Thread: Let's discuss evolution from a scientific perspective -not for Creationist, anti-scientific argument

Originally Posted by Darkmatters

Steph, yes, I am familiar with the way embryos seem to cycle through the stages of evolution, beginning as a single cell in a liquid environment, then emerging to begin breathing air and crawl on all 4s until they can rise to 2 legs (and like you said of course, gills etc). I ran across that in a Sagan book somewhere. It serves as a very literal illustration of the way evolution progressed, by only adding new systems onto existing ones and deactivating older unneeded ones while leaving the mechanisms in place. It's why the brain is built in layers like an onion, around a core called the lizard brain surrounded by the limbic system or mammal brain with all the warm fuzzy emotions and altruism, followed finally by the neocortex or human brain, seat of abstract thinking and more advanced consciousness. Evolution can't remove old unneeded systems, it can only build on top of them and switch the genes for the old systems off when they're no longer needed. Sort of the way you see modern cities built over old ruins of stone buildings.

Yes - you could see it like this - but in the case of "the reptile brain" or "basic mammal brain" - it's not so, that these are the shabby old stuff.
They work beautifully well - and we wouldn't get overly far without them, too.
No fear, aggression, sexual desires - no love and compassion-base - not even Spok would get anywhere!

Originally Posted by Darkmatters

The main difference I can see between your description of what evolution is and Xei's is that I can understand his! So, alleles is just another word for genes? Sheesh! If they mean genes, why don't they just SAY genes?! Scientists - making their ideas incomprehensible to the rest of the world for hundreds of years…

Pööh! biggrin.gif

Well I found my little picture on 'descent with modification' also nice - only with rabbits and carrots, and without explaining why the light grey ones are better carrot munchers - but anyway!

And this is what I wrote on 'allelic frequency':

"If we map the different forms of genes (alleles) of a population and after a few generations, the frequency changes - evolution has occurred." There is a slight semantic difference - none our business here, though.

But you are right of course - hence my platonic sighing at maestro Xei.
This can't even hope to beat werewolves feeling nice in the next ice age and singing mice! I stand humbled!

Originally Posted by Darkmatters

Xei ... - And I have heard about people growing tumors or lumps filled with teeth and hair etc… nasty stuff! In fact I went up and had lunch right after reading this and almost gagged a couple of times, so thanks for that! :hurl: But it's all in the name of science, so I can deal.

Aand - another pöööh! That was "my tumour" which made you gag!! biggrin.gif

Originally Posted by Darkmatters

So yeah, obviously then if an old recessive gene or trait or whatever becomes activated, it takes effect immediately and completely in the offspring. Wicked! I assume that's contingent on the trait being compatible - I mean, something far removed in evolutionary timescale like scales or fins wouldn't be able to develop on a human, right? Or would it? Maybe some kind of "mermaid mutation"? I've laughed myself hoarse a few times over commercials for that mermaid show that purports to show real evidence and footage of living mermaids, but maybe there actually could be some form of human with scales or fins (though highly doubtful it would incorporate a human torso and head with a fish tail… )

Hey, I Just realized - there are people with webbed fingers and toes - not exactly fins, but close! So maybe an Oswald Cobblepot (the Penguin from Batman Returns) could be a possibility, or something similar, after all. (LOL ok, never mind - he was a freakin' PENGUIN - not a fish!! Not one of our ancestors.. )

It is probably not so, that all and everything, which is in the human genome, can come to expression suddenly just like that. But remember the gills - you and me, we had them expressed already. What about more freaky stuff showing up in the final phenotype (the shape of an organism)?
As you found yourself - webbing is easy.
But once you have something rather extreme, you are quite likely going to end up as a tiny little blob of "blood" in sanitary trash after a very early spontaneous abort - completely unnoticed by the world. Gagging already? biggrin.gif

Another thing - we have a lot of so called "junk-DNA" - non-coding bits, which seem to be good for nothing. They could well come in for evolutionary purposes. When I studied, junk-DNA was just a riddle - but I believe nowadays we understand more about it..?

