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視覚システムの経路依存的進化の形態学的基礎
Rebecca M Varney1, Daniel I Speiser2, Johanna T Cannon1
1University of California, Santa Barbara, Santa Barbara, CA, USA.
まとめ
経路依存性や 進化の歴史は 視力のような複雑な特徴を 形成しています この研究は 貝殻の構造が 目の進化を制限する方法を明らかにし 自然界のシステムで 予測可能なものの 変数的な結果を示しています
科学分野:
- 進化生物学
- マクロ進化のパターン
- 発達上の制約
背景:
- 経路依存は,進化の軌道を制限することによって,マクロ進化の予測可能性に影響します.
- 自然系における経路依存を証明することは,独立した複製物が不足しているため,困難です.
- 複雑な特徴の進化を研究するためのモデルを提供しています
研究 の 目的:
- 自然集団内の複雑な特性の進化における経路依存性を実証する.
- 開発上の制約がマクロ進化の成果を形作る役割を調査する.
- ヒトの視覚系の進化を分析する
主な方法:
- 異なるシェルプレート構造を持つキトン系統の比較分析
- シェルプレートにおける感覚神経の開口数の検査
- 視覚システムの複雑性 (眼球の数) の形態学的評価
主要な成果:
- 2種類の分布した視覚系が キトンで独立して2回進化しました
- シェルプレートの感覚神経開口の数は 視覚系が進化したタイプを制限します
- より多くの開口を持つ系統は 何千もの眼球を進化させ 少ないものは 何百もの眼球を進化させました
結論:
- チトンの視覚系の進化は 経路に依存する急速なプロセスです
- 開発上の制約,特に殻の形態は,マクロ進化の結果を決定する.
- これらの結果は決定的 (制限) と ストキャスティック (変数) の両方です.
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