Herrera-Flores博士表述说:“有鳞亚纲物种始于2.5亿光年前三叠纪初期,他们分成两大支系,一支是有鳞类生物,慢慢演化进化成当代蛇蜥和蛇,另一支是喙头目生物,现如今仅存有单一物种——新加坡大蜥蜴。一般我们觉得喙头目生物是迟缓进化而致,有鳞类生物理应发生了迅速进化,但事实上,回答恰好反过来。”。

"We looked at the rate of change in body size among these early reptiles," said Dr Tom Stubbs, a collaborator. "We found that some groups of squamates evolved fast in the Mesozoic, especially those with specialised lifestyles like the marine mosasaurs. But rhynchocephalians were much more consistently fast-evolving."。

此项科学研究的合作方Tom Stubbs 博士说:“在科学研究了这种初期脊椎动物的身型转变速率,发觉一些有鳞类生物在三叠纪阶段进化速率迅速,尤其是这些拥有独特生活习惯的非常巨怪,比如:日常生活在深海中的沧龙。但意想不到的是,喙头目生物持续保持迅速的进化速率。”。

图中是侏罗纪晚期的蛇颈龙,它们生活在大约1.5亿年前,骨骼化石挖掘于德国南部,它是一种非凡的长体游泳喙头目生物。  图上是侏罗纪时代末期的蛇颈龙,他们生话在大概1.5亿光年前,人体骨骼动物化石发掘于法国南边,它是一种不凡的长体游水喙头目生物。

"In fact, their average rates of evolution were significantly faster than those for squamates, about twice the background rate of evolution, and we really did not expect this," said Dr Armin Elsler, another collaborator. "In the later part of the Mesozoic all the modern groups of lizards and snakes originated and began to diversify, living side-by-side with the dinosaurs, but probably not engaging with them ecologically. These early lizards were feeding on bugs, worms, and plants, but they were mainly quite small."。

“实际上,喙头目生物的均值进化速率明显超出有鳞类生物,大概是后面一种进化速率的二倍,这也是先前沒有想到的。”该科学研究的另一位合作方Armin Elsler博士说,“在三叠纪中后期,全部当代蛇蜥和蛇种都出現了,并逐渐房屋朝向多元化发展趋势,他们与霸王龙物种日常生活在一起,但很有可能在绿色生态上不容易与霸王龙产生触碰。这种远古蜥蜴以小虫子,蜘蛛和绿色植物为食,他们的身型都并不大。”。

Prof Mike Benton added: "'After the extinction of the dinosaurs, 66 million years ago, at the end of the Mesozoic, the rhynchocephalians and squamates suffered a lot, but the squamates bounced back. But for most of the Mesozoic, the rhynchocephalians were the innovators and the fast evolvers. They tailed off quite severely well before the end of the Mesozoic, and the whole dynamic changed after that."。

Mike Benton 专家教授填补道:“6600百万年三叠纪后期,恐龙的灭绝以后喙头目生物和有鳞类生物遭到了非常大严厉打击,但有鳞类生物物种迅速反跳。但就三叠纪大部分物种来讲,喙头目生物是进化颠覆性创新,处在较迅速进化情况,但在三叠纪后期该种群数量就快速走入没落,在哪以后,全部动态性就发生了转变。”。

This work confirms a challenging proposal made by the famous palaeontologist George Gaylord Simpson in his 1944 book Tempo and Mode in Evolution. He looked at the fundamental patterns of evolution in a framework of Darwinian evolution and observed that many fast-evolving species belonged to unstable groups, which were potentially adapting to rapidly changing environments.。

此项全新科学研究证明了知名的古生物学者乔冶·盖洛德·辛普森在1944年出版发行的《进化的节奏感和方式》一书里明确提出的趣味性提议。他在爱因斯坦进化论的理论框架下科学研究了物种进化的基本原则,并了解到很多迅速进化的物种归属于不稳定人群,他们能够融入迅速改变的地理环境。

蜥蜴和蛇的进化速度(蓝线)在大约2亿年的时间里远低于喙头目生物(绿线),而且它们只是在最近5000万年左右才发生了逆转。  蛇蜥和蛇的进化速率(绿线)在大概2年前的時间里远小于喙头目生物(蓝线),并且他们仅仅在近期5000萬年上下才发生了反转。

Prof Benton continued: "Slow and steady wins the race. In the classic Aesop's fable, the speedy hare loses the race, whereas the slow-moving tortoise crosses the finishing line first. Since the days of Darwin, biologists have debated whether evolution is more like the hare or the tortoise. Is it the case that big groups of many species are the result of fast evolution over a short time or slow evolution over a long time?

