How did sexual reproduction come to be (from an evolutionary standpoint)?

reply to post by sk0rpi0n

I see you haven’t been reading the links people have posted. Why am I not surprised?

Originally posted by Astyanax
reply to post by sk0rpi0n

 

I see you haven’t been reading the links people have posted. Why am I not surprised?

Mainly because the content of those links usually revolve around the concept of "it exists, so it must have evolved", much like your previous post (which has been edited, of course) Real smooth move there.
Good thing that I quoted it.

Originally posted by sk0rpi0n

I'd like to know how exactly complimenting male and female cells developed and then went on to be able to produce offspring... after a gestation period.

Im talking about origins of the mechanism of sexual reproduction.

So was I. Fungi and plants, like us, have evolved two sexes that both create cells of transeferable genetic material that contribute to their off-spring, on a gene, match for match basis and, the mutation that was, self-incompatibility, derives, to us, from those successful mutations that we share with plants and fungi. We are more closely related to Fungi than plants. Some Fungi can reproduce sexually, all asexually. Mammals can only reproduce sexually, therefore we were also reproducing asexually at some point in our family tree before it became more successful to us, to develop purely sexual reproduction and the genetic distinction of being mammals. The more lifeforms that are genetically mapped, the clearer this will become.

I am presuming though that you even understand 'Non-sexual' reproduction. Which clearly...

Originally posted by sk0rpi0n
Not about basic stuff about genitals being no different from flower parts.

...you do not.

It would be much easier to answer the 'how' if you could be more specific as to which aspect you have trouble understanding. And often the 'how' is the same as the 'why'...

Organisms that reproduce through asexual reproduction tend to grow in number exponentially. However, because they rely on mutation for variations in their DNA, all members of the species have similar vulnerabilities. Organisms that reproduce sexually yield a smaller number of offspring, but the large amount of variation in their genes makes them less susceptible to disease.

en.wikipedia.org...

How? Because in order to create the diversity and robustness necessary to exist in a hostile and changing environment, we had to, otherwise we wouldn't be here. The more complex we become as organisms, the greater the complexity of problems that we face in our environment in order to survive. This though is more than biological, it exists at the chemical level too. And in mathematics it can be proven or at least explained. Hence why, in my opinion, evolution can exist alongside the equally theoretical concept of intelligent design. On earth we have much more than a fossil record to examine our genetic record, if anything all the fossil record tells us is what was unsuccessful. What failed. We have a vast living record, all the many lifeforms that have evolved alongside us and been equally successful in surviving the trials and tribulations of life on Earth, serve to demonstrate why and how sexual reproduction developed. We share genetic similarities/traits/codes with every living thing on this planet. Once you get to the plant level, it can be much more easily demonstrated too.

So, there are precursors for the development of sexual reproduction at the genetic level. Which aspect of sexual reproduction is it that you want to know the 'how' for, and I will see if I can find the explanation for you? If you want to know though how the first cells became distinctly male and female, then the answer, I am afraid, will be plant based. The 'why' is the one that is harder to answer, potentionally impossible, the how can easily be demonstrated and proven.

reply to post by uva3021

Asking "how" something occurred is such an absurd question in respects to evolution, again for reasons banal and obvious.

"Evey Hammond: Who are you?
V: Who?...Who is but the form following the function of what and what I am is a man in a mask."

To play on words a little from a scene in V for vendetta on asking obvious questions, on who the man in the mask is that is standing right in front of you.

Asking how to the untold number of millennial of evolution concerning sexual reproduction is just as nonsensical. I to don't think "how" is the right thing to ask either. Because "how" is just is the form following the function of "what" and "why".

And the "what" is observable right to our faces today if looked at, and the "why" can also be understood to certain degrees that we can grasp from the "what" that is right in our faces and sight.

So if you know "what" it is today. You can deduct to get a semblance at the understanding of "why" it is. And when you can more fully grasp the "why" it is, then you can begin to answer or deduce on the how.

Wouldn't it be better asked, "What is sexual reproduction, and why it came to be?"

Instead of "How did sexual reproduction come to be?" How it happened is jumping ahead of yourself really, and in this case by billions of years. Because you can't know HOW it happened which is the unknown in this equation, the unknown past. Without knowing the WHAT it is, which is the known, the present which is observable, the thing right in your face and sight, the thing you can see and touch and measure. And the WHY is the explanation between those two. The bridge between present and past, the known and unknown, the WHAT leads to the WHY, the WHY is the gap filler, the bridge to the HOW? which is a question.

So what the hell is the point of sexual reproduction as it is in our world today?... Is a question that needs to be looked at deeper before even beginning to go on to.... How did sexual reproduction come to be?

Basically how did penis and vagina come into being?

I once thought that too. It's a hard question. Really, we don't know.

What's worse... how did orgasm come into being?

They are one of the mysteries of life. That why some people are digging. Saying that god did it isn't going to satisfy some people.

I, personally, believe in ID. But we have to be honest. We JUST do not know.

Originally posted by sk0rpi0n
When the question of how sexual reproduction evolved, all we have are various hypotheses and theories... in other words "guesses". Even if scientists managed reached some sort of a consensus on as to which hypothesis explains the evolution of sex, it simply means that they all agreed on one speculation.

Looks like my suspicions were correct, which would explain why you didn't reply to my post. You're misrepresenting what a scientific theory is either intentionally, in which case you're just intellectually dishonest, or unintentionally, in which case you're just uneducated. If it's the latter, I can help:

From the US National Academy of Sciences:

The formal scientific definition of theory is quite different from the everyday meaning of the word. It refers to a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence. Many scientific theories are so well established that no new evidence is likely to alter them substantially. For example, no new evidence will demonstrate that the Earth does not orbit around the sun (heliocentric theory), or that living things are not made of cells (cell theory), that matter is not composed of atoms, or that the surface of the Earth is not divided into solid plates that have moved over geological timescales (the theory of plate tectonics). One of the most useful properties of scientific theories is that they can be used to make predictions about natural events or phenomena that have not yet been observed.

And from the American Association for the Advancement of Sciences:

A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world. The theory of biological evolution is more than "just a theory." It is as factual an explanation of the universe as the atomic theory of matter or the germ theory of disease. Our understanding of gravity is still a work in progress. But the phenomenon of gravity, like evolution, is an accepted fact.

You're other bit of misrepresentation is that scientists are just agreeing on speculation. You're either misrepresenting this intentionally, in which case you're again being intellectually dishonest, or you're doing it unintentionally, in which case you just don't have a good understanding about how science works. They're going to reach a consensus based on the body of evidence, not sheer speculation.

Let us all put aside the popular theories and hypotheses put forward by evolutionary scientists (who themselves don't know how it happened) and think about this for OURSELVES...

This can be read as: "Let us all ignore all of the research in area of the origin of sexual reproduction that has occurred and engage in pure speculation."

In order for sex to have evolved perfectly...
1. Compatible male and female cells had to have developed independently to perfection.
2. Then, the mechanism of conception (gene mixing etc) had to have also developed right.
3. Then, the process of gestation also had to have developed right.
4. And then sexual reproduction had to have branched out to both the animal kingdom and the plant kingdom, (or did sexual reproduction arise more than once in the evolutionary path??? Yeah, right.)

This amounts to an argument against evolution based on irreducible complexity, which has been solidly refuted each and every time it's been presented. No biological system has yet been shown that had to have developed all of its parts simultaneously to function. Further, your second example existed long before sexual reproduction and may actually have been one of the first evolutionary mechanisms - it's called horizontal gene transfer, look it up.

I hope you all realize that the implications of an error at any of these given junctions would have been the end of sexual evolution. And since evolution teaches that it all occurred without any overseeing intelligence, we are supposed to believe that sex went through all these vital steps, to develop to perfection.

You're ignoring parallel lines of evolution, invoking intelligent design (which is just creationism v2.0, even though you claim in another post to not be a creationist), and invoking irreducible complexity again. But by all means, keep going. You read like a textbook from the Discovery Institute.

Now that is a grand claim, but has little to nothing to back it up. And no, hypotheses by scientists is simply not the same as "hardcore evidence" such as observing organism undergo mutations in laboratories.

Except that the "grand claim" as you present it is a strawman. Another typical tactic by a typical creationist.

reply to post by sk0rpi0n
From each point in the process of appropriating the modern form of reproduction, which takes many many forms, a random mutation happened that incurred selective advantages. Hence, as long as the drumsticks are there, the drummer can start to drum.

Again, its beyond obvious the "how" when dealing with evolution. We know all about the "how", and have known all about the "how" ever since Weismman disclosed the distinction between soma cells and gametes affirming Mendel's laws over 120 years ago.

To say such and such evolved because it is here is not apropos to "God did it." We understand how evolution works, how organisms development, the mutation rate of genes, etc...

The studies are to explain sex allocation ratios, the maintenance of sex, the twofold cost of sex, among many other devices that are apparent in the evolution of sex.

Orgasms are a response to the female's ability to retain sperm, and is highly correlated with level of attraction between MHC genes of the two engaged in coitus. Additionally, the intensity of sexual stimulation from a mate is a solid diagnosis of ones genes. Any genes that encourages sex will likely spread in the gene pool anyway.

Originally posted by sk0rpi0n

Originally posted by Astyanax
reply to post by sk0rpi0n

 

I see you haven’t been reading the links people have posted. Why am I not surprised?

Mainly because the content of those links usually revolve around the concept of "it exists, so it must have evolved", much like your previous post (which has been edited, of course) Real smooth move there.
Good thing that I quoted it.

edit on 26-3-2011 by sk0rpi0n because: (no reason given)

No, science says they have several HYPOTHESES, as in, THEY DON'T HAVE A DEFINITE ANSWER. That's been mentioned several times already, but you continue to say "so, tell me, how did it happen?"...kinda silly

Originally posted by Deaf Alien
I, personally, believe in ID. But we have to be honest. We JUST do not know.

This.....

.... is the truth. We just do not know. Im glad at least ONE member of ATS gets it.

reply to post by sk0rpi0n

The content of those links usually revolve around the concept of "it exists, so it must have evolved", much like your previous post (which has been edited, of course) Real smooth move there. Good thing that I quoted it.

Yes, well caught. Congratulations.

If a biological trait exists, it must have evolved. I have no problems owning up to such a statement. It is merely the truth, and only people who refuse the evidence of science with respect to evolution will contest it.

So ask: why did it evolve? For the same reason fins, eyes and immune systems evolved. They evolved because they, and their immediate precursors, conferred a selective advantage on their owners. In the case of fins, eyes, immune systems, downward-pointing nostrils in upright bipeds, etc., the advantage is rather obvious. In the case of sexual reproduction, it is not so obvious. But just because we cannot definitively answer the question why it evolved does not mean it did not. To state as much would be rather stupid, as I’m sure you agree.

The Wikipedia link you were fed first of all explains how the various hypotheses regarding the origin of sexual reproduction have been tested and are being tested. Clearly you failed to read this, or to take on board the implications of it. iterationzero has already dealt sufficiently with the reasons why you did not.

Testing is what distinguishes a hypothesis from mere speculation. In the absence of direct empirical observation the best we can do is evaluate hypotheses against whatever evidence does exist. This is true not just in respect of the origins of sexual reproduction but that of all biological traits; indeed, it is true of all scientific propositions. That does not invalidate the theory of evolution, which has plenty of direct evidence to substantiate it.

A more intelligent question to ask (as you belatedly realized) might be how did sexual reproduction evolve. The answer is: very easily.

• Life most probably evolved in a liquid medium.
  
  
• Originally, it was unicellular, a primitive ancestor of modern bacteria.
  
  
• Bacteria exchange genetic information simply by releasing it into the surrounding medium and taking it up from that medium. Early cells did this too (they could hardly help doing it). Thus the principle of outcrossing was already well established before eukaryotes made their appearance.
  
  
• Genetic exchange through a surrounding liquid medium remains highly popular to this day as a means of reproduction; apart from bacteria, it is also how many kinds of fish and other aquatic fauna exchange genetic information. However, fish have evolved specialized organs (gonads) to produce specially designed cells (sperm and eggs, also known as gametes) that unite to form zygotes. This is sexual reproduction as we know it, and it has several obvious selective advantages over the strategy of simply strewing nucleic acid about the place. The evolution of gonads and gametes from their precursors is well documented; no doubt some kind person will furnish you with the relevant links.
  
