Re: Our hair grows continuosly

The problem with continually growing hair, in an evolutionary context.

You don’t ask a question here, so there is nothing for me to answer. 
However, you do seem to be making an argument about the impossibility of 
human evolution. I can respond to that.

You have set up your argument as a logical fallacy of the type that 
Richard Dawkins referred to as “An Appeal to Personal Incredulity.” The 
fallacy is simply stated is that if I can’t understand how something works 
it therefore cannot work. You cannot understand how humans could have 
survived with continually growing hair in a non-technological environment. 
Therefore, humans could not have survived in that environment and 
therefore humans could not have evolved from that original condition. 

Some things you might want to consider:

1. There is no evidence as to when the phenomenon of continually growing 
hair appeared in human evolution. It is certainly possible that long 
growing hair did not appear until after stone tool technologies had been 
invented. If tools came first, then long hair is not a problem and your 
argument falls apart.

2. Hair is rather brittle and tends to fall out, or break. People with 
extremely long hair (with lengths that might be inconvenient in a non-
technological environment) go through a great deal of effort to preserve 
their long hair. Indeed, some level of technology is required before 
people can successfully grow extremely long hair. By its very nature, 
extremely long hair would not stay attached to the body for very long. 
Therefore, it would not be a problem.

3. What would prevent pre-technological people from biting, breaking, or 
pulling their own hair (one strand at a time if necessary) to keep it from 
growing too long? The people may have been pre-technological, but that 
does not mean they were stupid.

4. There are plenty of examples of similarly continually growing 
structures in different animals. Human finger and toe nails grow 
continually, but we can bite or break them to keep their lengths 
manageable (see points 2 & 3). The claws of cats and dogs, horses hooves, 
rodent teeth and bird beaks all grow continually, but natural wear tends 
to keep them from growing too long. There are plenty of examples of these 
type of phenomenon in nature, yet I know of no example where these 
continually growing features threaten the survival of the species. If 
these mechanisms work in other animals why would they not have worked in 
early humans as well?

In short, the fact that human hair grows continuously is biological 
curiosity, but it is not a biological problem. There are plenty of 
mechanisms to explain how humans could have coped with this curiosity 
without having to invoke miraculous or alien intervention.