Why was it unsurprising that van Leeuwenhoek detected bacteria and protozoa?

image result for describe the various types of gene mutationsghr.nlm.nih.gov

the types of mutations include: missense mutation: this type of mutation is a change in one dna base pair that results in the substitution of one amino acid for another in the protein made by a gene. nonsense mutation: a nonsense mutation is also a change in one dna base pair.

explanation:

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?