How does evolution theory explain the sex differentiation?

Edit: see post #2 if this one is confusing.

I don't know if this has this been discussed here and I also don't know how
exactly to formulate this question correctly. Anyway..


In my understanding, according to evolution theory, we are all evolved from
simpler life form. But how does sex differentiation between male and female
developed? Why today in almost all kind of species (except hermaphrodite
or asexual type), for every male species there is the female species?


Let say the evolution path was like this:

species A ---> species B ----> ................. ----> human

Each species consist of male and female. In which stage did the male and
female differentiation developed?

Assuming the male exist earlier before the female, was it like this (scenario 1):


----------------------------------------------------------------------

Note: you can skip this first scenario if this is confusing.

male A ---> female A, male B (male of species B evolved from male of species A; female of species A also evolved from male of species A)

male B ---> female B, male C

male C ---> female C, male D

etc until:

male XYZ ---> human male ---> human female

----------------------------------------------------------------------

Or was it like this (scenario 2):

male A ---> male B ---> male C ----> ................... human male
female A ---> female B ---> female C ----> ........... human female

:shrug:

 

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My question could be also expressed in another way. Let say human came from ape
and the first human was male.

Then where does the female human came from? Was it evolve from male human, or from
female ape?

Let say female human evolve from male human. If I kill all female human,
will eventually female human evolve from male human? If so, how can that happen,
while to create the next male generation (and hence giving enough time for the
evolution to happen) that next male generation should be born first, and that would be
impossible without the presence of the female one?

Or was the first human asexual? hermaphrodite?

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What about all other species?
Does it all follow the SAME pattern? How come? Coincidental??

 

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Human were never asexual or hermaphordite, in fact human ancestors went duel sexed ohh ~500 million years ago when they evolved just beyond worms. Duel sex or gonochorism is more stable then hermaphordism when mate selection can happen, the theory goes like this:

1. A male only mutant appears in a population of hermaphorditic organism by random mutation.
2. The male is able to spreed it genes faster then the hermaphordites because it waste less energy making progeny by only providing genes, the male variant soon outnumbers the hermaphordite varient
3. A lack of breedable partners for the males makes the hermaphrodites variant competitive viable again.
4. A female mutant appears and is more competitive then the hermaphrodite variant because it does not waste energy trying to be a male.
5. Eventually the hermaphrodite variant dies off.

Mathematica models simulate evolving populations show this to be true, that hermaphroditism is usually an unstable state in multiple cellular organism with mate selection, that these population usually fall into the more stable state of gonochorism.

 

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I am not quite sure what you are asking. Before there was sexual reproduction there were of course no males or females.

 

Before I reply to post #4, I will firstly reply to this post (post #5).

Sorry for the confusion.

As I understand, evolution is a slow process, it took very long time until one
new species formed from another simpler form. Human species, for example,
who is said to be firstly appear in Africa about 200,000 years ago, till now
hasn't changed into a different species. Perhaps it doesn't evolve anymore.
Anyway according to evolution theory, it was evolved from something else; it
wasn't created by invisible hands.

There are at least 1.5 million species of living organism (that so far been named,
not to count the one that hasn't been named). In almost all kind of species,
there is a male and female couple. If one species evolved from another, how
come all these species has its pair? Coincidental?

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That's why I asked, how was the chain of evolution which correspond to the
formation of the opposite sex. And as the example, I asked about the human
species.

We are consist of male and female, and we are evolved from something simpler.
As human male is simpler than human female (e.g. male can't produce baby), I
assume the human male existed first before the human female. But where
does the human female came from? If it was evolved from the male, I would
say it is impossible. Why?

Let say it took 1000 generation until one male can changed into female. But
the 2nd generation of male CAN'T be existed unless the 1st generation of male
can reproduce. The 3rd generation CAN'T be existed unless the 2nd one can
reproduce, etc. To create the next generation, there should be the opposite
sex in the first place. Right? Unless it was hermaphrodite.

And so I asked whether the first male were hermaphrodite.

If not, then the first female human must be evolved NOT from the male human,
but from the same previous ancestor (let say ape, the female one).

If that is true, then the chain of evolution was like this:

ALL male: species A ---> species B ----> species C ----> ............. ----> human male species

ALL female: species A ---> species B ----> species C ----> ............. ----> human female species

That doesn't make sense to me either as the female of each species more
closely resemble to its male species. Female human are much more alike with
male human then female ape, right? Female cat much more alike with male
cat then with other female species, right? And so on.

So, what do you think? :shrug:

 

I understand step 1. Lets stop at step 2 first:

2. The male is able to spreed it genes faster then the hermaphordites because it waste less energy making progeny by only providing genes, the male variant soon outnumbers the hermaphordite varient

What do you mean by spread its genes? Spread where to? There was no
female one at this stage. When there is no female one, the male one can't
spread its genes :shrug:

 

Your scenario is only possible to happens if:

* The male and the female mutant appears at the same time
* The male and the female mutant appears at the same or nearby place (so that they can meet and reproduce).

