坎布里亚底部的心脏动力解决了欧类大脑的起源
Nicholas J Strausfeld1, Xianguang Hou2, Marcel E Sayre3,4
1Department of Neuroscience, University of Arizona, Tucson, AZ, USA.
概括
骨化的神经系统的心脏带揭示了一个未分割的头部和大脑. 这一发现澄清了关节动物头部的演变,早于欧类动物头部的发展.
科学领域:
- 古生物学
- 进化生物学
- 神经科学
背景情况:
- 关节动物头部和大脑的起源和进化仍然不太清楚,不同的形态和基因关系挑战了统一的解释.
- 调和这些差异一直是进化生物学中的一个长期挑战.
研究的目的:
- 解释关节动物头部和大脑的进化历史.
- 为关节动物观察到的多样性形态和遗传关系提供统一的理由.
主要方法:
- 对坎布里亚低层杆动物心动的化石神经系统的分析.
- 头部域与干组关节动物的比较形态.
- 同类基因表达模式与现存的类动物对齐.
主要成果:
- 石化的神经系统表现出一个未分割的头部和大脑,有三个不同的脑区.
- 这些领域与服务于干部的内侧神经系统分开.
- 每个头部区域都与前肠的组成部分和头部附属部分保持一致.
- 形态对应性和基因表达模式表明这些头部域早于欧类头部进化.
结论:
- 脑区的心动脉是欧类头部的前体.
- 这些域对应于现存的类动物和类动物的大脑中的神经元.
- 这一发现为关节动物头部和大脑的演变提供了统一的观点.
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