"Lophenteropneust"仮説は,新しい深海のヘミコルド類の収集と写真によって否定されました
Nicholas D Holland1, David A Clague, Dennis P Gordon
1Marine Biology Research Division, Scripps Institution of Oceanography (UCSD), La Jolla, California 92093-0202, USA. nholland@ucsd.edu
Nature
|March 18, 2005
まとめ
以前は,襟の触手を持っていると考えられていた深海半弦類は,それらが欠けていることが判明しました. この発見は,ロフェンテロプネウスト仮説とその影響がデュテロストームの進化に及ぼす影響に異議を唱える.
科学分野:
- マリン・バイオロジー マリン・バイオロジー
- 進化生物学の進化生物学について
- 動物学 動物学
背景:
- ロフェンテロプネウストとして知られる深海のヘミコルド類は観察されたが,採集されなかった.
- これらの生物は,襟の触手,橋渡しの腸内肺,そしてペトロブランクの体プランを有すると仮定された.
- ロフェンテロプネウスト仮説は,デウテロストームのエンテロプネウストのような祖先状態を示唆し,脊椎動物の進化論に影響を与えた.
研究 の 目的:
- 広い襟の深海の腸内肺の最初の採集された標本を記述するために.
- 触手の存在を調査するために,広い襟の深海のヘミコルド.
- ロフェンテロプネウスト仮説とその進化的含意を再評価する.
主な方法:
- 新種の深海の腸内肺菌標本の収集と形態学的分析.
- 広い襟の腸内神経体の深海写真の調査.
- 形態学的特徴と既存の仮説の比較分析.
主要な成果:
- 新しい家族,属,および種が,広い襟の深海のエンテロプネウストについて記述されました.
- 採集した標本の首輪は,幅が広いにもかかわらず,触手がなかった.
- 探知器の証拠は,調査した深海写真のいずれにも見つかりませんでした.
結論:
- ロフェントロプネウスト仮説は,低品質の深海画像の誤った解釈に基づいています.
- エントロプネウストのボディプランは,フィラムヘミコルダータの内では必ずしも基礎的とは限らない.
- この発見は,デウテロストームと脊椎動物の進化に関する考えを改めることを必要としています.
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