Molecular biologist.
It’s mostly a matter of what we don’t know. Paleontological evidence certainly shows that horseshoe crabs didn’t change much in their appearance. However, we just don’t know to what extent other aspects of their biology are as conserved. Therefore, it is just unscientific to say that horseshoe crabs are ‘living fossils’ or that they didn’t evolve for millions of years. They may have, they may not have
I would have to assume there’s some ecological pressure they’re either experiencing or shielded from. If they’re under environmental pressure, they are either exceptionally developed to endure environmental changes or they’re adapting to the environment in ways that don’t reflect in their physiology. If they’ve just found a niche biome where the ecological conditions are fairly static, and they’re well suited to the environment, what changes would you see other than some generic genetic drift?
Molecular biologist.
It’s mostly a matter of what we don’t know. Paleontological evidence certainly shows that horseshoe crabs didn’t change much in their appearance. However, we just don’t know to what extent other aspects of their biology are as conserved. Therefore, it is just unscientific to say that horseshoe crabs are ‘living fossils’ or that they didn’t evolve for millions of years. They may have, they may not have
I would have to assume there’s some ecological pressure they’re either experiencing or shielded from. If they’re under environmental pressure, they are either exceptionally developed to endure environmental changes or they’re adapting to the environment in ways that don’t reflect in their physiology. If they’ve just found a niche biome where the ecological conditions are fairly static, and they’re well suited to the environment, what changes would you see other than some generic genetic drift?