Researchers want to unlock genetics of the world’s tiniest animals

The world’s largest animals often get most of the spotlight—but some biologists argue the tiniest ones deserve just as much, if not even more, study. Now, with a roughly $1.66 million grant from the European Research Council, experts will soon begin examining these small (but biologically fascinating) creatures at an unprecedented scale.

According to a September 5 announcement, curator of herpetology at Denmark’s Natural History Museum and University of Copenhagen assistant professor Mark Scherz will spend the next five years on a new project called GEMINI (Genomics of Miniaturization in Vertebrates). With GEMINI, Scherz’s team will study how the evolutionary shrinking of animals like flea toads, dwarf pygmy goby fish, and bumblebee bats managed to cram all their biological components into such small packages—without sacrificing efficiency or health. In doing so, experts could learn how genetic efficiency and improvement manifests within some of the most literally overlooked species.

“Large animals are often the ones to grab our attention. But I think it to be just as fascinating how nature has managed to miniaturize the exact same vital organs and cram them into a less than one-centimeter-long frog,” Scherz said in a statement on Thursday. “Today, we know surprisingly little about how it all happens, and I want to change that.”

As he explains, previous studies examining miniature animals’ genomes have shown that “a kind of clean-up and innovation” occurs as they evolve to smaller sizes. Although a lot of this simplification takes place in the erasure of what is sometimes called “junk” DNA, some alterations occur across other genes, too. It’s this latter category that Scherz hopes to understand more over the next few years.

In the past, many evolutionary biologists subscribed to a theory known as “Cope’s rule,” which posited that species trend towards larger sizes as they continue to evolve. Now, however, experts know this isn’t always the case, for pretty clear reasons.

“Animals cannot just keep growing larger and larger. At some point, physiology—exchange of heat, water, and oxygen—sets a limit, as does gravity,” said Scherz. “As such, there must be phases where body size reduces, in order for there to be a trend toward increased size at all.”

Scherz believes that contrary to Cope’s rule, smaller animals might actually be “where the real major innovations happen.” Think of it this way: A version of essentially every vital organ in your body also exists in the flea frog, the world’s smallest vertebrate discovered only last year in Brazil. All the same biological functions keeping the seven-millimeter-long amphibian alive can be found in humans, elephants, as well as blue whales—the Earth’s largest animals. But the flea toad pulls all that off at a fraction of the energy.

[Related: A new evolutionary theory could explain the mystery of shrinking animals.]

“Everyone’s attention is on blue whales and elephants. Any child you ask can tell you about the largest land mammal and the largest marine mammal and the largest dinosaur that has ever lived. But scaling up and getting bigger is not a big problem,” Scherz said. “It is a far more impressive feat to have [practically] everything in a twenty-three-tonne blue whale compressed into a seven-millimeter package.”

Speaking with Popular Science through email, Scherz says he believes his findings will see a lot of applications across the biomedical, bioengineering, and biotechnology industries.

“Bioengineering and biotechnology are constantly looking to nature for inspiration and demonstration of what is possible, and in a time where technology itself is undergoing extreme miniaturization, looking to nature’s primary examples of what complexity is possible at remarkably small size is going to be key.”