How scientists find thousands of new species every year

HostIt feels like we have mapped every inch of the planet by now. You can zoom in on almost any patch of dirt from your phone, so it's easy to think we have seen it all. But every single year, people who study the wild come back with news of thousands of new living things we never knew were there. I always thought the age of finding new life was something from the history books. Where are all these things hiding?

GuestMost of us think of a new find as something huge, like a new kind of tiger or a giant ape in the woods. But those big finds are actually pretty rare now. The reason we're still naming about twenty thousand new species every year is that most of life on earth is small, and it lives in places we just couldn't reach until now. We're talking about tiny wasps, strange fungi, and see-through fish. We have named about two million things so far, but some people think there might be eight million or even way more out there. We have basically only read the first few pages of the book of life.

HostTwenty thousand a year is a huge number. That's dozens of new things every day. But are these actually new, or are we just getting pickier? Like, is it just a beetle that has one extra spot on its wing so we give it a new name?

GuestThat's a fair point, and sometimes it does feel like we're splitting hairs. But the truth is more interesting. For a long time, we named things based on how they looked. If two frogs looked the same and lived in the same swamp, we called them the same thing. Now, we can look at the actual code of life inside them. We're finding out that two bugs might look like twins, but their inner workings are so different that they can't even have babies together. They have been on different paths for millions of years. So, we're not just finding new things in the wild; we're finding them in the drawers of museums where they have been sitting for a hundred years because we finally have the tools to see what they really are.

HostSo we're finding them in old boxes, sure. But you mentioned places we couldn't reach before. I thought we had been everywhere.

GuestNot even close. Think about the bottom of the sea. We have better maps of the moon than we do of the deep ocean floor. We're just now sending robots down into these deep trenches that are miles down. Every time a camera hits the bottom, we see things that look like they came from another planet. There are worms that eat bones and fish with glowing heads. And it's not just the deep sea. We're finding new things in the tops of the tallest trees in the rainforest and even deep inside caves that have been sealed off for ages. Even the soil in your backyard is a bit of a mystery. There are more kinds of life in a handful of dirt than there are people on the whole planet. We just didn't have the tech to pick them apart until now.

HostWait, if they're that small, how do you even find them? You can't just walk through the woods with a net and hope to catch something that tiny.

GuestThat's where the real shift is happening. We have this new trick where we can just take a cup of water from a river or a scoop of dirt from a forest and look for the bits of life left behind. Every living thing drops tiny bits of itself as it moves, like skin or waste. We call this environmental DNA. It's like a ghost trail. We can run a test on that water and see a list of every fish, frog, and bug that touched it. We're finding signs of animals we have never seen with our own eyes. It's like being a detective where the clues are floating in the air and water.

HostThat sounds a bit like cheating. If you only have a bit of code from a cup of water, can you really say you found a new animal? It feels a bit thin if you haven't actually held it or seen it move.

GuestIt does feel a bit like ghost hunting, and it causes a lot of talk among the experts. Usually, to say something is new, you need a body. You need to show the physical thing and put it in a museum. But in the deep sea or a thick jungle, that's hard. The code tells us something is there, so then we know where to go look. We're also using smart computers now to look through thousands of photos from trail cameras. These computers can spot a tiny change in a bird's feathers or a lizard's skin that a human eye would miss. It speeds everything up.

HostDoes it actually matter, though? If there's a new kind of tiny moss or a fly in a cave no one ever visits, why does it change anything for us?

GuestIt matters because every one of these things has a job. They're like parts in a giant machine. If we don't know the parts exist, we don't know how the machine works. Some of these new plants or molds we find have chemicals that could be the next big medicine. Others might be the key to keeping our food growing as the weather changes. But the real kick is that many of these things are disappearing before we even give them a name. We're in a race to find them so we can try to save the places where they live.

HostIt's a race where we're still figuring out who all the players are.

GuestWe're basically trying to write the full list of life on earth while the library is starting to burn down.

HostThe world map on our phones might look finished, but the closer we look at a single drop of water, the more we realize how much of the story is still missing.

GuestPeople often think we have reached the end of what there's to know, but we're actually just getting started.

HostThe dirt under our feet and the water in our streams are full of neighbors we have lived next to for forever without ever saying hello.