400-million-year-old fossil upends our understanding of nature’s Fibonacci spirals: ScienceAlert

If your eyes are drawn to the arrangement of leaves on the stem of a plant, the texture of a pineapple, or the scales of a pinecone, you have inadvertently witnessed fine examples of mathematical patterns in nature.

What binds all these plant features together is their common feature of being arranged in spirals adhering to a numerical sequence called Fibonacci sequence.

Referred to as Fibonacci spirals for simplicity, these spirals are ubiquitous in plants and have fascinated scientists from Leonardo da Vinci to Charles Darwin.

This is the prevalence of Fibonacci spirals in plants today and is thought to represent A very old and reserved featuredating back to the earliest stages of plant development and continuing in its present forms.

However, we have New study challenges this point of view. We examined the spirals in the leaves and reproductive structure of a fossilized plant dating back 407 million years.

Surprisingly, we discovered that not all spirals observed in this particular species followed the same rule. Today, very few plants do not follow the Fibonacci pattern.

What are 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 are associated with the Fibonacci sequence – a set of numbers where each is the sum of the two numbers preceding it (1, 1, 2, 3, 5, 8, 13, 21, and so on).

These patterns are particularly prevalent in plants and can be identified with the naked eye. If you pick up a pinecone and look at the base, you can see the woody scales forming spirals that converge toward the point of attachment to the branch.

At first, you can only spot spirals in one direction. But look closely, and you can see both spirals clockwise and counterclockwise. Now count the number of spirals clockwise and counterclockwise, and in almost every case the number of spirals will be integers in the Fibonacci sequence.

This particular case is not an exceptional case. in Stady that analyzed 6,000 pinecones, Fibonacci spirals were found in 97 percent of the cones examined.

Fibonacci spirals don’t just exist in pine cones. They are common in other plant organs such as leaves and flowers.

If you look at the tip of a leafy leaf, like the one in the monkey puzzle tree, you can see the leaves are arranged in spirals starting at the tip and gradually winding their way around the stem. a Stady Of the 12,000 spirals from more than 650 plant species, Fibonacci spirals were found to occur in more than 90 percent of cases.

Because of their frequency in living plant species, it has long been believed that Fibonacci spirals were ancient and highly conserved in all plants. We set out to test this hypothesis by investigating early plant fossils.

Non-Fibonacci spirals in early plants

We examined leaf arrangement and reproduction in the first group of plants known to have developed leaves, called Algae Club.

Specifically, we studied the plant fossils of extinct algae species Astroxylon maki. The fossils we studied are now in museum collections in the United Kingdom and Germany but were originally collected from Rainey Chert Fossil site in northern Scotland.

We took pictures of thin slices of the fossils and then used digital reconstruction techniques to visualize an arrangement a. MakyiLeaves in 3D and identify snails.

Based on this analysis, we discovered that leaf arrangement was highly variable in a. Makyi. In fact, non-Fibonacci spirals were the most common arrangement. The discovery of non-Fibonacci spirals in such early fossils is surprising because they are so rare in plant species living today.

Distinctive evolutionary history

These findings change our understanding of Fibonacci spirals in terrestrial plants. They suggest that non-Fibonacci spirals were ancient in mosses, overturning the view that all leafy plants began to grow leaves that follow the Fibonacci pattern.

Furthermore, it indicates that the evolution of leaves and Fibonacci spirals in club mosses had an evolutionary history distinct from other groups of plants living today, such as ferns, conifers, and flowering plants. It is suggested that Fibonacci spirals appeared separately several times during plant evolution.

The work also adds another piece to the puzzle of a major evolutionary question — why are Fibonacci spirals so common in plants today?

This question still causes controversy among scholars. Various hypotheses have been proposed, incl Maximize the amount of light that every paper you receive or Pack the seeds efficiently. But our findings highlight how insights from fossils and plants such as algae may provide vital clues in finding an answer.

Sandy Hetheringtonplant evolutionary biologist, University of Edinburgh And Holly Ann TurnerPhD Candidate, Paleontology, University College Cork

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