  
• Thus the evolution of sex is merely the specialization of certain organs in multicellular organisms for the purpose of manufacturing genetic material and ejecting it into the surrounding medium, where it combines to form a zygote.
  
  
• The later refinement of internal fertilization and gestation, as practised by mammals and some fish, and partially by birds and reptiles, is also well understood in terms of how it evolved.

The question ‘how did sex evolve?’ is thus as easily answered than the question of why it did. But I don’t believe you’re really interested in finding out the answers; you were simply trying to set a trap for evil evolutionists. Well, the trap is sprung, and you yourself are its victim. So it goes.

Originally posted by MrXYZ
No, science says they have several HYPOTHESES, as in, THEY DON'T HAVE A DEFINITE ANSWER. That's been mentioned several times already, but you continue to say "so, tell me, how did it happen?"...kinda silly

Well, in that other thread about Noah, you were cornering biblical creationists, asking for evidence of events written in an ancient document (which you know is not exactly what one could call a scientific document). Yet, when it comes to defending your own views (which you say is within the domain of "science") you seem to say "oh, theres really no definite answer" but still continue to maintain that it evolved. Nice!

Well, since thats not going to change, at least tell me, does "THEY DON'T HAVE A DEFINITE ANSWER" also apply to the question of evolution as a whole? Or is it strictly reserved only for questions like "how did X, Y or Z come to be", questions that merely attempts to test the validity of ToE?
Im only asking because ToE seems to be held as as a confirmed fact, yet "they dont have a definite answer" for the very mechanism (sex) on which ToE itself depends on to a very large extent.

Now, isn't that silly.

You have drawn a conclusion (evolution occured) before having evidence to back up the very mechanism that evolution works on. Again the old "we dont know, but evolutiondidit"

reply to post by sk0rpi0n


Well, as mentioned in the other thread, it doesn't really matter. For example, no matter how it happened, chance mutation, DNA defect, outside influences...it still wouldn't invalidate the theory of evolution. Humans would still share a common ancestor with today's apes, the mouse and elephant would also still share a common ancestor, and birds would have evolved from reptiles as the theory claims.

An Axiom is a statement accepted as true without proof. A theorem is a statement proved to be true.

Some people seriously get the two confused....

i.e. 1 is an infinite number, how many "think" 1 = finite?

Originally posted by Serafine
An Axiom is a statement accepted as true without proof. A theorem is a statement proved to be true.

Some people seriously get the two confused....

i.e. 1 is an infinite number, how many "think" 1 = finite?

edit on 2011/3/29 by Serafine because: addition

Like I said, they aren't accepting anything without proof...which is why they classify it as HYPOTHESES. Keep on ignoring that fact, but it makes you look silly

Originally posted by sk0rpi0n
Well, in that other thread about Noah, you were cornering biblical creationists, asking for evidence of events written in an ancient document (which you know is not exactly what one could call a scientific document). Yet, when it comes to defending your own views (which you say is within the domain of "science") you seem to say "oh, theres really no definite answer" but still continue to maintain that it evolved. Nice!

Well, since thats not going to change, at least tell me, does "THEY DON'T HAVE A DEFINITE ANSWER" also apply to the question of evolution as a whole? Or is it strictly reserved only for questions like "how did X, Y or Z come to be", questions that merely attempts to test the validity of ToE?
Im only asking because ToE seems to be held as as a confirmed fact, yet "they dont have a definite answer" for the very mechanism (sex) on which ToE itself depends on to a very large extent.

Now, isn't that silly.

You have drawn a conclusion (evolution occured) before having evidence to back up the very mechanism that evolution works on. Again the old "we dont know, but evolutiondidit"

As mentioned before, but obviously ignored, you're confusing "don't have a definite answer" and "have absolutely no evidence". The current hypotheses for the evolution of sexual reproduction are based on evidence, not pure conjecture. More evidence needs to be acquired to determine which of those hypothetical models, or combination of hypothetical models, is the most likely.

Also keep in mind that evolution may rely, to some degree, on sexual reproduction but it doesn't matter how sexual reproduction came to exist, just that it does exist. Your argument is similar to those who try and conflate abiogenesis and evolution by arguing that, because we don't know for a fact how life came to be, the theory of evolution cannot be correct. The theory of evolution doesn't care how life got here, it's only concerned with what it does once it exists.

