Disclaimer #1: I didn't know where else to post this to get a Christian perspective.
Disclaimer #2: I know that we can't truly and literally understand why God created these things in us.
I've got to get some gallbladder testing done because it's causing me some discomfort. It may or may not have to be removed. As most people are aware, we can live without it. That got me thinking about other things such as the appendix (which is especially useless and heinous, as it does literally nothing but can take your life) and tonsils. Things that are mostly useless and pointless but can cause severe problems. Why? Why even create them?
Maybe this got answered, but just in case:
Gallbladder:
"Its primary function is to store and concentrate bile, a yellow-brown digestive enzyme produced by the liver. The gallbladder is part of the biliary tract. The gallbladder serves as a reservoir for bile while it's not being used for digestion."
But, yes, you can live without it! Don't panic. You'll be ok.
But what about something more widely thought perhaps useless (the popular notion), the Appendix?
Appendix:
"One theory is that the appendix acts as a storehouse for good bacteria, “rebooting” the digestive system after diarrheal illnesses. Other experts believe the appendix is just a useless remnant from our evolutionary past."
So....
not so clear it's useless. Having good bacteria restored to the intestine after one of the more severe (and life threatening types) of diarrheal illness could save a person's life very often we could surmise -- such as when a person is very greatly weakened by a serious intestinal illness.
Then...small differences in how soon they can recover could be life or death for them!
It may be that many tens or hundreds of millions lived, survived the aftermath of, serious intestinal infections only because they were able to recover quickly enough after because of the appendix. It's possible. So....I would
not assume it is useless. (But, again, if yours is taken out, don't panic. Believe in God and follow Christ, and you'll be fine)
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(note on tangential topic of evolution: God as creator of
all that is, also created chemistry, physics, etc., and all that flow from them....)