Do you believe alien's or external life exist outside of our world? why?

This is not a question we can answer, this is a question only you can answer because it is asking for your personal belief on wether alien's exist outside of earth or not.

Explanation:

I do believe that there could be alien life out there, but our radio signals just aren't powerful enough to reach the further parts of space.

Explanation:

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands