Bacteria have been fighting viruses for billions of years, and some of them keep a record of every attack. They clip a short piece of the invader’s DNA and file it in their own genome, so the next time that virus shows up, they recognize it and cut it apart. Scientists turned that ancient defense into a gene-editing tool cheap and precise enough to change biology labs everywhere. So how does CRISPR work? It comes down to a cutting protein, […]
Right now, on autumn nights, millions of small songbirds are flying south in the dark. Most of them fly alone, and many of the young ones are making the trip for the first time, with no parent to follow and no idea what their destination looks like. Yet they head in the right direction. How do birds navigate like that? Biologists now know that birds carry several compasses: one that reads the sun, one that reads the stars, and one […]
Slice into an onion and your eyes soon start to sting and water. Nothing in the whole onion is doing this. The irritant doesn’t exist until the knife goes in, and it’s made on the spot by a chain of chemistry that takes a fraction of a second. So why onions make you cry comes down to two enzymes, one unstable sulfur molecule and a discovery from 2002 that showed the textbook explanation was missing a step. Why onions make […]
The story goes like this: if a baby’s heart beats faster than 140 beats per minute, it’s a girl, and if it’s slower, it’s a boy. It’s one of the most repeated pregnancy myths, and unlike a lot of folklore, it makes a claim that can be tested. Researchers have tested it, several times. So, fetal heart rate boy or girl: is there a real link? In the early weeks, which is where most of the careful research has looked, […]
UV radiations and melanin production Humans and chimpanzees had the same ancestor about seven million years ago. The changes occur with the passage of time and each of the species evolved individually; the chimpanzees are, however, less evolved because they lived in their original environment. As our history can be related, it is observed that chimpanzees commonly have white skin which is covered with hair. So, it can be predicted that humans had white skin. The lifestyle of humans and […]
Charles Lyell (1797–1875), The Progress of Geology …Let us imagine, that [those who explored the antiquities of Egypt in the 19th century], had…a firm belief that the banks of the Nile were never peopled by the human race before [their time], and that their faith in this dogma was as difficult to shake as the opinion of our ancestors, that the earth was never the abode of living beings until the creation of the present continents, and of the species now […]