http://www.ostrich.org.tw/html/front/bin/ptdetail.phtml?Part=ind009&Category=286065
從噗浪裡得知雁鴨與鴕鳥也有陰莖
查估狗大神發現
台灣區人工飼養鴕鳥協會
有不錯的資訊
引用如下
鴕鳥交配行為
一、求偶
（一）母鳥：
母鳥面對發情對象時會有直立、排尿、排糞和其他動作出現，並以發嘶聲、啄、踢等動作驅趕其他母鳥，或其他不想要的雄鳥。
（二）公鳥：
公鳥的求偶行為通常稍晚些，當求愛開始時會表現出極大的敵意，將翅膀高舉，尾豎起，以此姿勢加上發出嘶聲，向其他公鳥或其他動物威嚇，有時也以此姿勢追趕所選擇的母鴕鳥。
當公母配對後，在野外牠們會選擇一遠離大群體的地方，繼續求偶行為，並有同步的活動，而公鳥會兩翼左右搖擺，圍繞在母鳥身旁狂跳〝華爾滋舞〞（求偶舞），有時母鳥會一起跳。
二、交配
（一）時間：交配多在上午6～9時或下午14～16時進行。
（二）交配前：
1、公鳥：以半伏臥式抖動雙翅，折曲長頸至背部，持續長時間不停地用頭左右的擊背有聲
2、母鳥：接受的母鳥，即會臥於附近地面，半展雙翅不斷的揮動，頭頸向前方伸展，
（三）交配：
此時雄鳥會快步走向雌鳥，雙腳踏步有聲，很快雙足蹬於雌鳥背部，伏在雌鳥背部及腰部，雄鳥的尾部伸向雌鳥尾下，兩鴕鳥的泄殖孔緊貼，雄鳥陰莖深入雌鳥的泄殖孔內進行交配，此時雄鳥抖動雙翅，頸部伸直並膨脹，不停擺動頭頸，同時發出〝咕咕〞粗啞聲。雌鳥接受交配後，頭頸向正前方伸展，略有擺動和發出輕微的嘶啞之聲，交配時間一般約為35～40秒，
（四）交配後：
1、公鳥：交配後立即離去，桃紅色陰莖仍垂於體側，稍待片刻後才收回，雄鳥1天平均交配3~5次。
2、母鳥：則臥於原地不動，約1～2分鐘後才離去。
鴕鳥的繁殖生態
一、繁殖壽命
野生鴕鳥平均壽命為30～40歲，人工飼養者略長壽些，可達50～60歲，繁殖年齡約為20～25年，甚至有到42歲。
二、性成熟
公鳥約於25～36月齡達性成熟後每刺進入繁殖季節時，其腳脛及會喙呈紅色；母鳥較早熟，約20～24月齡可開始產蛋。
三、夫妻制
野生鴕鳥雖有一夫一妻制，但通常以一夫多妻制為主，多為1公2母。
四、築巢
築巢的工作主要由公鳥承擔，偶爾母鳥也會參與該項工作，鴕鳥喜歡在沙地築巢，公鳥會在母鳥開始產蛋前就在巢的附近警衛，對巢穴的安全非常警覺，故在繁殖季節公鳥會變得較具攻擊性，母鳥在產蛋期也可能較具攻擊性，但大部分時候是嫻靜、馴良的。
五、產蛋
在野生狀態下，一窩蛋通常在2週內產完，主要和次要母鳥是該窩蛋的主要生產者，排在第3位的則貢獻不大，且最有可能離開該公鳥而與其它公鳥交配。
六、產蛋數
野生母鴕鳥每隻每次產蛋約8～15個，因每窩有多隻母鳥產蛋，所以每窩約20～15個，年產蛋約30～40顆；在馴養的狀態下，因產蛋後就被取走，產蛋數較多，一般年平均產蛋數為60～100顆。
七、蛋孵化
孵化期平均為42天，自然孵化時，公母鳥輪流孵化，白天母鴕鳥孵，晚上公鳥孵。鴕鳥對孵蛋的保護意識很強，孵蛋時經常將頭頸放在地上，此乃預防被發現，但此時極具攻擊性，雖受強大的攻擊，也會進行反抗保護蛋。
八、育雛
野外由公鳥負責
2010年10月5日 星期二
試管嬰兒之父 摘2010諾貝爾醫學獎
試管嬰兒之父 摘諾貝爾醫學獎一度受宗教界與輿論批判 卻造福400萬試管嬰兒2010年10月05日
http://tw.nextmedia.com/applenews/article/art_id/32862262/IssueID/20101005
http://tw.nextmedia.com/applenews/article/art_id/32862262/IssueID/20101005
2010年9月5日 星期日
地球的年齡
引用自 This page is URL: http://pubs.usgs.gov/gip/geotime/age.html
AGE OF THE EARTH
So far scientists have not found a way to determine the exact age of the Earth directly from Earth rocks because Earth's oldest rocks have been recycled and destroyed by the process of plate tectonics. If there are any of Earth's primordial rocks left in their original state, they have not yet been found. Nevertheless, scientists have been able to determine the probable age of the Solar System and to calculate an age for the Earth by assuming that the Earth and the rest of the solid bodies in the Solar System formed at the same time and are, therefore, of the same age.
