Evolution: Man and woman

[Genecks]

Here's an idea:

 

What if men evolved from women?

What if the reason children become easily attached to women is because women are the less dominant type of human? In other words, something within the psychobiology of the child tells it to attach itself to a woman?

 

What is the reason?

[AzurePhoenix]

I won't try to delve into psychology of mother-offsrping relationships, but biologically the male sex is far older than the human species. "Males" and the sexual reproduction they're around for have been present throughout the history of cordates, and long predates them. And they're not actually a dominant form so much as a useful means for shuffling genes about. Male behaviors among humans and other primates are simply the behavioral role they've fallen into, in my opinion due to their expendability compared to the value of females. Whip-tail lizards did away with males entirely.

[SkepticLance]

Sorry.

Both are you are wrong. The two genders co-evolved. Neither is older than the other. We only need to look at representatives of older versions of sex in the more 'primitive' life forms still represented today. In terms of evolution, the two genders are equal.

 

Babies imprint on the first person to give them total attention. This is normally the mother. When a woman gives birth, during labour there is a surge of oxytocin (also called the love hormone) into her bloodstream. This is not something I am making up. It is measurable, and has been measured.

Reference : New Scientist 29 April 2006. The sudden surge of oxytocin gnerates a dramatic emotional effect, 'imprinting' the woman on her baby. Generating powerful love. After that, it is hard to keep Mum away from baby.

 

However, there is another imprinting, on the father. He also comes to love baby, though in a less dramatic way. If, for any reason, mother cannot be primary care giver, Dad takes over that role, and babies 'imprint' onto their father. I know personally several examples where a child gives first emotional call to its father, and only secondary to Mum.

[AzurePhoenix]

Sorry.

Both are you are wrong. The two genders co-evolved. Neither is older than the other. We only need to look at representatives of older versions of sex in the more 'primitive' life forms still represented today. In terms of evolution' date=' the two genders are equal.[/quote'] I'm sorry if you confused what I said, but I never said that one evolved from the other, just pointed out that humans have always been male and female, and that males were not dominant to the other. I just didn't feel the need to delve into the female part in the scheme because of the largely male direction Geneck's post led me to consider. His/her post seemed to me more concerned with male/female relationships as applied to humans rather than their ultimate origins, from the standpoint of evolution.

[Genecks]

I'm considering human origin. I'm thinking somehow men mutated from women and the female form of a human has been around longer than the male version. Perhaps because women were around longer, it would be natural for a child to be with a mother instead of a male. The reason for this is because men are a somewhat mutated form in mind and body, and the pre-evolutionary mindset of a child tells it to stay with the woman.

[Moonquake]

I'm considering human origin. I'm thinking somehow men mutated from women and the female form of a human has been around longer than the male version. Perhaps because women were around longer, it would be natural for a child to be with a mother instead of a male. The reason for this is because men are a somewhat mutated form in mind and body, and the pre-evolutionary mindset of a child tells it to stay with the woman.

How do you think humans reproduced before this?

The species we evolved from had males and females, why would men have just dissapeared for a while?

also http://www.scienceforums.net/forums/showthread.php?t=18767

[Edtharan]

I'm considering human origin. I'm thinking somehow men mutated from women and the female form of a human has been around longer than the male version.

If you are considdering human origin (and this isn't just a joke post) then you will need to look at fossils. Human fossis and Hominid fossis have amle and female all the way back. If you follow the evolution then those earilyer forms had male and female, and so on. This goes back to when all life was single celled organisms.

 

Back then these single celled organisms just used asexual methods of reproduction. Neither Male or Female existed.

 

Once these organisms evolved to use sexual reproduction (they are not exactly sure how this occured but they doo have some theories) both Male and Female had to exists. You could not have a Male without a Female or a Female without a Male (how could they reproduce). In the case of the Whip Tailed Lizards, although the curent population came from females, can they be considdered females at all now as they are using Asexual reproduction, not Sexual reproduction? There is no Male/Female in asexual reproduction.

 

One theory on how Sexual reproduction evolved is that some organisms would share their genes with each other. This would be done equally in both directions. However if one organism managed to unequally share their genes with the other (ie A would give their genes to B, but B would not give their genes to A), this would create a situation where one A was male and the other was female. This allowed a successful A to distribute its genes to many offspring and so would become dominant. This would, however only occure if the B's would accept that material (too much of A's gene in the gene pool and it would have no one to reproduce with). So a balance would establish its self.

