Darwin, Explain this! again

Philosophy Forums Science, Technology, and Math
1

i know that my previous two attempts may have been the result of a little short sightedness, but i have a pretty simple paradox for you.

back in the day, a creature was born who, unlike every other creature who had ever lived, was randomly born with the ability to sexually procreate.

who did he have sex with? and if he was both asexual and sexual, and didnt immediately end his genetic line as soon as he died, why would this trait be naturally selected?

the reason why sexual reproduction is beneficial is because it allows for variety in many important areas that benefit from variety. when this guy had first obtained the dna for sexual reproduction, and then made clones of himself asexually who could then have sex with eachother for the first time in history, he had one genetic code. his clones had one genetic code. they combined two identical codes, which is not a very good way to create variety.

is asexual reproduction more difficult than sexual? that would explain it. and i suppose it could have stayed around by pure luck until the offspring with the trait did eventually develop variety after at least a few years and thousands of reproductions.

but thats not really the question that made me come back here. when you are born with a new genetic trait, and your parents dont have it, and your instincts have not yet been calibrated to force you to think about it without their help, what motivates the first couple to have sex? what could possibly make them realize that they have this completely unknown ability to do something that nobody has ever done before? did they just bump into eachother through the course of a normal life and their dna mixed together by accident? is that the ONLY way that anybody ever had sex until the instinct motivating us all to do it randomly mutated thousands or millions of generations later?

does the instinct to have sex or any complex behavior evolve right exactly alongside the ability to do the behavior?

and this doesnt just go for sex, its any complicated behavior that requires complicated instincts to accomplish. who would ever think that chunks of other animals are supposed to go into your face unless instinct or your parents told you. domesticated dogs and cats sure dont. they somehow know to kill, but they never saw anyone eat anything before that wasnt in a convenient bowl or plate, so they just leave it there, not realizing there is any connection between it and his crunchy brown balls.

so if dogs and cats need a parent to show them how to eat, who was the first one to show the first person who ever ate? the chicken or the egg? i guess it was a more complicated set of instincts that allowed the first guy to eat of his own volition as well as hunt. and then later on, the genes that allow a baby without parents to know how to eat were discarded in species who were able to watch and learn from their parents.

im not trying to prove intelligent design, so dont talk about that. im just raising questions that ive never heard answered.

2

The behaviours mentioned come from very primitive ancestors. Single celled organisms didn’t exactly procreate in the way we do, genetic material passed between cells by chance. This became very advantageous for multi celled critters and was retained during evolution.

Same for eating, (I believe) that larger protozoa ate smaller cells by absorbing them whole and digesting them. The behaviour was not evolved later (when it would have been harder) it was retained. Sadly I am not a biologist and cannot give the detail I would like (for instance I think the protozoa would need a symbiotic relationship with a smaller cell rather than evolve the required enzymes)

3

Piece of cake to explain, and I ain’t even a biologist.
First of all, there are plenty of organisms still in existence that are both sexual and asexual. Second of all, mutation occurs in both methods of procreation, usually caused by interference from the environment. My guess is that sexual organisms evolved out of viruses–viruses are basically little proto-cells (they’re much simpler than other single-celled organisms) that procreate by inserting their genetic code into other cells, where it takes over and destroys the host cell. Perhaps a cell mutated just enough that the virus could not destroy it and instead merged genetic material. Just a guess at any rate–like i said, I’m no biologist.

As to how the new “abilities” are used, well, you’re anthropomorphising these critters more than you should be. With simple creatures like the early single-cells, the genes didn’t produce abilities that could lay dormant until “discovered” by the cell; if a new ability evolved, it was put into practice immediately, and if it didn’t work, the cell died. Who knows what kind of factors were involved, but given the massive age of the earth, almost anything is possible.

4

Hello.

