Volvox
I’m a worm, get me out of here
Natural selection of spaghetti worms
Summary
After acclimatising the local bird population to a new source of food, equal numbers of two different-coloured spaghetti 'worms' are presented to birds. Each day (or at regular intervals), the remaining 'worms' are allowed to 'breed' and the two colour morphs are replaced in proportion to those which remain. Over time, the proportion of the type of 'worms' that are left uneaten by the birds increases, thereby simulating directional selection.
Educational objectives
Students will learn how to plan, carry out and interpret data from a practical investigation. They should also learn about directional selection.
Pre-knowledge and skills required by students
A basic knowledge of the principle of evolution by natural selection would be useful.
Time taken in lesson
50 minutes x 3
Preparation time
60 minutes
Specialist equipment and materials required
Spaghetti, food colouring
Context where originally used
We suggest that, as it is described here, the investigation is best suited to 11–13 year-old students. With modification, however, it could be used by much younger students, or with more advanced students if more complex experiments and analyses were carried out.
Additional information
This protocol was originally devised for the Wellcome Trust's 'Survival Rivals' project. 'Survival Rivals' is the Wellcome Trust's Darwin 200 offering for secondary schools in the UK (www.survivalrivals.org). The Wellcome Trust is an independent charity that funds research to improve human and animal health (Registered charity No 210183).
Author
Dean Madden for the Wellcome Trust
Author address
NCBE
University of Reading
2 Earley Gate
Reading
RG6 6AU
Copyright HOLDER(s)
Text copyright © The Wellcome Trust, 2009
COPYRIGHT TERMS
This protocol is covered by a Creative Commons 'attributed, non-commercial, share alike' licence. This means that you may use it, adapt it, translate it and so on. You may not use it for commercial purposes however, and you must mention the source of the original work (The Wellcome Trust). Any derivative works must be distributed on the same terms.
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