Benton专家教授再次讲到:“脚踏实地才可以赢得比赛。在传统的寓言故事中,跑的快的小兔子最后却输掉赛事,而跑得慢的小乌龟第一个冲过去了终点。从爱因斯坦时期逐渐,生物学者们就一直在争执最好物种进化更像小兔子或是小乌龟。有着多物种支系的物种是短期内内迅速进化的結果,或是长期迟缓进化的結果?”。

"In some cases, they can stabilise and survive well, but in many cases the species go extinct as fast as new ones emerge, and they can go extinct, just like the napping hare. On the other hand, Simpson predicted that slowly evolving species might also be slow to go extinct, and could in the end be successful in the longer term, just like the slow-moving but persistent tortoise in the fable."。

“在某种状况下,很多物种能平稳地进化发展趋势,非常好地存活出来。但在大部分状况下,物种绝种速率和新物种创造速率基本上是一样快,如同小兔子打盹的時间那麼“短暂性”。辛普森曾推测称,进化迟缓的物种很有可能也会迟缓地迈向绝种,并可以在很长一段时间内比迅速进化的物种更加取得成功,如同寓意故事中迟缓挪动但锲而不舍的小乌龟一样。”。

2月21日起 西安市艾滋病自愿咨询门诊恢复服务******

  当前新型冠状病毒疫情防控已进入常态化,西安市疾控中心将于2月21日起恢复艾滋病自愿咨询门诊个人咨询检测业务。

  为进一步巩固疫情防控工作,防止人员聚集,保障大家的生命安全和身体健康,该中心艾滋病自愿咨询门诊实行线上预约线下检测模式。

  公众可通过关注“西安疾病控制”微信公众号,依次进入“在线服务”-“艾滋病检测预约”模块进行预约登记,预约成功后按照预约时间在中心门卫室出示“西安市个人电子码”和“系统预约成功短信”、测量体温、持本人身份证登记后进入108室进行咨询检测,咨询检测期间请全程佩戴口罩,做好个人防护。如有疑问,可电话咨029-85525625。

  此外,将于2月21日起恢复艾滋病确证实验室收样时间,具体为每周三和周四。请各机构送样人员严格按照生物安全要求运送样本,做好个人防护,领取报告时务必携带工作证明。

  华商报记者 李琳



来源:华商网-华商报

编辑:方正

【彩神IV争霸-APP下载👉👉十年信誉大平台,点击进入👉👉 打造国内最专业最具信赖的彩票平台,为您提供彩神IV争霸-APP下载用户登录全网最精准计划软件,APP下载登陆,强大的竞彩网上推荐!!】

Liverpool cruise past Southanmpton in English Premier League******

LONDON, Nov. 27 (Xinhua) -- Liverpool kept the pressure on leaders Chelsea in the English Premier League with a 4-0 win against Southampton at home on Saturday.。

Diogo Jota scored twice for Jurgen Klopp's side in the 32nd and 97th minute apiece. Thiago Alcantara and Virgil van Djik also found the net for the home team.。

The Reds now sit one point behind Chelsea, who host Manchester United on Sunday.。

Steven Gerrard's winning start in the Premier League continued as Aston Villa won 2-1 away to Crystal Palace to make it two wins from two games since he joined from Glasgow Rangers.。

Matt Targett put Villa ahead in the 15th minute following a corner and John McGinn's first time shot five minutes from time assured the win even though Marc Guehi scored a late consolation goal for the home side.。

Arsenal returned to winning ways after last weekend's 4-0 defeat to Liverpool with a 2-0 win at home to Newcastle United leaving the visitors without a win in their first 13 games of the season.。

