So what I understand is, evolution is a mere mistake in the replication of DNA and this change is sometimes good and sometimes bad.
And the other day, in our biology class, we were told the functioning of the lungs and how the RBCs fetch the O2 from the alveoli and dump the CO2 out.
And I also know a little bit about some complicated processes in the body like, how the digestive system works, how the muscle cells switch to anaerobic mode when we run out of O2 causing cramps, how the cells make ATPs in the mitochondrea.
And 1 more notable thing- the amount of complicatedness and all the neural networks in brain.
My question is- how can evolution(a mere mistake in copying a strand of DNA) make such a complicated machine, like our body. There are SO many organs, all working in collaboration to make the body work. And all of those organs are doing SO many things.
I know that this is a result of 3.8 billion years of evolution...but still... how can even a million "mistakes" make a body which is so well deisgned?
ALSO was the whitening of the polar bears a mistake too? Then what are the chances of such a mistake occuring in the replication of DNA? If it was evolution then why don't birds become the colour of the sky?