Scientists notice structural similarities between fossils of a land animal and an aquatic organism. they know the similarities are not a result of the two organisms having to adapt to similar environments. what can they attribute the structural similarities to?

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .

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?