Seriously, the strawman arguments are getting old.

Genesis 1:1 In the beginning God created the heavens and the earth.



Intelligent Design - DNA
An excellent example of intelligent design is the DNA molecule. Since its discovery by James Watson and Francis Crick in 1953, evolutionists have faced an insurmountable hurdle. Anyone who truly investigates the mystery of the DNA molecule -- this incredible micro, digital, error-correcting, redundant, self duplicating, information storage and retrieval system, with its own inherent language convention, that has the potential to develop any organism from raw biological material -- understands that life is the result of Intelligent Design. In light of recent discoveries such as the DNA molecule, the absurdity of the evolution argument is readily apparent when its basic formula is compared with that of the creation model of origins. Creation states that matter + energy + information = incredibly complex life. Evolution states that matter + energy + random chance = incredibly complex life. The theory of evolution is merely a religion that serves to discredit the Intelligent Designer Himself.

reply to post by Faith2011


And once again, you copy/paste something from Godlikeproductions or a similar site without quoting the source. And what's worse, it's blatantly obvious that what you posted is pseudo-science and nothing more. Hell, they claim DNA is "digital"

PS: Save yourself the bible quotes, they're not objective evidence. They're only proof of what people believed 2000 years ago...as our knowledge of the real world increased, some of those ideas are now obviously considered complete nonsense. Unless you're an ignorant fundamentalists who closes his eyes from reality simply because it goes against their irrational belief based on 2000 year old beliefs

reply to post by MrXYZ


Psalm 14:1 says, “The fool has said in his heart, There is no God.” Atheists may be brilliant scholars or academics. They may be wonderful inventors, surgeons, or scientists. But if they say there is no God they are declaring themselves fools in spiritual matters. This is why atheism is sometimes called the fool's philosophy.

The Apostle Paul pointed out in Romans 2:15 that God has written intuitive knowledge of His law in our human conscience. In a wonderful passage in Romans 1:20 he says, “For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse.”

There is abundant evidence of God's handiwork written on our conscience and in nature all around us, and there is no excuse for not recognizing God's work in this.

Originally posted by Faith2011
reply to post by MrXYZ

 

Psalm 14:1 says, “The fool has said in his heart, There is no God.” Atheists may be brilliant scholars or academics. They may be wonderful inventors, surgeons, or scientists. But if they say there is no God they are declaring themselves fools in spiritual matters. This is why atheism is sometimes called the fool's philosophy.

The Apostle Paul pointed out in Romans 2:15 that God has written intuitive knowledge of His law in our human conscience. In a wonderful passage in Romans 1:20 he says, “For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse.”

There is abundant evidence of God's handiwork written on our conscience and in nature all around us, and there is no excuse for not recognizing God's work in this.

You're entire belief is based on a book that only contains what people believed to be true 2000 years ago. You might wanna catch up on what science discovered since the, as the alternative maks you look silly

But fine, I'll humour you...what's your OBJECTIVE EVIDENCE for god's existence?

reply to post by MrXYZ



The probability of life origination at random is so utterly minuscule as to make it absurd, it becomes sensible to think that the favorable properties of physics, on which life depends, are in every respect deliberate. It is, therefore almost inevitable that our own measure of intelligence must reflect higher intelligence . . . even to the limit of God." - Sir Fred Hoyle, British mathematician and astrophysicist, an atheist for much of his life, until he finally admitted the truth.

Lots of people have reasons for what they believe, but when those reasons are refuted--when they're taken away or weakened by other evidence--do they still stand on their point of view, or are they willing to adjust their view based on the evidence that comes in?

THE HEAVENS declare the glory of God; and the firmament shows and proclaims His handiwork.

Day after day pours forth speech, and night after night shows forth knowledge.

There is no speech nor spoken word [from the stars]; their voice is not heard.

Yet their voice [in evidence] goes out through all the earth, their sayings to the end of the world. Of the heavens has God made a tent for the sun.Psalm 19:1-4

But people who aren't spiritual can't receive these truths from God's Spirit. It all sounds foolish to them and they can't understand it, for only those who are spiritual can understand what the Spirit means. 1 Corinthians 2:14