Newcastle coach Eddie Howe was able to sit in the dugout for the first time after recovering from the COVID-19 and saw how second half goals from Bakary Saka and Gabriel Martinelli condemned his side to defeat.。

Meanwhile, Norwich City picked up another point to extend their unbeaten run to three games with a 0-0 draw at home to Wolves. Norwich will be disappointed to not pick up all three points after Wolves keeper Jose Sa denied both Teemu Pukki and Lukas Rupp with late saves.。

In Saturday's last game, Brighton and Leeds United drew 0-0 in a result that extended Brighton's winless run to eight games. Brighton had most of the chances, but familiar failings in front of goal cost them the chance of a win. Enditem。

Guangzhou coach Guo banned five matches for interrupting CBA game in disagreement******

BEIJING, Nov. 1 (Xinhua) -- The Chinese Basketball Association (CBA) has slapped Guangzhou Loong Lions head coach Guo Shiqiang with a five-game suspension after his controversial behavior led to an interruption of a CBA game on Sunday.。

Guangzhou trailed the Jilin Northeast Tigers at 94-93 with 8.5 seconds to play, when Zhu Mingzhen was whistled his sixth personal foul, giving Jilin's Cui Jinming a pair of free throws.。

But thinking that Jilin's Dai Huaibo should have been given traveling violation before the foul took place, Guo blamed the referees, also refusing to make substitutions as ruled. He fielded another player onto the court around five minutes later.。

In Monday's announcement, the league's ruling body said that Guo's behavior was a severe disturbance toward the game, thus banning Guo five matches and fining him 20,000 RMB (3,126 US dollars).。

After the game resumed, Cui missed both free throws. Chen Yingjun made a driving layup with 1.8 seconds remaining and helped Guangzhou escape with a 95-94 victory in a dramatic finish.。

Guangzhou sits fifth among 20 outfits with a win-loss record of 5-2. Enditem。

原中央委员被公诉,是十九大以来首个被指控这一罪名的“老虎”

1.俄媒:乌克兰前总统波罗申科出现在波兰华沙机场

2.海军护卫舰支队南海多课目射击训练

3.70多家百亿私募还在亏,这类私募却大赚

4.冲绳海岸现不明漂浮物?或暴露美航母新动向

© 1996 - 彩神IV争霸-APP下载 版权所有 xxxxx

地址:

电话:(总机)

编辑部邮箱:

趣购彩票-购彩中心-9号彩票-官网-好彩票-【购彩大厅】-一分快3-首页_欢迎您-手机快三app下载-首页-购彩平台-首页-通盈彩票-【购彩大厅】-恒彩彩票-首页-彩票双胆独-官网-网购彩票-官网-澳门金沙.官方正网-彩神app2_彩神app2官方下载-彩神国际官网-彩神国际首页-彩友会-官网-神彩争霸app官方_首页-彩神2 - 彩神2官方投注app平台|注册
王楠女儿上新闻联播 6岁笑笑打球好帅有望进国家队| 吉尔吉斯斯坦总统:俄方不再反对,商讨20多年的中吉乌铁路计划明年开工| 马斯克人生中最尴尬的20秒 被问如何看待中美关系| 禁止驶入,北部湾北部水域进行实弹射击| 行驶中起火!186万保时捷被烧成空壳,4S店紧急回应| 加拿大空军“雪鸟”飞行队发生事故 涉事机型停飞| 离婚不抢车不抢房,他们竟然抢狗!离谱!| 未能按时付息或诱发交叉违约 惠誉下调弘阳地产评级至C| 西藏通报感染人数为何大幅增加?主要有三方面原因| 巴黎戴高乐机场一男子持刀袭警被击毙| 上了年纪后忙着变美 才能忘记变老| 顶流出手!邓晓峰、冯柳大举加仓 买的还是"旧爱"| 邮报:尽管多家球队希望租借范登贝尔赫,利物浦还是想将其留下| 空间站建造阶段后续飞行任务标识发布| 王子文谈8岁儿子,大方分享喜欢吴永恩的原因| 美军B-1B轰炸机在机库里接受维修| 土耳其议会批准将派驻利比亚的土军驻扎期限延长18个月| 俄军接装新型无人直升机 将用于研究反无人机作战|