In tomorrow’s New York Times, I dig up some of the fossil viruses that have been buried in our genome for tens of millions of years.
This is a subject I’ve explored here on the Loom before (1, 2), but now is a great time to stop and take stock of just how much progress scientists have made in exhuming the ancient invaders that helped make us what we are.
There was one dimension of this research that I didn’t have space to describe, but it’s too cool to let go unmentioned. In the article, I describe a virus protein called syncitin that is essential for placentas to develop. Cells push the protein to their surface, where it lets them latch onto other cells, fusing together to create a special layer through which nutrients can pass from mother to child. The protein got its start on viruses, which use it to latch onto host cells and fuse to them, allowing their genes to slip in.
But recent research has revealed an intriguing new twist to our viral legacy. It turns out that the viral surface protein in question has a second job. It also tamps down the immune system of its host. If the protein is altered to make it unable to suppress the immune response, viruses cannot successfully infect their hosts.
Thierry Heidmann, a leading paleovirologist whom I spoke to for the article, suspects that this second function may have been critical in the evolution of the placenta. That’s because there are two major challenges to being a placental mammal. First off, mothers need to be able supply their embryos with lots of nutrition for a long time through their circulatory system. Second, they have to cool down their immune systems. A baby’s tissues would otherwise look to the mother’s immune system like foreign tissue and be quickly rejected. So it’s possible that viruses not only let mothers feed their babies, but not kill them either.
This is a story that’s just going to get cooler, so expect updates as necessary.
Go Further
Animals
- How can we protect grizzlies from their biggest threat—trains?How can we protect grizzlies from their biggest threat—trains?
- This ‘saber-toothed’ salmon wasn’t quite what we thoughtThis ‘saber-toothed’ salmon wasn’t quite what we thought
- Why this rhino-zebra friendship makes perfect senseWhy this rhino-zebra friendship makes perfect sense
- When did bioluminescence evolve? It’s older than we thought.When did bioluminescence evolve? It’s older than we thought.
- Soy, skim … spider. Are any of these technically milk?Soy, skim … spider. Are any of these technically milk?
Environment
- Are the Great Lakes the key to solving America’s emissions conundrum?Are the Great Lakes the key to solving America’s emissions conundrum?
- The world’s historic sites face climate change. Can Petra lead the way?The world’s historic sites face climate change. Can Petra lead the way?
- This pristine piece of the Amazon shows nature’s resilienceThis pristine piece of the Amazon shows nature’s resilience
- Listen to 30 years of climate change transformed into haunting musicListen to 30 years of climate change transformed into haunting music
History & Culture
- Meet the original members of the tortured poets departmentMeet the original members of the tortured poets department
- Séances at the White House? Why these first ladies turned to the occultSéances at the White House? Why these first ladies turned to the occult
- Gambling is everywhere now. When is that a problem?Gambling is everywhere now. When is that a problem?
- Beauty is pain—at least it was in 17th-century SpainBeauty is pain—at least it was in 17th-century Spain
Science
- Here's how astronomers found one of the rarest phenomenons in spaceHere's how astronomers found one of the rarest phenomenons in space
- Not an extrovert or introvert? There’s a word for that.Not an extrovert or introvert? There’s a word for that.
- NASA has a plan to clean up space junk—but is going green enough?NASA has a plan to clean up space junk—but is going green enough?
- Soy, skim … spider. Are any of these technically milk?Soy, skim … spider. Are any of these technically milk?
Travel
- Could Mexico's Chepe Express be the ultimate slow rail adventure?Could Mexico's Chepe Express be the ultimate slow rail adventure?
- What it's like to hike the Camino del Mayab in MexicoWhat it's like to hike the Camino del Mayab in Mexico