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Research draft

clade

vr.tr.clade · PHY.LIV

Let an agent explain clades, relay phylogenetic concepts, methods and examples from evolutionary biology sources, describe the named terms and flag related concepts, and distinguish clades from grades or paraphyletic groups, polyphyletic groups, taxonomic ranks and species.

Thing Registry Physical world and living systems

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent explain clades, relay phylogenetic concepts, methods and examples from evolutionary biology sources, describe the named terms and flag related concepts, and distinguish clades from grades or paraphyletic groups, polyphyletic groups, taxonomic ranks and species.

A group of organisms consisting of a common ancestor and all of its descendants, also called a monophyletic group, the basic unit of phylogenetic systematics developed by Willi Hennig, identified by shared derived characters and DNA evidence; related terms the registry aliases name include crown groups, the last common ancestor of living members and all its descendants, basal clades that branch early in a tree, and species flocks, groups of closely related species that diversified rapidly in one area, such as cichlids of the African Great Lakes, while sibling species, species that are very similar but reproductively isolated, is a related concept rather than a type of clade. Clades may or may not be given formal ranks.

What it is for: Classifying organisms by evolutionary descent.

It can be explain monophyly and phylogenetics; relay methods; describe named terms; distinguish related groupings.

Distinguishing features

Monophyletic

Shared derived traits

Nested hierarchy

Rank-free possible

What it looks like

Not a physical object; shown as branches on phylogenetic trees.

Physical character

Hennig s phylogenetic systematics: 1950, English 1966 note

term clade: Julian Huxley, 1957 note

code: PhyloCode note - effective 2020

How it is recognised

Ancestor and all descendants

Crown group, sibling species, basal clade, species flock, monophyletic group

Grades are paraphyletic; polyphyletic groups lack a common ancestor within; ranks are labels; species are basic units

Related models

is a kind of - in registry terms

taxon

is studied in -

cladistics

includes -

crown group

is contrasted with -

paraphyly

In practice

Families and kinds

crown groups

stem groups

basal clades

species flocks

nested clades

Standards and regulation

PhyloCode

International Codes of Zoological and Botanical Nomenclature

Failure modes and hazards

Calling paraphyletic groups clades

Confusing clades and ranks

Misfiled species concept alias

Also called

crown groupsibling speciesbasal cladespecies flock

Where this came from

wikidata · CC0 1.0

Also registered as vr.tr.clade

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Understand What a clade is.

Science.

Definition

Definition.

Definition

Definition.

  1. What is a clade, and how does it differ from grades, polyphyletic groups, ranks and species? definition
  2. Is the question about classification, evolution or a specific group? boundary

Terms

Named terms.

Terms

Terms.

  1. What are crown groups, basal clades and species flocks, and what are sibling species? definition
  2. Which entry fits the specific term? action
Phylogenetics Methods.

Science.

Cladistics

Cladistics.

Cladistics

Cladistics.

  1. How do shared derived characters define clades? provenance
  2. Which references are standard? provenance

Molecular

Molecular phylogenetics.

Molecular

Molecular.

  1. How do DNA sequence methods infer clades? provenance
  2. Which sources are cited? provenance
Examples Examples.

Attribution.

Birds

Birds as dinosaurs.

Birds

Birds.

  1. Why are birds placed within the dinosaur clade? provenance
  2. Which entry fits Dinosauria? action

Reptiles

Paraphyletic groups.

Reptiles

Reptiles.

  1. Why is traditional Reptilia paraphyletic, and how do classifications handle it, with views attributed? provenance
  2. Is the presentation neutral and attributed? boundary
Context Diversification.

Context.

Species flocks

Cichlid flocks.

Species flocks

Species flocks.

  1. How did cichlid species flocks radiate in African lakes? provenance
  2. Which entry fits cichlid? action

PhyloCode

Rank-free naming.

PhyloCode

PhyloCode.

  1. What is the PhyloCode, and how does it differ from traditional codes? provenance
  2. Which entry fits PhyloCode? action

What the second pass must settle

  • The registry alias sibling species should be moved to species concept entries
  • Should crown group be a separate entry?
  • How should phylogenetic databases be linked?