不同的驱动器的多样化为身体的延长和肢体的缩小在融合蛇形的
Maxwell T Olson1, Philip J Bergmann1
1Department of Biology, Clark University, 950 Main Street, Worcester, MA, USA.
概括
的蛇形身体进化是由息地和进化历史驱动的. 化石 (挖掘) 生活方式促进脊椎进化,而肢体减小与特定的血统有关,揭示了融合进化的放松约束.
科学领域:
- 进化生物学是进化的生物学.
- 比较形态学的比较形态学
- 脊椎动物的古生物学
背景情况:
- 由于类似的环境压力,融合进化导致非相关物种具有相似的特征.
- 在脊椎动物中,特别是状爬行动物中,具有缩小四肢的蛇形 (延长) 身体形式多次进化.
- 之前的假设表明基质运动驱动伸展和四肢缩小遵循类别特定的模式,但这仍然未经测试.
研究的目的:
- 为了研究类蛇形态的进化驱动因素.
- 为了比较息地特异性与群体特异性模型,用于树干脊椎,手指和手环的进化.
- 为了确定环境因素或进化史是否主要影响四肢缩小和身体延长.
主要方法:
- 对具有不同化石 (挖掘) 习惯和家族遗传背景的物种进行比较分析.
- 统计建模来测试息地特异性和类特异性进化速率对脊椎数量,数字数量和骨数量的适应性.
- 检查化石和非化石的进化模式,以确定不同的发育途径.
主要成果:
- 与其他物种相比,在化石和杂乱的息地中的表现出明显的脊椎,手指和肢体数量.
- 息地特定的进化速率最好解释了脊椎进化,挖掘物种显示了加速的速度.
- 数字和手环以特定类别的方式进化,这表明肢体减小存在特定血统的约束.
结论:
- 蛇形的四肢减少主要受到类型特定约束的影响,而不是息地.
- 骨性缓解了脊椎进化的功能限制,允许更大的身体形状多样化.
- 随着选择性压力,进化约束的放松是推动融合进化的关键机制.
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