Carl Zimmer writes the “Matter” column. He is the author of thirteen books, including “She Has Her Mother’s Laugh: The Powers, Perversions, and Potential of Heredity.” @carlzimmer • Facebook

Rebecca Robbins joined The Times in 2020 as a business reporter focused on covering Covid-19 vaccines. She has been reporting on health and medicine since 2015. @RebeccaDRobbins