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Do you dream of discovering rugged coastlines, lush landscapes and lively city markets,

then sail from Portsmouth or Plymouth directly to Santander with Brittany ferries

and experience Spain like never before.

Wind through the city's charming streets before sampling Santander's succulent fresh seafood.

Trace your way through history at the Palacio de Magdalena, then absorb the panoramic views of the white sand bays.

Reimagined your Spanish adventure and visit the Guardian.com forward

slash Brittany Ferries Cantabria. This message was paid for by Brittany Ferries.

It's time to uncover hidden gems in Southeast Asia, with the help of Hilton's expert

concierge team. Be introduced to the magic of traditional water puppetry in Vietnam

discover where to ask a wish of the four-faced Buddha in Thailand

or where you can dine in the sky while drinking in Singapore's sunset

visit the guardian.com forward slash travel southeast Asia

and discover five-star unforgettable travel with Hilton.

This message was paid for by Hilton.

When Yip DeRoda started his academic career, he had one subject in mind.

I was very interested in studying infectious disease in parasites.

But a chance discovery, while studying malaria-like parasites in monarch butterflies,

took him down a different path entirely.

I realized that monarch butterflies are specialist feeders, so the caterpers can only eat

milkweed, but are different types of milkweed and some have a lot of toxins.

You might think the butterflies would want to avoid the milkweed that contain toxins,

...