the price down to something affordable and took the second butterfly to the lab.
Dissection revealed more anomalies. Whole organs were displaced from their usual positions, and features conserved across
the entire order Lepidoptera were missing, or subtly altered. If all of these changes were due to a barrage of random mutations,
it was hard to imagine how the creature could have survived the larval stage, let alone ended up as such a beautifully formed,
perfectly functioning adult. You could expose generations of insects to teratogens until half of them grew heads at both ends
of their bodies, but nothing short of a few million years of separate evolution could have produced so many perfectly harmless
– or, for all Rajendra knew,beneficial – alterations. But how could this one species of swallowtail have been isolated longer than any other butterfly
in the world?
Radha carried out genetic tests. Attempts to determine the butterfly’s evolutionary genealogy with standard markers yielded
nonsensical results – but old, degraded DNA couldn’t be trusted. Rajendra begged the dealer to try to obtain a living specimen,
but nothing doing, that was too much trouble. However, he did reluctantly reveal the name of his supplier in Ambon. Rajendra
wrote to the man, three times, to no avail.
By 2006, the couple had scraped together enough money for Rajendra to travel to Ambon in person, and he’d taught himself enough
Bahasa Indonesian to speak to the supplier without an interpreter. No, the supplier couldn’t get him live specimens, or even
more dead ones. The butterflies had been collected by shipwrecked fishermen, killing time waiting to be rescued. No one visited
the island in question intentionally – there was no reason to – and the supplier couldn’t even point it out on a map.
‘Fishermen from where?’
‘Kai Besar.’
Rajendra phoned Radha. ‘Sell all my textbooks and wire me the money.’
With the help of the bemused fishermen, Rajendra collected dozens of pupae from the island; he had no idea what the chrysalis
stage would look like, so he grabbed a few examples of every variation he could find. Back in Calcutta, fifteen of the pupae
completed metamorphosis, and three yielded the mysterious swallowtail.
Fresh DNA only confirmed the old puzzles, and added new ones. Structural differences in the genes for neotenin and ecdysone,
two crucial developmental hormones, suggested that the butterfly’s ancestors had parted company from other insects three hundred
million years ago – roughly forty million years before the emergence of Lepidoptera. This conclusionwas obvious nonsense, and other genes told a far more believable story, but the discrepancy itself was remarkable.
Radha and Rajendra co-authored a paper describing their discoveries, but every journal to which they submitted it declined
publication. Their observations were absurd, and they could offer no explanation for them. Most of their peers reviewing the
work for the journals must have decided that they were simply incompetent.
One referee who’d read the paper for
Molecular Entomology
thought differently, and contacted Radha directly. She worked for Silk Rainbow, a Japanese biotechnology firm whose speciality
was using insect larvae to manufacture proteins that couldn’t be mass-produced successfully in bacteria or plant cells. Her
employers were intrigued by the butterfly’s genetic quirks; no immediate commercial applications were apparent, but they were
prepared to fund some blue-sky research. If Radha was willing to send her DNA samples, and her own tests confirmed the unpublished
results, the company would pay for an expedition to study the butterflies in the wild.
Prabir had pieced together most of this story long after the events had taken place – even when he’d been old enough to understand
the fuss over the butterfly, he hadn’t been paying much attention – but he could remember