Evolution: FALSIFY IT!

^ You got me man, I didn't actually expect anybody to get it, haha. Especially not in such thorough detail. Personally I believe in evolution, and can't see how somebody could -not- believe in it, it's not only been proven before, but can be proven again.

reply to post by BrandonTsia


(you posted almost simultaneously a statement supporting evolution on the "evolution: prove it!" thread, so I was reasonably confident that you already accepted evolution to be highly likely)

I previously posted an attempt to falsify evolution with the insect wing and the irreducible complexity argument (which I then reduced), not because I think irreducible complexity has any real merit, but because I think the Young Earth Creationists that make the argument about other organs - such as the toucan's bill or the woodpecker's brain - aren't trying as hard as they could.

It would be nice if they would try harder to provide actual, workable examples rather than crying "Oh, you are so clearly lacking faith, you sad, childish little atheist" - which is a) a cop-out and b) neither relevent nor true. So thanks for being a substitute evolution-denier.

Well, it seems there are plenty people who still defy the ideas of evolution. Now, whoever disagrees with it, can you please show us why we're wrong? I'd love to actually see if I'm wrong. If I am wrong, and evolution is false, I will accept it. If your attempts to falsify evolution are incorrect, I'll show you.

Wow I can not believe sane and rational or beings of light and faith could see any thing useful out of talking to each other in such a way.

Well you asked to be showed where you were wrong.

Originally posted by madnessinmysoul
Well, it looks like plenty of people on here still disagree with evolution, but I still don't see any good reason for it. Can someone please provide proper justification for not believing in evolution?

Explain why Trichomonas vaginalis, a unicellular eukaryote parasite, has over twice as many genes as humans. More often than not it has been shown that parasitic lifestyle leads to reduction in number of genes.

Originally posted by rhinoceros

Originally posted by madnessinmysoul
Well, it looks like plenty of people on here still disagree with evolution, but I still don't see any good reason for it. Can someone please provide proper justification for not believing in evolution?

Explain why Trichomonas vaginalis, a unicellular eukaryote parasite, has over twice as many genes as humans. More often than not it has been shown that parasitic lifestyle leads to reduction in number of genes.

edit on 6-1-2011 by rhinoceros because: rephrasing

One reason could be that is has to adapt to shifting environments. It could also just be duplications with no significant impact.

Why do you think gene number defies evolution?

Originally posted by Thain Esh Kelch

Originally posted by rhinoceros

Originally posted by madnessinmysoul
Well, it looks like plenty of people on here still disagree with evolution, but I still don't see any good reason for it. Can someone please provide proper justification for not believing in evolution?

Explain why Trichomonas vaginalis, a unicellular eukaryote parasite, has over twice as many genes as humans. More often than not it has been shown that parasitic lifestyle leads to reduction in number of genes.

One reason could be that is has to adapt to shifting environments. It could also just be duplications with no significant impact.
Why do you think gene number defies evolution?

Don't think it has to adapt to shifting environment any more than any other parasite on the planet. It doesn't explain the huge number of genes. In general all obligate parasites experience massive reduction in genome size as many genes become unnecessary and selection favours smaller genomes. Not the case with T. vaginalis thou. Why? Clearly God created this organism as the crown jewel of all life as it defies natural selection

reply to post by rhinoceros


Trends don't equate to constants. And I'm not a particularly well versed person on genetics, but I'm pretty sure that it's mostly non-coding DNA.

I mean, that was a totally serious question, right? I mean, you couldn't have picked...a fern, which has even more DNA instead.

reply to post by Ubeen


I'm just asking for a proper falsification of evolutionary biology. Nothing more.

Originally posted by madnessinmysoul
reply to post by rhinoceros

 

Trends don't equate to constants. And I'm not a particularly well versed person on genetics, but I'm pretty sure that it's mostly non-coding DNA.

I mean, that was a totally serious question, right?

I mean, you couldn't have picked...a fern, which has even more DNA instead.

Its genome is not massive. Some 160 Mpb. However it has a huge number of genes. Maybe almost 100,000 ORFs and at least 30,000 unique protein encoding genes, perhaps as many 60,000. What goes for trends not equating constants. The fact that all the organisms we've studied so far seem to have evolved doesn't imply that all current organisms on the planet are end result of such mechanism? Just a trend..?

reply to post by rhinoceros

Explain why Trichomonas vaginalis, a unicellular eukaryote parasite, has over twice as many genes as humans. More often than not it has been shown that parasitic lifestyle leads to reduction in number of genes.

Very interesting point, and I'm going to answer based solely on conjecture and the results of a very brief googling of the organism. First, I'd like to note that Trichomonas is a single-celled protist, which does change the game rather - the "simplified" parasites tend to be metazoans. In single-celled eukaryotic parasites, such as Trypanosoma and Plasmodium, which are more vulnerable to the immune responses of their mammalian hosts than intestinal helminth parasites, I would expect the adoption of a parasitic lifestyle to be associated with an increase in complexity. Certainly both these genera show patterns of surface-protein expression that would not bring any obvious benefit to free-living protists, and so remain at the top of their game, as it were, when it comes to killing people.

The difference between them and multi-cellular parasites, to my mind, is enormous - for a long-lived, multi-cellular parasite, the body and particularly the intestine represents a buffet of all the nutrients that could possibly be required, and being rather too large to be engulfed by any phagocytes, the only immediate demand made of them is that they reproduce before the chemical attacks of the immune system destroy them.

From the perspective of many single-celled organisms, the body is rather less inviting - it does offer a greater availability of nutrients than many non-living substrates, but finding your way in to that, when you can't build a cyst big enough to get you in through a dietary route, or burrow effectively through the skin, presents immediate challenges. Once that's done, the body has mechanical and chemical means to deter intruders, which are often more worrying for a parasite that can't grab onto something with its scolex. Without a basic nervous system to allow you to identify the best environment to hide from your host's auto-repair system, you'll need to have an in-built mechanism for getting there anyway. Once there, you're still going to have to find a way to avoid detection by your host's considerable armoury, and seeing as acquired immunity in vertebrates is a fairly powerful force, the odds are stacked up against you, so you'll also need to have a way of getting your offspring into a naive host when everything goes tits up, 'scuse my french, in this one.

Most simplification in metazoan parasites, unless I'm mistaken, is largely down to a loss or reduction of digestive tracts, aerobic respiration, and locomotory capabilities, although reproduction and attachment mechanisms can become incredibly complex. In single-celled organisms, digestive tracts are absent, locomotary capabilites would likely become more important (have to get to the right bit of the host), and many would have previously inhabited anaerobic environments.

Finally, although this could just be my memory playing tricks on me, I seem to recall being told that despite morphological simplicity, many parasites have rather larger genomes than their free-living relatives. Certainly Caenorrhabditis elegans a free-living nematode worm, has one of the shortest genomes in the animal kingdom, more simple than many parasitic nematodes, which was why it was one of the first (if not the first) animal to have its genome sequenced to completion.

reply to post by TheWill


I think this is a far better explanation than I could have given. I'm better with the functions of evolution related to selective factors than the harder biology (though I'm trying to educate myself, I have to deal with my University education first and foremost in another field).

Anyway, thanks for the great explanation, I learned a lot.

Originally posted by TheWill
Very interesting point, and I'm going to answer based solely on conjecture and the results of a very brief googling of the organism. First, I'd like to note that Trichomonas is a single-celled protist, which does change the game rather - the "simplified" parasites tend to be metazoans. In single-celled eukaryotic parasites, such as Trypanosoma and Plasmodium, which are more vulnerable to the immune responses of their mammalian hosts than intestinal helminth parasites, I would expect the adoption of a parasitic lifestyle to be associated with an increase in complexity.

You're expecting wrong. For example the smallest bacterial genome discovered so far belongs to Carsonella ruddii, an aphid endosymbiont. It's only some 160 kbp big. The smallest archaeal genome discovered so far likewise belongs to a non free-living species, Nanoarchaeum equitans with some 490 kbp genome. And how about mitochondria in eukarya? Your typical mammal mitochondrium genome codes only 13 proteins! The largest found so far codes 62 proteins, which is nothing in comparison to their free-living sister group, the alphaproteobacteria with genomes that code some 1000s of proteins. If you look for example here it's quite clear that this is what happens with eukaryotes too. Parasites have the smallest genomes. It makes a lot of sense for obligate parasites. They can lose most of their metabolic pathways without any problems. If they're intracellular they can lose very fundamental stuff like eg. tRNA coding genes w/out suffering. Which brings us back to T. vaginalis. Why the huge number of genes? My hypothesis: God created it in his image

reply to post by rhinoceros


(most of the examples you listed are symbionts (EDIT: except possibly N. equitans, which tend not to be persecuted so by immune systems)

As to the wiki page, it is interesting, particularly where it comes to the trypanosomes.

However, an alternative explanation comes from constraints: in terms of genetic constraints, what do we know about Trichomonas free-living relatives? Do they have more, or less? And what are the functions of the genes which have become more or less complex in the parasitic form? In terms of environmental constraints, how does this genome compare to other vaginal parasites?

Also, age of parasitism relationship. Early in parasitism, the genes gained for the reasons that I laid out (which remain valid) would surely dominate, and gene loss, where excess genes do not carry significant costs relative to surviving host defenses, would be greater later on.


Simple number of genes (or rather, as the wiki page points out, number of predicted genes) is not a particularly useful statistic.

As I said, interesting, and please note that I did warn you that my arguments are conjecture.

EDIT: The suggestion that God created a vaginal parasite in His image is novel and very entertaining.


EDIT pt. ii: Also, mitochondrial genomes are generally held at least in part in the nuclear genome, and it's a very OLD relationship. The only genes that one would expect to be left are ones necessary for aerobic respiration and ATP synthesis, since the host cell does everything else for them. They don't have to bother with reproduction or immune-system avoidance, which are issues for parasites.

Not trying to falsify evolution and I am not very well read on the topic, so I figured this would be a decent place to get some questions answered... Can anyone explain to me how the conscious mind and thought were developed... I know the theory of evolution states that simple cells, evolved into complex cells, and then into the millions of different organisms we have to day, or something to that extent.
What I have trouble with is how; from these cells, an organism can evoke into beings with thoughts and senses. How did the cells know what to do, by mistake, or mutation? How did they have the know how to create new organisms and continue to live?
Another thought is the elements. Do elements change or evolve? Or is everything made up of the same number of fixed elements on this earth. Just a thought, how did the elements bond to create trees, or people, or anything. If it was from cells and other organisms how did the organisms/cells know how to use the elements?

Maybe these are ill-asked questions and maybe they don't make sense, but if you could do your best to help me understand a little bit better it'd be much appreciated. Once again I'm not trying to disprove anything, but before I can make my mind up on what I believe concerning evolution I felt it necessary to ask some questions.
Thank you!

Where did the matter come from? Everything needs to have been created and, as of yet, there is no theory explaining that.

reply to post by Techy

Originally posted by Techy
Where did the matter come from?

How does this relate to evolution? Evolution is a theory which explains biodiversity. It is a theory of population genetics, nothing more.

Everything needs to have been created and, as of yet, there is no theory explaining that.

I'm sorry, but since when does everything need to have been created? I've never actually seen anything be created. I've seen things have their shape, composition, etc change...but I've never actually seen anything be created.

Why is it that matter cannot simply exist?

reply to post by Techy


Evolution is not meant to describe how matter was created. It explains the evolution of the species.

reply to post by madnessinmysoul


But evolution couldn't happen unless something was actually there in the first place - creationism explains that, it explains how the matter was made and put there. Evolution couldn't happen without there being matter in the first place.

I apologize though, I suppose that is more straying into the topic of the creation of the universe.

But on the topic of evolution, why? Why create predators to kill other creatures? Why don't all species live off plants? And why are there millions of different types of species, even though a lot of them work the same (there are lots of different types of ants, but most of them do the same thing)? I'm sorry if I seem ignorant, I don't really know much about evolution :/