Humans are small, compared to the universe. Compared to the Earth, humans are about 1 millionth of the whole planet. From this point of view, humans are not very significant.
But SIZE is not a good measure of IMPORTANCE.
The Earth may be a speck in a vast universe, but it is a very important speck! And humans are no less important in a world of vast numbers of living things.
Where do we get our significance from?
The only reliable place is from ourside ourselves - from the mighty God who created us. For more information on this, read Genesis chapters 1-11 and Psalm 139
Because God is intelligent, we can expect to find that the design of our body is also intelligent.
Just as the designer of any complex machine must use planning, intelligence and wisdom to make their machine, God has also used these things to make us.