 

This genetic stability would have allowed an explosion of different species for occure and also allow more complexity in thoes organisms.

 

Als the organisms became more complex and multicellular then they would have had to evolve ways to transporting the genetic material from one to another. This would have been sperm, and would have originated from the organisms that donated genetic material as they could cover more females this way.

 

The recipent cell could now be called the egg and would be in the female. This cell would have had an advantage in being less mobile as it would need to store the energy for growth in it and so need to be large.

 

This is only one way that evolution could have produced males and females, there are others, so it is not a matter of that we don't know any processes of evolution that could cause male and femalt to evolve, it is that we don't know which of the many posable way it took on Earth (or it might have even been several ways and at several different times and places too).

[Genecks]

So from what many of you are saying, my question is invalid because men did not evolve from women; in other words, men and women came about at the exact same time.

[SkepticLance]

Based on what we know of the requirement for genetic variation in order for organisms to adapt to environmental changes (such as a new disease), whip tail lizards are clearly on the road to extinction.

 

Sexual reproduction is necessary.

[FreeThinker]

Of course they both evolved at the same time, how else would either one have offspring?

[AzurePhoenix]

Based on what we know of the requirement for genetic variation in order for organisms to adapt to environmental changes (such as a new disease)' date=' whip tail lizards are clearly on the road to extinction.

 

Sexual reproduction is necessary.[/quote'] While sexual reproduction certainly has more than it's share of boons, it's by no means necessary. Sticking with the Whip-tail lizard example, their particular native desert environment is especially slow to change, and pathogenic dangers are markedly lower than those of wetter climes. While certainly vulnerable to a rapid shifts in the environment, and presumably any new disease that might pop-up, their parthenogenic method of reproduction gives them the advantage of doubling their reproductive potential by only producing daughters. As it stands, evolution can occur in such a species, simply due to mutation, it just happens to occur at a much slower rate and lacks the added booster of sexual selection.

 

Like any other trait, asexual reproduction has both its ups and its downs, though certainly fewer ups than its sexual counterpart < insert dirty joke here >

 

So from what many of you are saying, my question is invalid because men did not evolve from women; in other words, men and women came about at the exact same time.

yes, from humans tracing back to much earlier than even our earliest spinal-corded ancestors, males and females have existed as separate sexes.

[8600]

If males had somehow "evolved" from females then humanity must have been an asexually reproducing species originally. (In which case the term "female" would have been irrelevant anyway as there'd be only one gender.)

 

We know that humanity has never been an asexual species, just like all the other primate species that have ever existed.

 

Therefore, males couldn't have evolved from females.

[SkepticLance]

Azure Phoenix.

On the question of how necessary is sexual reproduction.

 

Bacteria can survive without it. At least some varieties, that do not undergo gene transfer.

 

Higher animals cannot, at least long term. Short term, asexual reproduction brings great benefits. It massively reduces genetic variability, though. As you commented, as long as the environment stays constant, that does not matter. However, no environment stays perpetually constant. And do not forget the biotic part of the environment. All you need is a new virus entering the habitat, and ....

[Dark Photon]

people are not more easily attached to thier mother. the baby will be attached to whoever invests time on them at an early age

[Dr. Dalek]

people are not more easily attached to thier mother. the baby will be attached to whoever invests time on them at an early age

 

The attachment might change to. A child could spend their early years looking up to their mother and then become more attatched to their father when older.

[AzurePhoenix]

Higher animals cannot, at least long term. Short term, asexual reproduction brings great benefits. It massively reduces genetic variability, though. As you commented, as long as the environment stays constant, that does not matter. However, no environment stays perpetually constant. And do not forget the biotic part of the environment. All you need is a new virus entering the habitat, and ....

I fully agree, I was simply pointing out that it (sexual reproduction) is not neccesary, and that parthenogenic reproduction does allow change to happen, ableit at a far slower rate. It is not the best method, and will likely fail in the long-term, but for now, it suits them very well. And in the whip-tail's case, failure isn't inevitable if the system changes, simply far more likely than for sexual species.