Biological Evolution: Unity and Diversity

  1. Health & Medicine

    Globetrotting microbes in airplane sewage may spread antibiotic resistance

    Along with harder-to-kill microbes, airplane sewage contains a diverse set of the genes that let bacteria evade antibiotics.

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  2. Health & Medicine

    Drug-resistant germs kill some 35,000 Americans each year

    The new mortality rate may be way low, some experts say. Also troubling are two new germs that have emerged as big and urgent threats.

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  3. Animals

    Why are bird eggs in cold climates darker colored?

    A global survey of bird egg color has revealed a simple trend: the colder the climate, the darker the egg.

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  4. Animals

    Piranhas and plant-eating kin replace half their teeth at once

    Piranhas and pacus shed and replace half of their teeth at a time. New teeth lock together as they push up from the jaw.

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  5. Life

    A new spin on lab-grown meat

    A technique inspired by how cotton candy is spun could help produce lab-grown meat at a lower cost and on a bigger scale.

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  6. Animals

    Blood vessels in their heads kept big dinos from overheating

    Giant dinosaurs evolved several ways to cool their blood and avoid heatstroke.

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  7. Animals

    What we can — and can’t — learn from our pets’ DNA

    Your dog or cat’s DNA is an open book. DNA tests tell people about their pet’s breed and attempt to predict things about its behavior and health.

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  8. Earth

    Explainer: Understanding geologic time

    Geologic time is unimaginably long. Geologists puzzle it out using a calendar called the Geologic Time Scale.

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  9. Animals

    Orca snot leads to a whale of a science-fair project

    DNA found in the mucus of orcas suggests that even though the traits of family pods may differ, these marine mammals all appear to belong to a single species.

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  10. Animals

    Cool Jobs: Diving for new medicines

    Scientists mix research with underwater adventure as they search the oceans for new chemicals to treat infections, cancer and more.

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  11. Genetics

    Explainer: Why scientists sometimes ‘knock out’ genes

    How do we learn what a particular molecule does in the body? To find out, scientists often 'knock out' the gene that makes it. Here’s how.

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  12. Health & Medicine

    Explainer: What is a hormone?

    Various tissues secrete special chemicals, known as hormones. They travel, usually in blood, to a particular distant site where they tell certain cells it’s time to go to work.

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