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標題: 寒武紀大爆發與前寒武紀Mistaken Point 生物群問題 你問我答 [打印本頁]

作者: Dinosaurprince    時間: 2016-10-3 02:04 PM     標題: 寒武紀大爆發與前寒武紀Mistaken Point 生物群問題 你問我答

大家好!之前我上了關於寒武紀大爆發的課,我而家幫手嘅lab都同寒武紀大爆發有關。我幚手個教授之前都幫nasa研究Mistaken Point 生物群。所以如果大家有興趣可以問我問題,我都可以post D paper 比大家。 只不過我而家考緊 graduate program,可能會比較忙,有機會遲左回答,請大家見諒。
作者: Dinosaurprince    時間: 2016-10-3 02:09 PM

Here is some of the paper for Cambrian explosion

附件: [One Explanation of Cambrian Explosion] PNAS-2013-Sperling-13446-51.pdf (2016-10-3 02:09 PM, 357.53 K) / 該附件被下載次數 80
http://www.fossilshk.com/forum/attachment.php?aid=8671
作者: c7    時間: 2016-10-3 02:29 PM

Hi Dinosaur Prince,
nasa有研究化石的?
作者: Dinosaurprince    時間: 2016-10-3 04:14 PM     標題: 回復 #3 c7 的帖子

有呀
NASA 有個太空生物學program,佢地希望透過研究地球原始生命既進化去估計地球以外既生物係點樣。而mistaken point之所以重要係因為同地球而家或者以前所有生物唔同所以nasa 希望可以有多少少資料去預計外星生命會係點樣
作者: trump    時間: 2016-10-4 11:20 AM

想問最早的寒武紀化石地層在那裡找到
作者: fossilshk    時間: 2016-10-6 05:13 AM



QUOTE:
原帖由 Dinosaurprince 於 2016-10-3 02:04 PM 發表
大家好!之前我上了關於寒武紀大爆發的課,我而家幫手嘅lab都同寒武紀大爆發有關。我幚手個教授之前都幫nasa研究Mistaken Point 生物群。所以如果大� ...
很高興見到你們當中很多個都向自己的理想進發, Dinosaurprince, Fion Ma, Franco 仔等等, 要繼續加油, 帶多點知識給我們會員分享
作者: rock-tw    時間: 2016-10-23 10:09 PM

小男孩現在變成專家了
我一樣想知道最早的寒武紀化石地層,及全世界的寒武紀化石地層
作者: Dinosaurprince    時間: 2016-10-28 08:27 AM     標題: 回復 #5 trump 的帖子

Sorry I had three midterms in last two week and actually I have another midterm about fish and amphibian evolution tomorrow.
The lowest Cambrian can be defined by certain trace fossil found in Spain, Newfoundland in Canada, part of western US and Namibia. However, what evolutionary biologist interested is the Cambrian explosion strata and the earliest one is in Chengjiang biota in China and then the Burgress in Canada.
作者: Dinosaurprince    時間: 2016-10-28 08:36 AM     標題: 回復 #7 rock-tw 的帖子

actually you could search the strata with geologic map
I think this is one of the map you can find for free: https://www.unavco.org/software/ ... rce_OneGeology.html
作者: 寒武紀    時間: 2016-11-1 07:42 AM



QUOTE:
原帖由 Dinosaurprince 於 2016-10-28 08:36 AM 發表
actually you could search the strata with geologic map
I think this is one of the map you can find for free: https://www.unavco.org/software/ ... rce_OneGeology.html

作者: trump    時間: 2016-11-16 09:39 PM

small shelly fauna小殼生物群是不是最早
作者: Dinosaurprince    時間: 2016-12-21 01:47 PM     標題: 回復 #11 trump 的帖子

It is possibly one of the earliest. But as a matter of fact, sometimes we are not sure if some of the small shelly fauna belongs to Ediacaran period or earliest cambrian period because we do not know exactly when did they first appear nor do we know when did animal started mineralize themselves. To say accurately in science, I can only say that the earliest cambrian fossil is trace fossil of Treptichnus pedum because its appearance defined as the beginning of Cambrian period while small shelly fauna may survive to cambrian from Ediacara
作者: Dinosaurprince    時間: 2016-12-21 01:50 PM

Anyway, if anyone interested I have a paper about the cause of cambrian explosion and explain why such a graduate radiation did not earlier than 541mya
作者: fossilshk    時間: 2016-12-21 06:21 PM



