Staredit Network

I was thinking about the theory of evolution the other day, there is one thing that has always botherd me about evolution. That is the switch from asexual reproduction to sexual reproduction. Although the biodiversity gained from the sharing of two D.N.A. strands is incredibly usefull it seems that acording to the theory of evolution it shouldnt have possibly occured. Yes it helps evolution along but should it even be possible?
the theory of evolution states that changes occur through mutations and genetic sharing over thousands and thousands of years if not millions and millions of years. Ok this works but according to the theory of evolution these gentic traits should only be passed on if they are advantageos to the carryer of the genetic trait. Sexual reproduction in it self is advantageos but the inbetween stages are not. To develop the required organs and mechanisms required for sexual reproduction would have required a lot of genetic changes and a lot of time. Ok you can accept that these are possible and could have occured, but why where the inbetween stages from asexual reproduction to sexual reproduction advantageos.
Until the actual moment that genetic sharing was possible through these mechanisms they would have actually would have been of a disadvantage to the organisms carrying them. They would have been a disadvantage becuase they would require extra energy that could be used in other survival techniques that were instead being spent it creating mechanisms that still wouldnt be helpful for many generations. Evolution says that only organisms with and advantage will survive becuase species will enevitable breed more then could possibly be sustained so those with advantages will more likely survive. So if evolution is completely correct then why did these creatures with the genetic disadvantage of being inbetween asexual and sexual reproduction survive and go on to produce more young which would also in turn have to survive with this disadvantage? if i'm missing something in this then please inform me, but doesnt it seem odd and incongruent?

edit: just so people dont get the wroung idea, i beleive in evolutiona and i think the theory makes a lot of sense, but it's still a thoery with a lot of proof to it's name. I also would like good answer becuase i think evolution is true but there seems to be a few problems with it here and there.

Part of the thing is, evolution isn't perfect.
All a trait needs to survive is for those that have it to be lucky enough to survive.
Something with a disadvantage, such as melanism or albinism may just happen to find an area with lots of food, water, and little chance of being found by predators, and would have thus increased the number of creatures with such genes.

I agree evolution isnt perfect, but when bad genetic traits get through, they are either are usfull in some way like sickle cell where it makes it hard to get another disease (cant rmeber which disease sickle cell prvents) or they are miner and only effect one or two genes. reproduction effects the whole body on a drastic scale and is by no means small genticly.

Addition:
I beleive sickle cell prevents the person from getting malaria.

Long ago, two paramecium were friends. One day, paramecium #1 said "Hey lemme stick this protein into your membrane." They proceeded. Paramecium #2 said "Hey, that feels pretty good, let's do it some more."

They kept on for days until the protein interaction caused a flaw in Paramecium #2's asexual reproduction. #2 blamed it on #1 and tried to get it to stick around and help #2 with this new ordeal.

And you know what Paramecium #1 said? "Wasn't me."

EVOLUTION!!
(Starring David Duchovney and Julianne Moore... Special gay appearance by Chris Tucker)

lmao

i don't think sexual organs developed just like that. it's been awhile since high school science for me, but I think a current belief is that some cells would share genetic material rather than make clones of themselves. I think that as more advanced creatures began to appear, sex organs appeared with them as a means to continue sharing genetic information.

Wow... its tough being serious in here.

RANDOM OMFGWTFLMAOROFLROXXORSUXXORPWNAGE!!!!11!!one!!11!!

I would like to note that simply because it cannot be explained does not mean it must be explained by something else we cannot explain.

Basically, if you don't get it, don't give out conclusions.

you are correct, the origins of sexual reproduction did not begin with organs but rather with mechanisms that allowed the cells to splice their genes then reasmble them when merged with another corrosponding set of strans.that is why i siad mechanism and organs, becuase the mechanisms are what were really being changed (dont want to go to far into the sciences to lose the common person in this thread) but anyway to makes these mechanisms work properlly and with a succesful results would still ahve required inbetween stages where they wouldnt ahve been advantageos.

Dude, I am soooooo glad high schools over for me

slightly off topic?

Nope, no flay rhoim Nice tho

Ok, one thing your missing in the evolution of sexual cells.

Single celled bacterium transfer DNA to one another even today. The DNA transfer does not result in a new organism, but it does help spread out the genetic variance of cells.

Now to answer your question.

