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biology articles

Segmentation, a question of boundaries

Read the previous section: Spiral cleavage, an oblique matter. Annelids, arthropods and vertebrates show a remarkable morphological diversity (Chipman, 2010). Beneath this multiplicity of shapes and forms lies a common pattern of body organization—a trunk divided into repeated parts. This pattern and the developmental process that generates it are known as segmentation (Minelli and Fusco, […]

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articles biology

Spiral cleavage, an oblique matter

Read the previous section: Larvae as the epitome of evolution. By the end of the 19th century, a series of biologists had dedicated themselves to following and discovering the fate of individual cells of an embryo during ontogeny. These works, known as cell lineage studies1, were critical to disambiguate the relationship between ontogeny and phylogeny, […]

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articles biology

Larvae as the epitome of evolution

Read the previous section: What a larva is. Francis M. Balfour set the pace on discussions about the evolutionary importance of larvae by addressing many of the fundamental questions regarding larval evolution (Balfour, 1874; Balfour, 1880; Balfour, 1881). He wondered about the ancestry of larvae. Can larvae reveal the ancestral forms of metazoans? He indicated […]

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biology articles

Endless larval forms most beautiful: what a larva is

This text is a section of my PhD thesis. The Latin word lārva means evil spirit, ghost or mask1. In the 18th century, the naturalist Carolus Linnaeus was the first to employ the word larva to describe a stage in the life of an animal in which its adult form is still hidden or masked […]

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notes science

My PhD thesis in the blog post format

I wrote the introduction of my PhD thesis as a series of blog posts.

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biology notes

Nemertean laying eggs