首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
A、A possible explanation for why green turtles nest in certain locations. B、Physical differences among various groups of green t
A、A possible explanation for why green turtles nest in certain locations. B、Physical differences among various groups of green t
admin
2013-04-25
45
问题
I’ve mentioned how DNA have solved many mysteries in biology. And today I want to talk about how it might relate to hypothesis about the travels of the green turtle. Every winter some green turtles make a 2000 km journey from Brazil to Ascension Island in the middle of Atlantic, where they mate and lay eggs. But the question is why do they travel so far to lay their eggs? One researcher hypothesized that there are two parts to the explanation. One is natal homing, the instinct that drives green turtles to always return to the beach where they were hatched. The second part has to do with continental drift, the theory that the positions of earth continents have changed considerably overtime. Brazil and Ascension Island were once much closer together, and continental drift drove them apart. But the turtles kept on going back to the island where they hatched. However another scientist question this explanation on the ground that it would be very unlikely that conditions would allowe generations of turtles over hundreds of millions of years to keep going back to the same nesting ground every single year. So, what is the connection to DNA? Well, there are groups of green turtles that nest in locations other than the Ascension Island. If green turtles always return to the place where they were hatched, then the turtles that have been going to the Ascension Island to nest would’ve been genetically isolated long enough to have DNA that was very different from the green turtles that nest else where. But when scientists examine DNA from these turtles, their DNA wasn’t that different from the DNA of the turtles that go to Ascension Island. Do you have a shock? Well, we still don’t know the answer to the question about why a certain group of turtles go to Ascension Island, but this study was a nice example of the usefulness of DNA analysis to biology.
选项
A、A possible explanation for why green turtles nest in certain locations.
B、Physical differences among various groups of green turtles.
C、Several examples of mating behavior in green turtles.
D、The impact of continental drift on the diet of green turtles.
答案
A
解析
What?does?the?Prof?mainly?discuss?
转载请注明原文地址:https://kaotiyun.com/show/kSyO777K
0
托福(TOEFL)
相关试题推荐
SECTION4Questions31-40Questions31-35Completethenotesbelow.WriteNOMORETHANTHREEWORDSorANUMBERforeachanswer.
Betweenwhattimesistheroadtrafficlightest?Whichdayoftheweekhastheleasttraffic?
SECTION4Questions31-40Questions31-33CompletethefollowingnotesondifferencesyoumightnoticewhenyougohomeusingNO
Completethenotesbelow.WriteONEWORDAND/ORANUMBERforeachanswer.Requirements:GoodliftaccessLargel
Whichattitudeisassociatedwiththefollowingpeopleduringtheconversation?ChooseSIXanswersfromtheboxandwritetheco
Whichattitudeisassociatedwiththefollowingpeopleduringtheconversation?ChooseSIXanswersfromtheboxandwritetheco
conversation/tocommunicate本题有关这位男士学日语的特定需求。录音原文中Iwillneedtobeableto…和I’llputdown提示其后为答案。由于题目要求不超过三个词,因此该空填写名词或者动词短语均可。
A、BylisteningtoherfatherB、ByworkingforanartistC、BytalkingtothestudioartinstructorD、Bytakingseveralartcourse
ArtMuralsWhyistheclassdiscussingthetechnicalrequirementsofmurals?
随机试题
青藤白阳[江苏2019]
简述1958年秋冬至庐山会议前的纠“左”努力。
下列细胞一定表达HLA-Ⅱ类抗原的是
正常肺部叩诊音为
孕后阴道下血,量由少渐多,有血块,妇科检查:宫颈已扩张,子宫与妊娠月份相符。其正确的诊断是孕后阴道下血,量少,时下时止,轻微下腹胀痛,妇科检查:宫颈口未开,子宫大小与停经月份相符。其正确的诊断是
朱砂安神丸的主治病证是()
甲、乙、丙、丁、戊共同组建一有限责任公司,其中甲以货币40万元出资,乙从甲处借款10万元出资,丙以一辆货车评估作价20万元出资,丁以商标权评估作价30万元出资,戊以一项专利权评估作价50万元出资。公司成立后,经查,丙的货车出资时被高估,当时市场价值应当为1
班主任在班级管理中的领导影响力主要表现在()。
王某承包村里的鱼塘,经过精心饲养,收成看好。就在鱼出塘上市之际,王某不幸溺水而死,而其两个儿子都在外地工作,无力照管鱼塘。王某的同村好友李某便主动担负起照管鱼塘的任务,并组织人员将鱼打捞上市出卖,获得收益4万元,其中,应向村里上缴1万元,李某组织人员打捞出
在实时系统中,系统运行的正确性是同其响应时限紧密相关的。根据截止时间约束的软硬属性划分,视频播放系统属于【67】实时系统,自动驾驶系统属于【68】实时系统。
最新回复
(
0
)