Originally Posted by Box77

1. The apparently fact that it's possible to erase memories and restore them by using pulses of light. How scientists used a virus to deliver a gene to some neurons in order to produce a series of light-responsive proteins, etc.

It is meanwhile possible to erase traumatic memories with drugs given at crucial points in time. But I guess, what you are getting at is completely different. I do not know, what you could mean and agree with Darkmatters - a link would be fine!

Edit: I saw your two links just now - thank you - will get back to you at a later point!

Originally Posted by Box77

2. The apparently fact that it was found vitamin B3 in a group of eight ancient, carbon-rich meteorites, and the possibility that it was generated out of earth, etc.

I was studying something about proteins, enzymes, vitamins, etc. And it called my attention the structure of all these sort of molecules, including ADN, which I cannot find random at all. And I wondered, under a scientific field, if life could have been originated out of earth, or at least its basic components more than just the chemical elements but the complex molecules.

Yeah - but what does this tell you? I know, we found an organic* macromolecule somewhere.
Thing is - bigger organic molecules would only be the basis for further steps towards life, such as the hypothetical hyper-cycles I mentioned.
It is easier to propose, that such molecules could have come into being a myriad times all over the cosmos, than actual life.
So it might mean, that where that came from is life - or it means there are just carbon based molecules.
And even if there was life which "made" this vitamin B - it would still not follow, that we share a common ancestry.

One also has to take into account, that any life will probably be carbon-based - simply because of carbon's traits as an atom.
Silicate could also work - but not much else. And silicate is less likely for reasons, I can't pull out of my nose right now.
If there is oxygen and hydrogen, including in the form of liquid water, carbon, nitrogen, some sulphur and phosphate - and some extra energy from volcanism, or impacts, or cosmic radiation, or something - these molecules can form.
What would actually be suspicious on account of common ancestry, would be finding actual DNA or RNA identical to ours or very similar in life from outer space. But it's all science fiction up to now, idle speculation.

Of course these molecules are not random - atoms follow their structure and chemical attributes concerning with what they go into binding. Certain molecules are bound to happen, just simply because of how chemistry works.
I'm not saying, we would know all and everything about how organic* macromolecules form spontaneously, though.

Could you explain to me, what you mean with "ADN" please?

* "Organic" only denominates the structure of these molecules - namely (often complex) hydro-carbons.
It does not mean, that such a molecule was necessarily once "made" by an organism.

But they are out there! I want to and do quite firmly believe!!

Originally Posted by StephL

Could you explain to me, what you mean with "ADN" please?

DNA!!!!! Sorry, once again my language neural connections are playing those tricks on me... (Already fixed it, thanks!)

Edit: More than an answer, some questions

Finally I reviewed the whole thread and some intrigues came up to my mind along the way:

Am I wrong or during the gene transmission from one generation to another, it is the male progenitor who has the major chances to 'inject' new memory-based information into his DNA sequence because of its always producing new gametes rather than the females who have all of her gametes somehow already there? Perhaps that would be the reason why female gametes would get kind of age-worn?

Some time ago I was fascinated with the phenomena that occurred with the Brine Flies (Short video here: Alien Empire III - Brine flies. - YouTube) and I thought it was evolution taking place already. Although after some discussion it was told that what is happening there is just the adaptation of a species into an environmental change. I got confused by the concepts, but isn't it that adaptation is the first step towards the evolution of a species? I would like to hear a more detailed explanation about what is exactly happening there. I think there could be very useful information about insect evolution here.

I don't think that the origin of life is completely outside of its progression because of the first generations after its start, wouldn't it be somehow the first steps of its evolution?

Another thank you to Darkmatters for this thread - I had such an itch in my fingers to finally get somewhere in the creationist debate next door.
And it simply does not seem to happen!
But this here is much better in terms of entertainment and educationary experiences anyway!!