The ages of Earth and Moon rocks and of meteorites are measured by the decay of long-lived radioactive isotopes of elements that occur naturally in rocks and minerals and that decay with half lives of 700 million to more than 100 billion years to stable isotopes of other elements. These dating techniques, which are firmly grounded in physics and are known collectively as radiometric dating, are used to measure the last time that the rock being dated was either melted or disturbed sufficiently to rehomogenize its radioactive elements.
Ancient rocks exceeding 3.5 billion years in age are found on all of Earth's continents. The oldest rocks on Earth found so far are the Acasta Gneisses in northwestern Canada near Great Slave Lake (4.03 Ga) and the Isua Supracrustal rocks in West Greenland (3.7 to 3.8 Ga), but well-studied rocks nearly as old are also found in the Minnesota River Valley and northern Michigan (3.5-3.7 billion years), in Swaziland (3.4-3.5 billion years), and in Western Australia (3.4-3.6 billion years). [See Editor's Note.] These ancient rocks have been dated by a number of radiometric dating methods and the consistency of the results give scientists confidence that the ages are correct to within a few percent. An interesting feature of these ancient rocks is that they are not from any sort of "primordial crust" but are lava flows and sediments deposited in shallow water, an indication that Earth history began well before these rocks were deposited. In Western Australia, single zircon crystals found in younger sedimentary rocks have radiometric ages of as much as 4.3 billion years, making these tiny crystals the oldest materials to be found on Earth so far. The source rocks for these zircon crystals have not yet been found. The ages measured for Earth's oldest rocks and oldest crystals show that the Earth is at least 4.3 billion years in age but do not reveal the exact age of Earth's formation. The best age for the Earth (4.54 Ga) is based on old, presumed single-stage leads coupled with the Pb ratios in troilite from iron meteorites, specifically the Canyon Diablo meteorite. In addition, mineral grains (zircon) with U-Pb ages of 4.4 Ga have recently been reported from sedimentary rocks in west-central Australia. The Moon is a more primitive planet than Earth because it has not been disturbed by plate tectonics; thus, some of its more ancient rocks are more plentiful. Only a small number of rocks were returned to Earth by the six Apollo and three Luna missions. These rocks vary greatly in age, a reflection of their different ages of formation and their subsequent histories. The oldest dated moon rocks, however, have ages between 4.4 and 4.5 billion years and provide a minimum age for the formation of our nearest planetary neighbor. Thousands of meteorites, which are fragments of asteroids that fall to Earth, have been recovered. These primitive objects provide the best ages for the time of formation of the Solar System. There are more than 70 meteorites, of different types, whose ages have been measured using radiometric dating techniques. The results show that the meteorites, and therefore the Solar System, formed between 4.53 and 4.58 billion years ago. The best age for the Earth comes not from dating individual rocks but by considering the Earth and meteorites as part of the same evolving system in which the isotopic composition of lead, specifically the ratio of lead-207 to lead-206 changes over time owing to the decay of radioactive uranium-235 and uranium-238, respectively. Scientists have used this approach to determine the time required for the isotopes in the Earth's oldest lead ores, of which there are only a few, to evolve from its primordial composition, as measured in uranium-free phases of iron meteorites, to its compositions at the time these lead ores separated from their mantle reservoirs. These calculations result in an age for the Earth and meteorites, and hence the Solar System, of 4.54 billion years with an uncertainty of less than 1 percent. To be precise, this age represents the last time that lead isotopes were homogeneous througout the inner Solar System and the time that lead and uranium was incorporated into the solid bodies of the Solar System. The age of 4.54 billion years found for the Solar System and Earth is consistent with current calculations of 11 to 13 billion years for the age of the Milky Way Galaxy (based on the stage of evolution of globular cluster stars) and the age of 10 to 15 billion years for the age of the Universe (based on the recession of distant galaxies).
For additional information on this subject, see G. Brent Dalrymple's The Age of the Earth, published by the Stanford University Press (Stanford, Calif.) in 1991 (492 p.).
基百科，自由的百科全書
跳轉到: 導航, 搜尋
現代的地質學和地球物理學大致上都認為地球的年齡大約在45.4億年(4.54 × 109年 ± 1%)。[1][2] 年齡的測量是對隕石採用放射測年進行。這與地球上的最古老的石頭和月岩的結果一致。
除此之外，也有測量是運用地球內的放射性元素和它蛻變生成的同位素，大致結果相同。
[編輯] 參考文獻
^ Age of the Earth. U.S. Geological Survey [2006-01-10].
^ Dalrymple, G. Brent. The age of the Earth in the twentieth century: a problem (mostly) solved. Special Publications, Geological Society of London. 2001, 190: 205–221. doi:10.1144/GSL.SP.2001.190.01.14.
