Fibonacci spirals

Subject : Science and technology

Section: Msc

Concept :

A new study, based on 407-million-year-old fossils challenges the belief that Fibonacci spirals represent an ancient and highly conserved feature, dating back to the earliest stages of plant evolution and persisting in their present forms.

Non-Fibonacci spirals in early plants

Surprisingly, the study discovered that all of the spirals observed in this particular species did not follow this same rule. Today, only a very few plants don’t follow a Fibonacci pattern.
We examined the arrangement of leaves and reproductive structures in the first group of plants known to have developed leaves, called clubmosses.
Specifically, we studied plant fossils of the extinct clubmoss species Asteroxylon mackiei. The fossils we studied are now housed in museum collections in the UK and Germany but were originally collected from the Rhynie chert – a fossil site in northern Scotland.
Images of thin slices of fossils and then used digital reconstruction techniques to visualise the arrangement of Asteroxylon mackiei’s leaves in 3D and quantify the spirals.
Based on this analysis, we discovered that leaf arrangement was highly variable in Asteroxylon mackiei. In fact, non-Fibonacci spirals were the most common arrangement. The discovery of non-Fibonacci spirals in such an early fossil is surprising as they are very rare in living plant species today.

About Fibonacci spirals

Spirals occur frequently in nature and can be seen in plant leaves, animal shells and even in the double helix of our DNA.
In most cases, these spirals relate to the Fibonacci sequence.
Fibonacci sequence is a set of numbers where each is the sum of the two numbers that precede it (1, 1, 2, 3, 5, 8, 13, 21 and so on).
These patterns are particularly widespread in plants and can even be recognised with the naked eye.
Due to their frequency in living plant species, it has long been thought that Fibonacci spirals were ancient and highly conserved in all plants.