Tuesday, September 11, 2012

Why god is so fond of beetles?

Beetles form insect order Coleoptera, which is very rich in diversity. JBS Haldane's quote "that god has an inordinate fondness for beetles" is used to portray this rather astonishing fact. Various experiments have been done to identify the reason for the larger diversity found in beetles. 

Reasons such as host specificity driven speciation, specifically herbivory and angiosperm evolution in particular is suspected.While this study has contradicted this line of reasoning based on large scale phylogenies.

Higher survival capabilities of the beetle lineages has been attributed to their pre-Cretaceous origins. Was this diversity a result of an adaptive radiation that has been sustained by further diversification into a variety of niches? Does the beetle have a better ability to adapt? What makes it more adaptable?

Do the reasons for the diversification come from predators and defense mechanisms that beetles had to develop to escape these predators. In fact beetles use mimicry, chemical defenses, strong mandibles or horns or spines to deter predators.

Sex chromosomes of beetles have interesting biology and could play a role in the generating diversity.Frequent changes in sex determination mechanisms as has been seen in many insect groups could be important.

Could the genome shed some light on the reasons? The genome of the red flour beetle (Tribolium castaneum) has been sequenced. Presence of genes involved in detoxification, development, cell-cell communication and various other genes involved in ability to interact with diverse environments might explain the extraordinary ability of the beetles to adapt.

On the contrary Haldane was a self professed atheist who thought that "My practice as a scientist is atheistic. That is to say, when I set up an experiment I assume no god, angel or devil is going to interfere with its course... I should therefore be intellectually dishonest if I were not also atheistic in the affairs of the world.". So may be he was making a more complicated point which we mere mortals have failed to comprehend?

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