AGE OF THE EARTH
So far scientists have not found a way to determine the exact age of the Earth directly from Earth rocks because Earth's oldest rocks have been recycled and destroyed by the process of plate tectonics. If there are any of Earth's primordial rocks left in their original state, they have not yet been found. Nevertheless, scientists have been able to determine the probable age of the Solar System and to calculate an age for the Earth by assuming that the Earth and the rest of the solid bodies in the Solar System formed at the same time and are, therefore, of the same age.
The ages of Earth and Moon rocks and of meteorites are measured by the decay of long-lived radioactive isotopes of elements that occur naturally in rocks and minerals and that decay with half lives of 700 million to more than 100 billion years to stable isotopes of other elements. These dating techniques, which are firmly grounded in physics and are known collectively as radiometric dating, are used to measure the last time that the rock being dated was either melted or disturbed sufficiently to rehomogenize its radioactive elements.
Ancient rocks exceeding 3.5 billion years in age are found on all of Earth's continents. The oldest rocks on Earth found so far are the Acasta Gneisses in northwestern Canada near Great Slave Lake (4.03 Ga) and the Isua Supracrustal rocks in West Greenland (3.7 to 3.8 Ga), but well-studied rocks nearly as old are also found in the Minnesota River Valley and northern Michigan (3.5-3.7 billion years), in Swaziland (3.4-3.5 billion years), and in Western Australia (3.4-3.6 billion years). [See Editor's Note.] These ancient rocks have been dated by a number of radiometric dating methods and the consistency of the results give scientists confidence that the ages are correct to within a few percent. An interesting feature of these ancient rocks is that they are not from any sort of "primordial crust" but are lava flows and sediments deposited in shallow water, an indication that Earth history began well before these rocks were deposited. In Western Australia, single zircon crystals found in younger sedimentary rocks have radiometric ages of as much as 4.3 billion years, making these tiny crystals the oldest materials to be found on Earth so far. The source rocks for these zircon crystals have not yet been found. The ages measured for Earth's oldest rocks and oldest crystals show that the Earth is at least 4.3 billion years in age but do not reveal the exact age of Earth's formation. The best age for the Earth (4.54 Ga) is based on old, presumed single-stage leads coupled with the Pb ratios in troilite from iron meteorites, specifically the Canyon Diablo meteorite. In addition, mineral grains (zircon) with U-Pb ages of 4.4 Ga have recently been reported from sedimentary rocks in west-central Australia. The Moon is a more primitive planet than Earth because it has not been disturbed by plate tectonics; thus, some of its more ancient rocks are more plentiful. Only a small number of rocks were returned to Earth by the six Apollo and three Luna missions. These rocks vary greatly in age, a reflection of their different ages of formation and their subsequent histories. The oldest dated moon rocks, however, have ages between 4.4 and 4.5 billion years and provide a minimum age for the formation of our nearest planetary neighbor. Thousands of meteorites, which are fragments of asteroids that fall to Earth, have been recovered. These primitive objects provide the best ages for the time of formation of the Solar System. There are more than 70 meteorites, of different types, whose ages have been measured using radiometric dating techniques. The results show that the meteorites, and therefore the Solar System, formed between 4.53 and 4.58 billion years ago. The best age for the Earth comes not from dating individual rocks but by considering the Earth and meteorites as part of the same evolving system in which the isotopic composition of lead, specifically the ratio of lead-207 to lead-206 changes over time owing to the decay of radioactive uranium-235 and uranium-238, respectively. Scientists have used this approach to determine the time required for the isotopes in the Earth's oldest lead ores, of which there are only a few, to evolve from its primordial composition, as measured in uranium-free phases of iron meteorites, to its compositions at the time these lead ores separated from their mantle reservoirs. These calculations result in an age for the Earth and meteorites, and hence the Solar System, of 4.54 billion years with an uncertainty of less than 1 percent. To be precise, this age represents the last time that lead isotopes were homogeneous througout the inner Solar System and the time that lead and uranium was incorporated into the solid bodies of the Solar System. The age of 4.54 billion years found for the Solar System and Earth is consistent with current calculations of 11 to 13 billion years for the age of the Milky Way Galaxy (based on the stage of evolution of globular cluster stars) and the age of 10 to 15 billion years for the age of the Universe (based on the recession of distant galaxies).
For additional information on this subject, see G. Brent Dalrymple's The Age of the Earth, published by the Stanford University Press (Stanford, Calif.) in 1991 (492 p.).
基百科，自由的百科全書
跳轉到: 導航, 搜尋
現代的地質學和地球物理學大致上都認為地球的年齡大約在45.4億年(4.54 × 109年 ± 1%)。[1][2] 年齡的測量是對隕石採用放射測年進行。這與地球上的最古老的石頭和月岩的結果一致。
除此之外，也有測量是運用地球內的放射性元素和它蛻變生成的同位素，大致結果相同。
[編輯] 參考文獻
^ Age of the Earth. U.S. Geological Survey [2006-01-10].
^ Dalrymple, G. Brent. The age of the Earth in the twentieth century: a problem (mostly) solved. Special Publications, Geological Society of London. 2001, 190: 205–221. doi:10.1144/GSL.SP.2001.190.01.14.
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