Being a student I am very fresh in this topic.

okay, so say…plants, they can be asexual or sexual (in this case, “sexual” is between two plants). well the oragaisms you metioned in the orginal post must have been asexual until there came a mutataded spieses with only one sexual organ. you only need a male and a female part to have sex. so I guess it is possable for a sexual organism and an asexual organism to produce offspring with the same mutation as the parent. Androgynous is very primative. as for sex being instinct. I think the chemicals testostrone and estergen(sp?) might be responceable for the sexual instinct. chemicals are very powerful over how we act. such as a chemical produced by female octopuses that when they give birth they stop eating and starve themselfs to death. Adrenline and endofines(sp?) have very powerfull affects on use too.

well them is my thoughts…
-Guy

5

Yeah, the first sexual organisms were likely both male and female as some worms are today, and therefor completely capable of handling themselves. And of course as soon as you had two of them, there you go sex could start happening. Eventually for effeciency sake, organisms developed haveing only one set of sex organs.

For the second part, it’s not beneficial to the organism to rely on sex. However, it is beneificial to the gene. The gene gets to be paired up with many different sets of genes, and in this way, increase it’s chance of survival. For more info, read Richard Dawkins- The selfish gene.

6

Congratulation!
You just proved the logic in evolution.
The example is a little bit off but the idea works.
Evolution is progression by combination.

7

I think evolution (for the most part) is a valid theory, but his paradox does have a good point. Evolution as a general theory (in its current form) does not account very solidly for certain specific biological events, such as the origin of life on earth. I forget who, but somebody wrote a best-selling book called “Darwin’s Black Box” outlining the biological holes in evolutionary theory. Doubtlessly it was best-selling in part because of the creationists and intelligent-design-ists who wanted some validation, but one of my friends has been reading and discussing it with me, and the bits I’m gleaned from it have been very compelling.

 It's a good theory, it's just still in the oven.
8

The theory of the sexes which seems most sensible is the evolution of isogametes. These isogametes most likely had differences in size, natural selection began to favour large gametes because this allowed the organism a headstart in life(started out with more resources, a larger food supply). This then in turn allowed for selfish gametes to flurish, natural selection then favouring the other extreme, small gametes. Small gametes could then take advantage of the larger gametes. The smaller they were the more mobile, and the easier they could penetrate the larger sex cell. Thus the distinction between male, and female is usually based on the size of the germ cells.

Btw Ermogasm you are highly misinformed,I would suggest some different reading. Possibly Dawkins, or Gould. The theory of evolution does account for the origin of life on earth, and researchers have been able to mimmick the initial stages of life in labs, using simple elements, such as water, amonia, and some sort of energy sorce, such as electricity, and uv light. They can basically create a kind of primordial soup, they can in effect create life.

9

In fact modern theory is a T.O.E of biology. Its a complete theory, only the Aesthetics remain, such as creating accurate phylogeney charts for certain species. Its an amazing theory, and the final draft is in.

10

whoa rounder no they did not create life.

they created amino acids with mini lightning like 50 years ago. and i guess since then theyve made more complex proteins and what not. but theyve been trying to make molecules and even cells that look like and act like life. but i imagine it would be all over the news if they did. i remember seeing something in national geographic a couple months ago about some big experiments that were just getting started.

11

No, the theory of evolution does not explain the origin of life.

Only the origin of species; hence the name of Darwin’s first book.

Too many people believe that Darwinism explains the origin of life, and then find holes. They then think that they have discredited evolution.

Not so.

(It is classical approach: misquote or misrepresent your opponent and then show the contradictions or impossibilities. Used often, but unfair.)

12

Yeah okay, I got a little ahead of myself. Through stimulating methane, ammonia, hydrogen, and water, they were able to produce amino acids, “the building blocks of life”. Since evolution occurs over such a vast time period, I personally do not find it deterring that they have not yet created molecules, or even cells. I think the conclusion of the 1952 experiments show that complexity which eventually forms “life” arives from simple elements.

[edit] If you have any information on those experiments I would be interested.

Darwin’s theory was hardly fully realised in his time. Darwin didn’t dream of taking on the origins of life. I hate to play the yes, and no game, but FFS yes! natural selection does explain the origins of life. Simple elements formed organic compounds, which then formed molecules, cells…you know the rest :wink:

13

Well, we’ll have to agree to disagree, then!