Introduction

Charles Darwin, the father of evolutionary theory, was fascinated—and deeply puzzled—by many aspects of natural history. Among these, one problem stood out so much that he famously called it his “abominable mystery.” This phrase has echoed through generations of botanists and evolutionary scientists, symbolizing a profound enigma in the story of plant evolution.

What Was Darwin’s “Abominable Mystery”?

• In 1879, Darwin wrote to his friend, botanist Joseph Hooker, expressing his bewilderment at the sudden appearance and rapid diversification of flowering plants (angiosperms) in the fossil record.

• Darwin observed that angiosperms seemed to emerge abruptly and in great diversity during the Cretaceous period, with no clear evolutionary intermediates linking them to earlier plant groups12345.

• He was troubled by how quickly these “higher plants” became dominant across ecosystems, which seemed to contradict the gradualism central to his theory of evolution5.

Why Did This Puzzle Darwin?

• The fossil record showed gymnosperms and other seed plants existing for millions of years, but angiosperms appeared to “arrive out of nowhere,” already highly diverse and widespread25.

• Darwin worried that this apparent leap in plant evolution could be used to argue against natural selection and for divine intervention, a point debated among his contemporaries5.

• The lack of transitional fossils and the rapid ecological success of angiosperms made it difficult to explain their evolutionary origins using the data available in Darwin’s time45.

The Lasting Impact of the “Abominable Mystery”

• Darwin’s “abominable mystery” has become a central question in plant evolutionary biology, inspiring generations of research into the origins, early evolution, and ecological dominance of angiosperms8.

• While significant progress has been made, including discoveries of early angiosperm fossils and genetic studies, the full story of their origin and explosive diversification remains an active area of scientific inquiry58.

The Correct Answer

Given the options:

1. Angiosperms

2. Microorganisms

3. Beetles

4. Birds

The correct answer is:

(1) Angiosperms

Conclusion

Darwin’s “abominable mystery” refers specifically to the origin and rapid diversification of angiosperms, or flowering plants. This puzzle remains one of the most intriguing and enduring questions in evolutionary biology, highlighting the complexities and surprises of life’s history on Earth.