Prosanta Chakrabarty : Clues to prehistoric times, found in blind cavefish

Prosanta Chakrabarty at TED2016
Clues to prehistoric times, found in blind cavefish (transcript)
Summary
The speaker’s a dream is really fantastic. It's to discover and save new species as an ichthyologist who studies about fishes. It leads to studying and telling about the geology of the planet and the biology of how we see.
It recently turns out that new species hide in caves.
In caves, some fish species start to adapt to the dark, cold, and cave environment. Strangely, they lose their eyes and eyesight. They couldn't move make us imagine that the continents were last together.

In our earth, there are many species undiscovered that don't have names but many of them already extinct.
The study also leads to saving our environment.

Word in this story
cave /noun/ a large underground chamber, typically of natural origin, in a hillside or cliff.
Ichthyology /noun/ the branch of zoology that deals with fishes.
extinct /adj/  lost, died out, no longer existing