alien birth

[flynniv]

Just to nitpick, most species of sharks do not lay eggs either, but rather have live births.

I think that even then, the sharks are birthed from eggs, just that the eggs aren't 'laid' but carried inside the mother shark until they hatch (tho I could be wrong).

Can I ask what the definition is of "intelligent" life? Ravens use tools - heck, some of them use us! I remember a thing about some crows or ravens (in England, I believe) that were dropping seeds or nuts onto a crosswalk - the crosswalk, mind you, not the middle of the road - and waiting for the light to change. The cars would drive over them and then the birds would wait for the light to change again before they went down to pick through their now-opened lunch.

Sure, the crows of the world may not have a civilization but that's some pretty high-functioning brain power, and I can definitely imagine an alien that evolved from something similar.

[Jens]

Ifcourse cows do not lay eggs, but they cant read nor write.

I really don't understand. Why are you bringing up cows in a negative context? I thought your point was that egg-layers are less intelligent. . .

[BigDon]

The main thing an organism has to figure out first, before live birth can insue, is a genetic method to determine gender.

That just came out in a recent paper.

Pythons give live birth and are very "basic" intellect-wise. Possums give live birth and qualify as pea-turkey stupid.*

I've seen possums walk face first into flower pots. Only 60% the cranial capacity of a rodent the same size. That's reptile stupid.

Gomar, the main thing you should do in my opinion, is get thee to wiki and look up the various forms of vivipary that creatures of Earth use, with the two main variations. Even hunted them down for you.:

http://en.wikipedia.org/wiki/Vivipary

http://en.wikipedia.org/wiki/Oviparity

http://en.wikipedia.org/wiki/Ovovivipary



*As explained by my parents, who were both farm raised in rural Oregon, certain pea vines were neurologically toxic to turkeys, who eat them anyway and suffer brain damage as a result.

Domestic turkeys are rather bird-brained to begin with, so retarded, brain damaged turkeys I imagine are just sad to behold.

[primummobile]

why have male and female...to me thats rather odd and not efficient. a species really only needs one type to produce copies of itself.

It's not very efficient if you are only considering the number of offspring. But sexual reproduction does improve the fitness of the progeny, especially over many generations.

Sexual reproduction is also better than asexual reproduction at repairing any genetic damage to that line. Diploids (organisms having two sets of chromosomes) have a much better chance of eliminating damaged genes because chances are that only one of the two genes will be damaged. An asexually reproducing organism passes all genes to its offspring, damaged or not. The only way that damage is going to be repaired if for that damaged gene to undergo another mutation down the line. That is far less likely to happen than the method of gene repair employed by sexually reproducing organisms.

Almost every multicellular organism on the planet reproduces sexually. That alone is evidence of the usefullness of sexual reproduction.

What could or should happen on alien worlds is all just conjecture. I wouldn't go so far as to say that something resembling sexual reproduction hasn't evolved elsewhere in the universe. But I don't think that we can really do anything more than guess, and since we only have one confirmed sample to work with, those guesses are going to be pretty wild and have very little basis in reality.

[BigDon]

Hi Prim, welcome aboard.

Basically one gender isn't enough and three is too complicated.

[BigDon]

Now in science fiction, one of the races in the Planet of Adventure series was the Dirdir. A bipedal, cheetah sized space faring race of felinoids. They had 23 genders, any combination of three being needed to produce offspring. (And if I recall correctly seven combinations were forbidden due to religeous reasons.)

The Dirdir also openly enjoyed hunting human children for sport. Legally purchased ones mind you, and only on their hunting reserves. They aren't savages afterall and humans produce so many of them. Six to ten year olds especially. At that age they are old enough to understand what was happening and therefore "audibly stimulate the Dirdir's hunting instincts" when they finally close in on them, while still being small enough to take down with just teeth and claws.

Yeah, the main character didn't think very highly of them.

He thought even less of the humans who mimicked them.

[Ara Pacis]

When you say gender, do you mean genetic sex identification or do you mean social role identification?