2006-08-15 02:23:35 · 24 answers · asked by Anonymous in Science & Mathematics ➔ Biology
We have two nostrils because all mammals have bilateral symmetry. Same reason you have two eyes, ears, arms, etc.
2006-08-15 02:29:43 · answer #1 · answered by Anonymous · 3⤊ 0⤋
Humans have two nostrils because that's the way God made man. However, you may need the second one when the first is stopped up. Maybe so you can take turns picking them. That way one doesn't get warn out to fast. I do believe that we can live with one nostril, but I don't want to try.
2006-08-15 02:31:13 · answer #2 · answered by Here's your answer or questi 2 · 0⤊ 0⤋
It's one of the any reduncancies built into the human body.
However you only ever breathe out of one nostril at a time. Whichever nostril is clearer is the one that passes air. When one becomes congested even marginally you use the other one.
2006-08-15 02:30:14 · answer #3 · answered by cirestan 6 · 0⤊ 0⤋
Because in evolution we branched off a LONG time ago from the earliest vertebrates like the hagfish, which only had one median naris. Here is a picture of a hagfish:
http://oceanexplorer.noaa.gov/explorations/lewis_clark01/logs/jul08/media/r609hagfish_532.jpg
Eventually something like a hagfish evolved into a sea creature with two external nares. And I don't think it was until the crocodile or some ancestor of the crocodile that animals developed the two internal nares which allows us to eat and breathe simultaneously.
We're way too far removed and evolved from the one naris model, but I'd say that if we somehow removed one of our naris then we could still breathe through the other.
2006-08-15 04:44:16 · answer #4 · answered by Stephanie S 6 · 0⤊ 0⤋
It's because when your body is formed as an embryo, you're joined up at the centreline and develop roughly symetrically. After the ball stage (or blastocyst), we progress to being a simple tube with one end being the mouth, then a groove forms one one side of the tube which ends up developing into your spine and central nervous system. Thereafter everything else develops more or less symetrically. But this explains why you have only one mouth.
2006-08-15 06:42:03 · answer #5 · answered by Andrew 3 · 0⤊ 0⤋
if you think about it, not only two nostrils, the human body has lots of things in duplicate, just work out how many, but only doctors will know some of them inside the body which we know little about and its function and purpose
2006-08-15 05:03:09 · answer #6 · answered by srracvuee 7 · 0⤊ 0⤋
in the course of evolution, reproduction was achieved by cell division. At some point a cell failed to divide properly so had in a lot of cases 2 of everything. These were very successful and survived. We are effectively deformities, but have two eyes, arms, and other things, and this works better hence our success in evolution
2006-08-15 02:32:38 · answer #7 · answered by ArskElvis 3 · 0⤊ 0⤋
Two reasons come to mind: One balance in looks. THe3 second is stereo smell. Two eyes give you distance to what you are seeing, two ears give you location of sound. Two nostrils give you direction of scent.
2006-08-15 02:29:58 · answer #8 · answered by maccrimmon 2 · 0⤊ 0⤋
If u can live with one lung u certainly can with one nostril.
2006-08-15 02:29:02 · answer #9 · answered by Wolverine 3 · 0⤊ 0⤋
It annoys me when one of my nostrils is blocked up, it feels too weird!
But if you want to, then go for it!
2006-08-15 02:29:21 · answer #10 · answered by Anonymous · 0⤊ 0⤋