seaweed evolution

Most of the plants on earth came from seaweed, according to evolution. So, if it started from seaweed/algae, it means that the seaweed has all the base material to build almost everything. Seaweed/algae can be used both as a direct food for humans and as vegan gelatin for food and industry, for example basis for petri dishes used to culture cells, such as bacteria and small lavar.