Originally Posted by Box77

Am I wrong or during the gene transmission from one generation to another, it is the male progenitor who has the major chances to 'inject' new memory-based information into his DNA sequence because of its always producing new gametes rather than the females who have all of her gametes somehow already there? Perhaps that would be the reason why female gametes would get kind of age-worn?

Just on this shortly:
First of all - their findings are not about classic genetics but something unusual.
They talk about free olfactory receptors in the bloodstream of other species, and note that there are olfactory receptors to be found in sperm as well. As far as I know, sperm use such receptors to find out where to swim to.
Sperm with receptors playing a role in our specific case here is a mere speculation, though - but if it were so - it would be a quite special and unusual case, I believe. It could well be, and is probably more likely, that "classical epigenetic happenings" are the mechanism here.

And I believe, it is rather the other way round with men and women adding something new!
But maybe not so, if you only look at epigenetics - you might have a point here - does somebody have an idea on that?

Otherwise and repeating myself - mutations bring in "diversity" and eggs and their DNA lie about for a long time, which means, that mutations are more likely to occur in eggs than sperm. An example for what causes mutations would be exposition to radiation but also mere chance.
Most mutations are "bad" for the organism in question - but not all of them - otherwise no evolution.

Originally Posted by StephL

Yes - you could see it like this - but in the case of "the reptile brain" or "basic mammal brain" - it's not so, that these are the shabby old stuff.
They work beautifully well - and we wouldn't get overly far without them, too.
No fear, aggression, sexual desires - no love and compassion-base - not even Spok would get anywhere!

Of course, you're right! I wasn't trying to say that the older parts of the brain are unnecessary, or that they've been deactivated, my point with the brain stuff was simply that evolution can only work by building onto already existing systems, and can't remove them. I think I tried to get across all that stuff I learned from Uncle Carl too briefly, just wanted to spit it out quickly and not take up too much space with it, so I reduced it too much and left my meaning a bit ambiguous. I sometimes do that, thanks for straightening it out Officer Spock!

Originally Posted by StephL

Pööh! biggrin.gif

Well I found my little picture on 'descent with modification' also nice - only with rabbits and carrots, and without explaining why the light grey ones are better carrot munchers - but anyway!

Yes, I said all of it was valuable, which includes that part! So touchy today! Sheesh!

Originally Posted by StephL

Aand - another pöööh! That was "my tumour" which made you gag!! biggrin.gif

Sorry, I didn't mean to attribute your tumor to Xei! I just got lazy and was writing the Xei paragraph when I brought that up - I know I mixed up my references. Ok, if it makes you feel better, it was YOU who made me gag, more than Xei! Better now?

Originally Posted by StephL

It is probably not so, that all and everything, which is in the human genome, can come to expression suddenly just like that. But remember the gills - you and me, we had them expressed already. What about more freaky stuff showing up in the final phenotype (the shape of an organism)?
As you found yourself - webbing is easy.
But once you have something rather extreme, you are quite likely going to end up as a tiny little blob of "blood" in sanitary trash after a very early spontaneous abort - completely unnoticed by the world. Gagging already? biggrin.gif

Haha… well, I'm not eating right now, and hopefully I won't think of that when I am..

Originally Posted by StephL

Another thing - we have a lot of so called "junk-DNA" - non-coding bits, which seem to be good for nothing. They could well come in for evolutionary purposes. When I studied, junk-DNA was just a riddle - but I believe nowadays we understand more about it..?

Exploring the vast junkyard that is DNA (< mutant smilie)

Originally Posted by StephL

It is meanwhile possible to erase traumatic memories with drugs given at crucial points in time. But I guess, what you are getting at is completely different. I do not know, what you could mean and agree with Darkmatters - a link would be fine!

I learned some time ago that apparently every time you recall a memory you're actually changing it, recalling is an active process that slightly 're-writes' the memory. Just on a related note, I haven't read the article yet.