Homoplasy, character function and nemertean systematics

• We question recent claims that cladistic analysis is inapplicable in nemerteans (phylum Nemertea) due to a supposedly high degree of convergence. We further argue that terms like convergence and parallelism are historical sayings and only make sense in a phylogenetic context. Therefore, an approach aiming to produce phylogenetic hypotheses cannot be rejected on the grounds of a high degree of convergence before the actual hypothesis. Convergence is not an empirical observation, but a conclusion made after an analysis. We also discuss the view that knowledge of a character's function is a prerequisite for phylogenetic analysis and conclude that this is an invalid approach. Function, like any other way of sharpening our observations, helps in formulating non-phylogenetic hypotheses of homology, but the crucial test is congruence with other characters on a phylogeny.

Subject headings

NATURVETENSKAP  -- Biologi -- Biologisk systematik (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biological Systematics (hsv//eng)

NATURVETENSKAP  -- Biologi -- Zoologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Zoology (hsv//eng)

Keyword

Evolutionary Biology

Evolutionsbiologi

Publication and Content Type

ref (subject category)

art (subject category)