When genes are activated, the instructions encoded within their DNA are first transcribed into a related molecule called RNA. Shepherd’s colleague Elissa Pastuzyn showed that the Arc shells can enclose RNA and move it from one neuron to another. And that’s basically what retroviruses do—they use protein shells to…
Human nature as it now exists was formed in accord with the laws of evolution under conditions pertaining well before recorded human history. Fossils discovered in Ethiopia and Kenya now date human ancestors back at least 5 or 6 million years. Distinctly human species arose in Africa at least 2 million years ago…
Many species of terrestrial plants, including the skunk cabbage that sprouts in February in the woods of Princeton, New Jersey, where I live, are warm-blooded to a limited extent. For about two weeks the skunk cabbage maintains a warm temperature by rapidly metabolizing starch stored inside the part of its anatomy…
Crying evolved to serve the infant's purposes: to assure protection, adequate feeding, and nurturing for an organism that cannot care for itself. By definition, crying is designed to elicit a response, to activate emotions, to play on the empathy of another. The "other" is usually the mother or father or a related…
For hundreds of millions of years, Sex was the most efficient method for propagating information of dubious provenance: the origins of all those snippets of junk DNA are lost in the sands of reproductive history. Move aside, Sex: the world-wide Web has usurped your role. A single illegal download can propagate more…