QUOTE:
原帖由 Dinosaurprince 於 2016-12-21 01:50 PM 發表
Anyway, if anyone interested I have a paper about the cause of cambrian explosion and explain why such a graduate radiation did not earlier than 541mya
Yes, we  are interested it. Please share with us.
作者: dragonfly    時間: 2016-12-23 01:25 PM     標題: 回復 #13 Dinosaurprince 的帖子

論文有沒有中文解釋,如果有更好
作者: 寒武紀    時間: 2016-12-27 01:15 AM



QUOTE:
原帖由 fossilshk 於 2016-12-21 06:21 PM 發表


Yes, we  are interested it. Please share with us.
x2
作者: Dinosaurprince    時間: 2017-1-8 11:39 AM

I lost some of my paper when my labtop was broken. But this two papers along with the paper I shared before are the most important one.

A major contribution of Cambrian Radiation is due to oxygen level increase in the ocean during "Snowball Earth" period because of low oxygen consumption in the community, higher oxygen solubility, and ice sheet preventing oceanic oxygen escaping to the atmosphere. As a result, higher oxygen concentration allow higher energy  foraging activity such as active predation when the climate was warming right after snowball earth period. Predation also trigger creation of armoue and other animal defense strategy in turns to promote radiation when opportunity available. That is the reason why the first evidence of predation and hard tissue such as armour only appear after cambrian radiation because both predation and building hard structure is energy expensive and it does not make sense to use that amount of energy when organism metabolism was low before cambrian explosion.  It is worth to note that not all animal phyla appear at the cambrian radiation. Some phyla may appear earlier such as cnidarian, nematode and possibly mollusk which may date back in ediacaran period or even possibly a billion years ago for nematode. Some phyla may appear after cambrian such as bryozoa (Ordovician) and I remember there was a phylum appear in Jurassic period (I am not quite sure if it is tardigrade, water bear or something else).

[ 本帖最後由 Dinosaurprince 於 2017-1-8 11:42 AM 編輯 ]

附件: Curr Biol 2014 Ghisalberti.pdf (2017-1-8 11:42 AM, 893.28 K) / 該附件被下載次數 83
http://www.fossilshk.com/forum/attachment.php?aid=8983

附件: Parfrey_Lahr_multicellularity_2013.pdf (2017-1-8 11:42 AM, 314.84 K) / 該附件被下載次數 86
http://www.fossilshk.com/forum/attachment.php?aid=8984
作者: Dinosaurprince    時間: 2017-1-8 11:43 AM     標題: 回復 #15 dragonfly 的帖子

When you know that 90%+ of academic paper is written in English, you know you better improve your English
作者: dragonfly    時間: 2017-1-10 03:59 PM

Ok, I will try to read..
作者: 好黃魚呀    時間: 2017-1-11 06:33 PM

Mistaken Point 是什麼意思
作者: Dinosaurprince    時間: 2017-1-12 05:57 AM     標題: 回復 #20 好黃魚呀 的帖子

https://en.wikipedia.org/wiki/Mistaken_Point_Ecological_Reserve
作者: 達爾文    時間: 2017-1-14 12:14 AM



QUOTE:
原帖由 Dinosaurprince 於 2017-1-12 05:57 AM 發表
https://en.wikipedia.org/wiki/Mistaken_Point_Ecological_Reserve
我閱讀過Mistaken Point 生物群的文章後,有些地方好像有點混亂,文章提及Mistaken Point 是最早的多細胞生物群,但其實埃迪卡拉動物群Ediacaran fauna 是5.8-6億年前,理應比Mistaken Point 早
作者: fossilshk    時間: 2017-1-18 02:19 AM

還有貴州的甕安生物群都是埃迪卡拉紀早期的生物
作者: Dinosaurprince    時間: 2017-1-20 05:34 PM     標題: 回復 #22 達爾文 的帖子

Ediacaran biota refer to different assemblage of late proterozoic muliticellular life rather than biota found only in Ediacara, Australia (I know this naming system is a little bit confusing) and mistaken point is considered as one of the oldest assemblage. In one of the article here, it said that the similar form of organism can be date back to around 610mya while mistaken point is more recent biota of older organism (I remember that they may have found or dated an older assemblage, thru i cannot find the article now)
作者: Dinosaurprince    時間: 2017-1-20 05:49 PM

I cannot put the two paper about the detail of ediacaran biota here, maybe I can send you guys via message or email   This weekend we have a seminar on how Snowball Earth in Cryogenian period contribute to Ediacaran radiation and evolution of multicelluarity, I will let you know about the seminar when I back

P.S. I am going to a research in Congo Basin for a month next Wed. I may not able to respond you guys until late Feb, but feel free to raise anything for discussion here




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