Species concepts and phylogenetics

Species concepts and phylogenetics Concepts of species proposed within the phylogenetic paradigm arecritically reviewed. Most so called ‘phylogenetic species concepts’ relyheavily on factors immaterial to phylogenetic hypotheses. Thus, theyhave limited empirical content and offer weak bases on which to makedecisions about real problems related to species. Any workable notion ofspecies relies on an explicit character analysis, rather than onabstract properties of lineages, narrative predications and speculationson tokogenetic relationships. Species only exist conjecturally, as thesmallest meaningful units for phylogenetic analysis, as based oncharacter evidence. Such an idea considers species to be conjecturesbased on similarity, that are subsequently subject to testing by theresults of analysis. Species, thus, are units of phylogenetic analysisin the same way as hypotheses of homology are units of comparablesimilarities, i.e. conjectures to be tested by congruence. Althoughmonophyly need not be demonstrated for species-level taxa, hypotheses ofrelationships are the only basis to refute species limits and guidenecessary rearrangements. The factor that leads to recognition ofspecies is similarity in observed traits. The concept of life cycle isintroduced as an important element in the discussion of species, as anefficient way to convey subsidiary notions of sexual dimorphism,polymorphism, polytypy and clusters of diagnosable semaphoronts. Thenotion of exemplars is used to expand the concept ofspecies-as-individual-organisms into a more generally usable concept.Species are therefore proposed for a diagnosable sample of(observed or inferred) life cycles represented by exemplars all of whichare hypothesized to attach to the same node in a cladogram, and whichare not structured into other similarly diagnosable clusters. Thisdefinition is character-based, potentially testable by reference to abranching diagram, and dispenses with reference to ancestor-descendantrelationships or regression into population concepts. It provides aworkable basis on which to proceed with phylogenetic analysis and abasis for that analysis to refute or refine species limits. A protocolis offered for testing hypotheses of species boundaries in cladograms. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Reviews in Fish Biology and Fisheries Springer Journals

Species concepts and phylogenetics

Loading next page...
Kluwer Academic Publishers
Copyright © 1999 by Kluwer Academic Publishers
Life Sciences; Freshwater & Marine Ecology; Zoology
Publisher site
See Article on Publisher Site


You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial