Scientists thing protists evolved from archaea, which are simply single celled organisms.
The first plants evolved from an organism much like the multicellular green algae living today.
Algae
the protists
It is because protists are very diverse. The group has everything in it that is eukaryotic except for animals, plants and fungi.
Protists are a paraphyletic group because animals, fungi, and plants are the crown groups evolved from different lineages of the protists. They aren't included in the same group as protists taxonomically. This explains why the cladists consider the protist a paraphyletic group.
If your question is why are protists, fungi, animals, and plants part of the eukaryote group? The answer is because they all contain a true nucleus. Eu means true and karya means nucleus. Eukaryotes are organism with true nucleus. If protists, fungi, animals, and plants all belong to the above group then it seems that all organisms alive must belong to the above group right? Well there are those sometimes bothersome creatures that surround you at all times, they are even around you right now and they are not eukaryotes. No I am not talking about kids, I am talking about bacteria. Bacteria are not in this group because they do not contain a true nucleus. Bacteria contain a more primitive nucleus.
What were the first terrestrial animals?
Protists are a diverse collection of eukaryotic organisms but they are not plants, fungi, or animals.
Protists are a paraphyletic group because animals, fungi, and plants are the crown groups evolved from different lineages of the protists. They aren't included in the same group as protists taxonomically. This explains why the cladists consider the protist a paraphyletic group.
protists
the protists
It is because protists are very diverse. The group has everything in it that is eukaryotic except for animals, plants and fungi.
fish
Protists
protists
Precambrian
Protists are a paraphyletic group because animals, fungi, and plants are the crown groups evolved from different lineages of the protists. They aren't included in the same group as protists taxonomically. This explains why the cladists consider the protist a paraphyletic group.
Okay first of all, humans did NOT evolve from monkeys or anything like that. So there were NO plants that became dominant as humans evolved. Evolving is for dummies!! :0)
plankton