Cells that worked together with other cells out performed single cells in gathering resources and coping with the environment. These massive cells would have been better off if they shared their genetic materials, so they could coordinate the facilitation of resourses. I could picture a failed group of cells that would have one cell change one stubstance into another, and the cell next to it would change it back. It would not function as well as a group of cells who shared the same goals.
Anyways, once you have a group of cells that function the same way, they most likely will not function very well alone. They have adapted to the environment of being in close proximity to other cells. The answer to this problem would be to create specialized cells that would not have a problem with leaving the barriers of the cluster. These specialized cell's only function would be to multiply with what resources were given to them.
Now although you might think that one group of cells would do well enough with simply releasing the specialized cells and letting them grow. But since the cells now share the same dna, this would cause a hinderence in the long run. Some virus would simply come along and use them all. There was no better way to diversify the genetic code than to make two of the specialized cells meet. It would have been much harder to have two multicelled organisms to swap genes.
This is based on the fact that sponges (considered to be the most primitave multicelled animal to date) simply release the eggs into the water, where the eggs meet another one and land to make a new sponge.

Sexes really are an evolutionary advantage. You can still choose to be celibate if you want though.

rantent, you completely missed the point of what i was saying. yes what you said is correct genetic varience is a very very great advantage. this has been proven countless amounts of times, but thats not the issue im adressing. the end result is very advantagous, but according to evolution it takes millions of years to get such variance as the ability to reproduce sexually, during this interm millions of years the trait must be advantagous to survive . but sexual reprodcution is only an advantage when it can actually be pulled off, in the millions of years that it would take to develop this trait the development would actually be a hinderence before it wuld be possible to sexually reproduce, this interm time should have been enough to wipe out the chance that sexual reproduction would be possible because if the bearers of this incomplete trait had a disadvantage they should have died out by probablity.

I did hit the point, saying that it was not a hinderence at the time.
What I was saying was that this was not the only thing developing at that point in time. Many good things come with side effects. The sexual reproduction came at the same moment as the multicellular organism, which all in all is much improved at surviving than simple one celled organisms.
This sort of development is seen all through out history, where one major development comes with several others that would not nessisarily be an advantage, but must occur in order for the whole change to work.

When you realize that there are probably many different things changing in an organism, than you can't really say with certainty that any one of them is the cause of hinderence.

I hope I'm being clearer now, I'm tired.

i get it, it makes sense, its highly improbable but sense obviosly we all arent sprouting buds to make clones it might possibly have happend that way. and becuase i see no other argument for how it could have occured then it most likely occured this way. thank you rantent, that was a genionly good point made, that i hadnt thought of. theres irony in it too, we basicly got really really lucky that it ended up that way.

Well thanks.

Do we only evolve for the things we need to survive or just random stuff and we got lucky and here we are, in a world full of balance and life...

Ok, I ask no more discussion until everyone has read this (or enough of it so that you think you actually understand it; I would estimate at least 70% of the page):

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

Failure to do so shows ignorance as you would be arguing without knowning what the topic is about, which is what most of you are doing right now.

I liked Darwin's expression in that picture.

To answer your question. Genetic variance happens randomly. The animals who are better able to survive in the environment will develop better than the ones who develop processes that hinder them. So evolution would include both of those ideas.
We develop randomly, but because of that randomness the better suited animals survive better.

So, it's a coincidence that every animal has like a nose, mouth, ears, eyes in the head, legs (and arms) in the body, and like stuff like that.

Ok Listen up. The problem with you people is your misconception of what sexual reproduction is. It is not inserting a blam into a blam, it is repruduction in which two non-identical strands of DNA are used to produce a non-identical offspring. Bacteria can sexually reproduce in something what is called "conjugation" (they form a tube through which they exchange DNA). And they did not evolve any organs or anything. So I think that fixes one crack in evolution that you didn't realize.

A nose gives a sense of smell, allowing animals to detect food better, and smell predators. A mouth allows an animal to eat. Ears allow an animal to hear predators coming, and hear prey nearby. Eyes on a head allow animals to have sight, letting them see predators/prey and food, and stuff, and on a head that can look in different directions allowing for a bigger field of view.

Legs and arms allow for manipulation of the environment and moving around.

All those features are advantageous, and thus came about via evolution.

How about vocal cords? Thumbs? And, if there was a disease that would wipe out life, would we evolve to be immune to it?

The theory is that a common ancestor(not molester) of several plants/animals/etc. had a trait that was passed on to all subsequent generations. At some point an animal developed a nose, and over time as that animal developed into many different species, all of them retained a nose of some kind.

There are many examples of this. Evolution is fun to study, get a book on it.