An introduction to biological systematics
An introduction to biological systematics

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

An introduction to biological systematics

2.3 What does relationship mean in systematics? G.G. Simpson

Activity 2

Timing: 0 hours 5 minutes

Dr. Patterson continues to look at Simpson’s answer to the meaning of ‘relationship’ in systematics, and illustrates this by referring to a diagrams showing how the systematist viewed the relationship between phylogeny and higher and lower taxa (Figure 4).

Figure 4 The relationship between phylogeny and higher and lower taxa, according to Simpson, G. G. (1961) Principles of Animal Taxonomy, p. 190, Figure 19 (redrawn). (a) 'Phylogenetic tree with stems and branches incorrectly conceptualized as corresponding with taxa at different levels'. (b) 'Same correctly subdivided into taxa.'
Download this audio clip.Audio player: Audio clip 3
Skip transcript: Audio clip 3

Transcript: Audio clip 3

Dr. Colin Patterson
We can understand and criticise Simpson's solution better with the help of a diagram, which shows his idea of incorrect and correct ways of looking at a phylogenetic tree.
In the left hand tree, the successive levels are equated with taxa, and the result's a family containing two genera, each with two species. Now Simpson called this idea ‘flatly false’, and said that the correct classification is the one in the right hand diagram, where we have a family containing three genera - two living ones with two species, and a third ancestral genus with three species.
End transcript: Audio clip 3
Audio clip 3
Interactive feature not available in single page view (see it in standard view).

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to University-level study, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371