No. You fail to understand that your links say that there is no clear answer. First sentence: "The evolution of sexual reproduction is described by several competing scientific hypotheses."
What this says is that there are several non-compatible theories, no clear answer how it might have happened.
Does it ever actually say "non-compatible" or are you misinterpreting "competing"?
A population of Chlorella vulgaris (a single-celled algae) over the course of a weekend obtained a mutation to the genes that transcribe for ligase proteins; due to environmental forcing (IE an infestation of predatory paramecium) the population became fixated with the mutation (IE all members of the population that survived the weekend was the ones with the ligase mutations). This was due to the fact that the mutated ligase protein failed to allow the sister cells to fully break away. This resulted in a colonial form that was too big for the paramecium to swallow.
Wait, they know the mutation? I've seen
the paper that describes the appearance of multicellularity under predation pressure, I don't think it says anything about the genetic basis, though. If you know a study that does, that would be awesome!
As in separation between male and female... didn't know how else to say it.
Ah. "Having separate sexes"? I dunno.
It is true however that scientist look to them and many other species with no clear gender to try and understand why there's a separation in the first place.
I've met people who have done work on plants that can be hermaphrodites or "gendered" within the same population, or hermaphrodites with different levels of investment in their male and female functions. I seem to recall that figuring out why can be a giant headache

... news to me... but then I haven't really been looking into it for a while so I'm a bit out of the loop on that one.
I'm not entirely sure about the history of the idea, but I think
Ruiz-Trillo et al. (1999) may have been one of the earliest papers to place flatworms proper deep among other protostome phyla. As far as I'm aware, large-scale molecular studies fairly consistently relate the beasties to
lophotrochozoans/spiralians (
terminology is a bit confused), although they are notoriously fast-evolving and therefore hard to place exactly.
(Sorry for the infodump. I <3 animal phylogeny.)
Didn't chordates come before vertebrates and are considered to be animals that possess a single nerve chord generally running the length of their body?
Close

To be pedantically precise: vertebrates are a subgroup of chordates (so yes, chordates did come before vertebrates).
Chordates are defined (among other things) by a single nerve chord that is (1) dorsal (
i.e. above the gut) and (2) hollow inside. (
Here's a really nice figure featuring chick embryos from Gilbert's Developmental Biology. The hollowness is a lot more obvious in vertebrate embryos than adults...)
(Though as far as I'm concerned, chordates are defined by their shared ancestry. The dorsal nerve tube just happens to be one of the conspicuous manifestations of said ancestry

)
*DERP* You're right... they're not chordates... not even close. I was just completely mistaken on that one!
's all right. All brains eat beans sometimes!
Reed Frogs and Wrinkled Frogs do this. That's all I know... so yeah, it's more common in fish.
Cool stuff. I learn something every day...
This attitude really annoys me. Evolutionists so often try to stifle debate about the topic by ridiculing those who don't believe in it, as if the theory is proven.
I must echo CabVet here:
Evolutionary biologists don't ridicule people that criticize evolution. They ridicule people that reject evolution without even knowing what it is.
Come, demonstrate an actual understanding of evolution. Show me that you know where the field stands, what questions are
actually debated. By all means, present your
educated objections. But if your objections are on the level of "but mutations can't generate new information", then for the love of God, go away and learn what mutations and information are.
(Or, heck, you don't even need to go away. There's a fair number of people right here with a decent education about evolution and the willingness to share said education.)
I'm an evolutionary biologist by official training. I happen to like physics, though, and every now and then I'll read a popular book about relativity, or quantum mechanics, or string theory (yikes!) or whatever. You might see me discussing physics, or even arguing about physics, with physicists, but you'll
not see me tell them that their well-established theories are Wrong.
Even if I thought that, I wouldn't have the understanding required to make a meaningful criticism. If I had doubts about, say, general relativity - the right course for me would be to go and
ask whether I'd missed something. Maybe I'm onto something, but chances are that I simply haven't heard about the information that solves my problem.
The bottom line is recognise the level of your expertise/ignorance before you go into a debate. It helps if you
do have an intimate knowledge of a field - any field. Look back on how much you've learned about that area over the years, and it will give you an idea of how much you have yet to learn about
other things.
If you don't, you'll go around telling experts they are wrong about their areas of expertise, and then being surprised/insulted when they don't take you seriously.
(Apologies if that sounded a bit ranty.)
OP, there are many serious flaws in evolutionary theory, one major one being how gradual mutations could account for complex biological systems.
There is, in fact, a variety of ways in which they could, one being accidentally duplicating parts and tweaking the now redundant part. (
A small-scale but thoroughly dissected example.) The origin of biological complexity is more of an exciting research area than a serious flaw.
Also, I think speaking of "gradual mutations" is a red herring. There are many kinds of mutations, some of them small and some of them large, some of them with small effects and some of them with large ones (a small mutation and a mutation of small effect are NOT the same!).
But importantly, the consequences of mutations can be, er,
complex. Maybe a whole genome duplication doesn't immediately change much, but it provides thousands of extra genes with far reduced selective constraint.
Perhaps a mutation gains a foothold completely by accident, or by selection on one effect, but together with a
later mutation ends up creating something new.* Or maybe
two species get together and turn into a single, more complex organism.
*IIRC citrate utilisation in the long-term
E. coli experiment evolved in this way. The ability to use a new protein to infect their hosts in
these viruses definitely arose after four mutations that in themselves only benefited the original infection process came together, and simulations with digital organisms keep popping out complex features
arising on the back of originally neutral or harmful mutations.