And this happens to all others 1.5 million species?

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Another question:

* how long does it take to form one species from another until it created all pairs of 1.5 million different species?
* with the age of earth, is that process possible?

I mean, is there any finding that explain about it??

 

lol Theres your error, There where no sudden males or no sudden females, it was a very long gradual process.
Look at it this way,
There was a single celled organism that reproduced itself and over time became a two celled organism, etc.. eventually becoming a multi celled organism, as it adapted to it's environment, it was more efficient for it's survival, so it adapted to two sexes( this being over a very long time) from this change came every two sex species on this planet.

lol, Well with that kind of mistake, you should be.
It didn't happen to all the species individually, all the species came from the original one.

 

I don't think so. In the whole kingdom of 1.8 million species, each species are
distinct. You can't miss one species with another. One species also can also
reproduce with each other in the same species. So how does each species
formed into pairs (male and female) in all 1.8 million species??

My question still also remain: where does the female human came from?
From male human or from female ancestor? Both doesn't make sense to me
(I explained the reason in the previous post).

So, from the whole existing 1.8 millions species, where does each opposite
sex came from? (p.s: age of earth is only around 4.5 billion years old). What
is the time scale of evolution of each species? Oldest human appears nearly
200,000 years ago. Until now it hasn't evolved into another species. What
about the cats? dogs? etc? They are still the same as well, don't they?

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My point is, you said (and all other evolutionist always said) that it changes
gradually, in a very very long time.

Let say species A evolved gradually until it becomes something new after
100,000 years (there is 1.8 million distinct species). How can it evolve
without the presence of its opposite sex? How can its next generation with its
slight change existed without being born? Did its opposite sex came from itself
first? I don't think so. Female human can't evolved from male human, unless the
male human able to give birth to a new (female) human. I think it goes the same
for all other 1.8 million species.

 

You're not thinking about this the right way inzomnia. You expect some kind of sudden change which completely changes a species into another, making them unable to reproduce. It doesn't work like that. It's many small changes over a long time building on each other.

Think of two isolated groups of mice, both the same species. One evolves on an island completely cut off from the rest. Over millions of years both groups evolve differently, small changes building on each other. Eventually a mouse from group A can't reproduce anymore with a mouse from group B, but both groups can still reproduce within their own groups. At that point we say the mice have split into new species. There's no one change that suddenly creates a new species of mouse, it's a long gradual process.

 

That doesn't answer my question yet. Where does the opposite sex of each
species come from?

 

There is about 1.8 million of species out there, and each has its pairs (opposite sex).
How does evolution theory explain this? Can you give me a scenario?

 

It does answer your question. Forget everything you think you know about evolution and read it again. I can't help you understand the process if you're unwilling to let go of the wrong assumptions you've made about how it works.

 

No it doesnt. No all species have both sexes. Again.. everything has being explained to you.. you simply are not understanding.

 

I am here to learn. So what is your answer to my question?

I did mention previously, there is an exception, such as in hermaphrodite or
asexual type. Those are exception. If you feel this is significant, can you
give me the number of the exception?

 

Look, Xelios, if you are able to explain me in a clear and logical way about how
does sex differentiation exist in evolution, I am willing to reconsider my opinion.

 

You're here to learn something you've previously learned wrong. That requires you to forget what you learned wrong, which you're not willing to do. You're holding onto it and consequently what we're telling you seems wrong to you. You can't learn anything if you keep doing that.

I'll make one more go through it.

Think of two isolated groups of mice, Group A and Group B, both the same species. Group A evolves on an island, comletely cut off from Group B. Over millions of years both groups evolve differently, small changes building on each other. Both males and females evolve together. Each time a new generation is produced the changes (if any) are present in BOTH, male and female, of that new generation. No single change is big enough to prevent the new generation from mating with other members of its group (this is the important part you're not getting), and if it is this new generation simply can't reproduce and dies out. The change dies with it.

Eventually (after millions of years) a mouse from group A can't reproduce anymore with a mouse from group B, but both groups can still reproduce within their own groups. At that point we say the mice have split into new species. There's no one change that suddenly creates a new species of mouse, it's a long gradual process.

 

inzommia:
( very appropriate name by the way. )

I'm sorry your just not getting it, you should return to class, you need evolution basic 101.
Here are a few sites that will educate you.

http://www.youtube.com/user/potholer54
http://www.youtube.com/profile_videos?user=potholer54&p=r

http://members.cox.net/sbcogan/evo-kids.html
http://www.leaderu.com/orgs/probe/docs/cr-evol.html
http://www.pbs.org/wgbh/evolution/humans/index.html
http://www.pbs.org/wgbh/nova/link/evolution.html#
http://www.talkorigins.org/

Once you better understand evolution, then you might return and ask questions,( but I don't think you will need too) until then I'd stay of evolution if I was you.

 

Hundreds and hundreds of thousands. Bacteria, virii, fungi and all other forms of life. You did do biology at school?