What determines gestation period in mammals?

[IndianaJones]

Is the human gestation period short or long compared to other mammals?

Thanks.

[The Velveteen Ocelot]

1. It's as long as it needs to be.

About 62 days to build a kitten; about two years to build a baby elephant.

[TZ]

2. and don't forget our friend the platypus...

That lays eggs!!!
Gestation is related to how much care a baby needs to have at birth..ie a horses gestation period is eleven months because the baby (for predation avoidance issues) needs to be able to walk and run within a day.
Size of course is also an issue whales and elephants obviously have longer gestation periods because of that.

[Deja Q]

3. At 350 degrees, one minute per pound?

[TZ]

4. answer me a question, HT..

Is that picture on your sig line actually you in a lab situation?:D

[QueenOfCalifornia]

5. The smaller the eyeball

the shorter the gestation period.

[Dr. Strange]

6. Isn't that one of the ten commandments?

[swag]

7. The Lord God

[IndianaJones]

9. amen. nt.

[Raejeanowl]

8. Appropriate For Our Size

I do remember reading that it has everything to do with the species size. Horses, elephants, etc., comparably longer than man. Rabbits, cats, pigs, much shorter.

[muriel_volestrangler]

10. That's a very rough guide

But not infallible. A cow has a gestation period of 9 months, and a calf weighs about 10 times as much as a new born human. A guinea pig has about the same gestation period as a dog.

Humans have a pretty long period, for their size. Perhaps the complexity of brain development has something to do with that. Humans are pretty helpless when they're born, compared with most animals - but it's thought there's a trade-off - a baby's brain couldn't be any bigger for a bipedal woman to give birth - as it is, giving birth is far more dangerous for a woman than it is for most animals.

[achtung_circus]

11. 9 months

for cow or for Countess.

[EstimatedProphet]

12. There's two main factors

1) size of the animal - mice have a very short gestation, elephants have a very long one

2) precocial young (able to take care of themselves at birth) vs. altricial (unable to take care of themselves). Precocial animals typically have a longer gestation period.

[IndianaJones]

13. do you a background in biology? nt.

[EstimatedProphet]

19. Yes

I am a biologist. I am known as EstimatedProphet, the biolgist. I biologize.

[La Lioness Priyanka]

14. the lord god vishnu decided this child. who are you to question it?

[IndianaJones]

16. I'm trying to get input from the non-believers here. Be quiet. nt.

[La Lioness Priyanka]

17. the lord god shiva will strike you down child. then the goddess kali will chop your remains.

[texas1928]

15. The stork brings the babies.

what are you talking about? :shrug:

[hunter]

18. BTW, the "done cooking" signal comes from the baby, not from the mom.

A woman I used to work with delivered her own baby at home, and not by choice, it was entirely unexpected. She dialed 911 but her son was born before the paramedics got there.

Her husband had left for work, and her mom was arriving to stay with them a few hours later, but nobody had expected anything would happen in that short time. She said good-bye to her husband, fell back to sleep, and when she woke up she was having a baby.

She always teased her son that he always picked the very most inconvenient time to do any big project, and when he did it was always a huge rush.