Naked Science Forum

On the Lighter Side => That CAN'T be true! => Topic started by: Ortelio Teo Gibson on 20/12/2016 09:38:22

Title: Why are babies born with reproductive organs they don't use?
Post by: Ortelio Teo Gibson on 20/12/2016 09:38:22
Ortelio Teo Gibson  asked the Naked Scientists:
   
My son was born just a few weeks ago and it got me to thinking...Why are babies born with reproductive organs if they're not put to use until puberty???

I'd greatly appreciate an answer.
Thanks,

Teo
Nagaoka, Niigata, Japan

What do you think?
Title: Re: Why are babies born with reproductive organs they don't use?
Post by: tkadm30 on 20/03/2017 10:47:36
Reproductive organs are essential for urination...

Title: Re: Why are babies born with reproductive organs they don't use?
Post by: alancalverd on 20/03/2017 17:55:37
The characteristic of mammals is that all are born in pretty much the shape of adults. The same is true of birds, fish, and indeed almost everything except insects and parasites. So the naive answer is "because we are mammals, not insects". Mammals generally seem to reach sexual maturity at about one eighth to one tenth of their healthy life span, and humans aren't far off the mean.
Title: Re: Why are babies born with reproductive organs they don't use?
Post by: Kryptid on 20/03/2017 20:42:24
Reproductive organs are essential for urination...
Not the gonads.

As to the OP, I'll give two possible reasons:

(1) It's easier to go ahead and develop those organs while the embryo is already in the process of developing other organs than it is to develop them "from scratch" when you reach puberty.

(2) It's a quirk of evolution that just happened to be kept because it worked.
Title: Re: Why are babies born with reproductive organs they don't use?
Post by: Bored chemist on 20/03/2017 21:17:18
Because it's better to have them and not need them, than the other way round.
Title: Re: Why are babies born with reproductive organs they don't use?
Post by: Tomassci on 16/06/2017 16:10:54
Devloping gonads in puberty can be risk. And energy insufficient.
Title: Re: Why are babies born with reproductive organs they don't use?
Post by: evan_au on 17/06/2017 13:04:30
Some fish species change sex during their life, for example at a certain age, or if the senior member of that sex dies. In these species of fish, sexual organs at hatching is not necessarily the same as at death.

In humans, sex is determined by the X & Y chromosomes. So sex is effectively determined at time of fertilization. Sex determination starts to kick in at around 7 weeks, and sex is usually evident by 12 weeks.
- I understand that girls are born with a full set of eggs that she will have available as an adult. This could have the advantage of minimizing mutations between generations.
- Males use a very different strategy: they start producing sperm at puberty, and the progenitor stem cells keep dividing throughout life, which builds up more mutations as men get older.

See: https://en.wikipedia.org/wiki/Sexual_differentiation_in_humans#Sex_determination