The deep sea harp sponge has a series of vertical vanes that maximize surface area for passive suspension feeding. As one report explains:
Scientists believe the harp sponge has evolved this elaborate candelabra-like structure in order to increase the surface area it exposes to currents, much like sea fan corals. … “C. lyra is an extraordinary example of the kind of adaptations that animals must make in order to survive in such a hostile environment.”
Apparently these “scientists” do not understand evolution very well for in evolution nothing happens for any reason. It may sound good, but no species “has evolved” anything “in order to increase” anything else.
In fact, everything occurs spontaneously, for no reason. Random chance events, such as mutations, collectively just happened to construct the harp sponge (no, natural selection never designed anything).
The harp sponge was created by a long series of random mutations and the like which just happened to happen, and just happened to create and continue to improve a living, eating, reproducing population that ultimately led to the harp sponge.
Selection, nor anything else, caused those mutations to occur. And selection certainly did not cause certain, more effective, mutations to occur. Evolutionists cannot tell you what that sequence of mutations was. They cannot even determine a hypothetical, candidate sequence of mutations that could have created the sponge. But they know there was such a sequence. Why? Because they know evolution is a fact.