Could Mudskippers Evolve into a Second Wave of Terrestrial Vertebrates?

Pondering the evolution and potential for mudskippers to become a second wave of terrestrial vertebrates is an intriguing thought experiment. However, the reality of their evolutionary path is more complex and constrained by the principles of natural selection and ecological niches.

Competition and Evolution

As mudskippers first appeared on the evolutionary stage, they found themselves competing with existing terrestrial vertebrates. By the time mudskippers were present, the ecological niches for terrestrial life were already occupied by a variety of established species. The prevailing theory suggests that mudskippers were not competitive enough to evolve into a large and diverse clade. This is analogous to the competition between chimpanzees and bonobos, who, despite their intelligence and adaptability, were not able to effectively compete with humans to build civilizations.

Furthermore, the idea of a “first wave” of terrestrial vertebrates is a misconception. Mudskippers, like frogs, have always been designed to live a dual lifestyle. They spend part of their lives in water and part on land, but they have always been mudskippers. Their evolutionary path is constrained by their physical and biological characteristics.

Natural Adaptation and Amphibious Lifestyle

Mudskippers have always been amphibious creatures, able to breathe air as long as they stay wet. This unique adaptation grants them the ability to extend their habitat into the intertidal zones, where they can live and move on land. Although they are capable of breathing air, they are not yet adapted to a fully terrestrial lifestyle. However, the potential for them to evolve further into a terrestrial form cannot be completely ruled out.

Theoretical Evolutionary Path

While mudskippers are not tetrapods (having four limbs), there is theoretical potential for them to evolve into a terrestrial form. If the right conditions were present—such as a significant ecological change or a mass extinction event—some mudskippers might adapt to fully terrestrial life. This adaptation would likely involve significant changes to their anatomy. Their fins might evolve into more robust limbs for walking, and they would need to develop more efficient respiratory and circulatory systems to thrive on land.

It is also worth noting that nature often surprises us with its creative solutions. The hypothetical evolution of mudskippers into terrestrial forms might entail entirely new mechanisms and strategies that we cannot yet predict. For example, they might walk in a "tripod" style using their two front fins and the tip of their tail, or they might develop an entirely new mode of locomotion that we have not yet observed.

In conclusion, while mudskippers are not the first wave of terrestrial vertebrates and are unlikely to spontaneously transform into a new clade due to competition with existing species, they do possess the potential to evolve into a fully terrestrial form under specific conditions. The fascinating possibilities of mudskipper evolution make them a fascinating subject of study in the field of evolutionary biology.