English

Eutacticity in sea urchin evolution

Quantitative Methods 2021-11-05 v1

Abstract

An eutactic star, in a n-dimensional space, is a set of N vectors which can be viewed as the projection of N orthogonal vectors in a N-dimensional space. By adequately associating a star of vectors to a particular sea urchin we propose that a measure of the eutacticity of the star constitutes a measure of the regularity of the sea urchin. Then we study changes of regularity (eutacticity) in a macroevolutive and taxonomic level of sea urchins belonging to the Echinoidea Class. An analysis considering changes through geological time suggests a high degree of regularity in the shape of these organisms through their evolution. Rare deviations from regularity measured in Holasteroida order are discussed.

Cite

@article{arxiv.0708.1256,
  title  = {Eutacticity in sea urchin evolution},
  author = {J. López-Sauceda and J. L. Aragón},
  journal= {arXiv preprint arXiv:0708.1256},
  year   = {2021}
}

Comments

17 pages, 6 figures

R2 v1 2026-06-21T09:06:07.258Z