Do sea shells all spiral in the same direction?
Question
I noticed that all the sea shells with Spiral growth patterns (I have not yet seen otherwise) all grow in the same direction. What would the reason for this be? What forms or creates sea shells to "grow"?
Answer
Diana - It sounds like you've got a right-handed shell there which is called a dextral shell. You do get other shells which are left-handed and they're more sinister called the sinistral shells, but there's no real obvious reason why you get more right-handed shells right now than you do get left-handed shells.
Many people think that if you have all shells within a certain population, which are the same "handedness", it's much easier for them to mate with each other.
因此,如果你得到一把up that's left-handed, it's going to be difficult for the right-handed one to mate with it.
But looking back over paleontological records, you do get periods when more left-handed shells appear and then you get periods when more right-handed shells appear, and it just seems to be something that fluctuates and changes with time.
At the moment, we're getting mostly right-handed shells...
Comments
Do sea shells spiral the same direction?
What sparked this question for me was when i was learning about the coriolis effect on the water in our oceans and weather patterns. I began to wonder if this had an effect on animals and specifically ones that have a spiraled shells if it was maybe the reason why they grow one way or another?
sea shell spiral
do you think it has anything to do with "global warming" ... like sea turtles are producing mostly female offspring?
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