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Just as the title says. Why do some organs come in pairs, but others come singly? What happens during the development of an embryo that causes two or one organ to develop?
phinds said:The evolution of two eyes seems very reasonable since depth perception is useful for both predator and pray, but I can't think of any reason why two mouths would be all that useful and two sex organs would just be damned confusing.
As to why the embryo develops that way, that just genetics. It's evolution that causes the genetics to be that way.
.Scott said:Similarly, it would be difficult to arrange the plumbing so that two hearts would be better then one.
By "Darwinian experiments", I was referring to the results of evolution. So my citation is you, in the corporal sense.Drakkith said:Got any references for that, Scott?
Apparently worms are a significantly different engineering problem. I'm not surprised.AlephZero said:Hmm... earthworms have ten. Evolution doesn't have follow human logic to work.
.Scott said:By "Darwinian experiments", I was referring to the results of evolution. So my citation is you, in the corporal sense.
.Scott said:But the parts that decide when we're too hot, too cold, or too hungry, or control out sleep or blood pressure have more tightly integrated forms of redundancy.
We could have two spines carrying redundant data - but there would still have to a single decision point in the brain feeding both spines and muscles would have to decide while spine to listen to.
According to the Darwinian experiments, one well-protected spine provides a better pay-off than redundancy.
That was my point, nature did select it out immediately - or quickly enough.DiracPool said:If we were to duplicate our already paired spinal columns, that would confer a measure of signal traffic confusion that would be unworkable. Nature would have selected that out immediately.
For bilateral symmetry as far back as.Scott said:How far back in human evolution would you have to go before you found an opportunity ...
Our kidneys are responsible for filtering waste products from our blood and producing urine. Having two kidneys allows for more efficient filtration and ensures that our bodies can properly eliminate waste products. Additionally, having two kidneys provides a backup in case one kidney is damaged or not functioning properly.
Our lungs are essential for breathing and providing our bodies with oxygen. Having two lungs allows for a larger surface area for gas exchange, allowing for more efficient oxygenation of our blood. Additionally, having two lungs provides a backup in case one lung is damaged or not functioning properly.
Our eyes are responsible for vision, which is an important sense for navigating and understanding our surroundings. Having two eyes allows for depth perception and a wider field of vision, making it easier to detect potential dangers and gather information about our environment.
Our ears are responsible for hearing and balance. Having two ears allows for better localization of sounds and helps with balance and coordination. Additionally, having two ears provides a backup in case one ear is damaged or not functioning properly.
Our ovaries (in females) and testes (in males) are responsible for producing hormones and gametes (eggs and sperm). Having two allows for a higher chance of successful fertilization and reproduction. Additionally, having two provides a backup in case one ovary/testis is damaged or not functioning properly.