Tiny Fish Smell for Miles
Fish hatchlings no more than a few millimeters in size are able to find their way home by smell, scientists from James Cook University found. After hatching from a reef, baby fish are often swept out to sea for miles. The scientists were curious how they are able to get back to the particular spot where they were born. “The team exposed tiny fish larvae in a tank to pure streams of water from four different reefs,” the article says. “To their amazement, within minutes a surprisingly high percentage of baby fish had congregated in the water flow from their home reef.” Every reef has a unique chemical signature. The scientists were surprised that so soon after hatching fish were able to detect that signature and use it to home in on home.
The press release speculates on how this trait causes biodiversity by evolution. “We think some fishes then choose currents that smell like ‘home’ and swim up them. The ones that cannot do this perish. The ones that get home preserve the unique ‘ethnic’ make-up of their tribe — and so continue the process of evolving into separate new species.”
The team did not see the fish evolving into separate species. Even if they had, they would be talking about microevolution, which is not controversial. It would contribute no argument to how the fish emerged in the first place with their remarkable sense of smell.
For a fascinating documentary on how a salmon is able to smell its way from the open sea all the way back up to the particular tributary where it was born, see the film Wonders of God’s Creation by Moody Video.