Explaining Macroevolution to a creationist

[he_who_is_nobody]

Or , I'd prefer , how a group of single cell organisms became a truly multicellular reproductive animal.

Back on page 4, I wrote:

Wikipedia: Multicellular organism: Origin hypotheses

Stop pretending that this was not already addressed.

 

[We are Borg]

As I just told you, there was never any point in evolutionary history where one kind of animal changed into a fundamentally different kind of animal.

If this was the case would it disprove evolution?

 

[Dragan Glas]

Greetings,

Back on page 4, I wrote:

Stop pretending that this was not already addressed.

Sorry HWIN, I didn't mean to miss out your own contribution - I forgot about it when I was typing my post.

Kindest regards,

James

 

[Sparhafoc]

If this was the case would it disprove evolution?

If we're talking about animals, then it would require an entirely new understanding of Biology, Chemistry, and Physics. Not only would evolution be false, but so would most other things we know - it would for all intents and purposes be magic.

Allakhazam.... *wiggles nose*... now you have 6 legs!

Or Pokemon.

The Theory of Pokemon Evolution is usually how poorly informed Creationists imagine scientists conceive of the evolution of species - special individuals, with special traits, that jump from one binary snapshot to the next binary snapshot - black to white - not a gradient in sight!

 

[We are Borg]

What i find interesting with evolution is that there is no exception to the rule. Normally you say its x except when y, but evolution does not have an exception.

 

[JohnHeintz]

Back on page 4, I wrote:

Stop pretending that this was not already addressed.

That's an article. Not a discussion. Also, it says hypothesis right in the title.

 

[JohnHeintz]

Back on page 4, I wrote:

Stop pretending that this was not already addressed.

That's an article. Not a discussion. Also, it says hypothesis right in the title.

Greetings,


The reason as to why you're not communicating very well is because, as Aron notes, you keep dodging his questions.

If you know how to tell they're related, say so, and explain it. If not, acknowledge that you don't, and let him explain it to you.

And I provided a link to an article and paper on how single-celled organisms became multicellular organisms in the presence of a predatory micro-organism.

Either you didn't read it, didn't understand it or dismissed it.

Perhaps you should answer Aron's question - and read the article to which I linked - before Aron posts his next reply.

Kindest regards,

James

Two things.
One. I did answer. I asked him to explain how genetics shows relationship.
Two. Your article shows algae forming a biofilm. This is not uncommon in algae. I'm asking about how the single cell organisms became something like a worm, trilobite or fish

 

[Sparhafoc]

Also, it says hypothesis right in the title.

And...?

 

[Sparhafoc]

I'm asking about how the single cell organisms became something like a worm, trilobite or fish

When they collect enough XP, they level up and evolve new appendages.

C'mon.... it's the Creationist Theory of Evolution by Pokemon - you should know that!

 

[Sparhafoc]

One. I did answer. I asked him to explain how genetics shows relationship.

Just to note - a question and an answer are not the same things.

 

[Deleted member 619]

What i find interesting with evolution is that there is no exception to the rule. Normally you say its x except when y, but evolution does not have an exception.

What's funniest about this is that, if there's an exception, it wasn't a rule. It might have approximated one, in the same way that Newton's rule - universal gravitation - approximated gravity, but there was an exception that proved it wrong in the form of the precession rate of Mercury's perihelion.

The origin of this little nugget of wisdom is purely linguistic, and stems from the fact that words don't have inherent meaning.

A proof, in formal logic, is a test. It's a study of the logical structure of an argument. In other words, the original phrase 'the exception proves the rule' mean that it presents a test for the rule, with the implicit conclusion that it failed the test. Unfortunately, because the word 'prove' now means to show something to be true - only one possible outcome of a proof - the truism 'the exception proves the rule' is no longer true in the vernacular, and it fact it means almost exactly the opposite of when it was actually true.

If there's an exception, there was something not correct or accurate about the rule.

 

[Dragan Glas]

Greetings,,

Two things.
One. I did answer. I asked him to explain how genetics shows relationship.

Aron first asked his question of you on page 3:

It's a funny thing about believers vs non-believers. If you ask me a question, I will answer it as best I can. I will never ever try to duck or dodge or ignore it, like believers always do. When I ask a question, it is because I am either trying to understand your position or reason you out of it. But believers always ALWAYS duck and dodge or ignore my questions, which is why I have to repeat them over and over again. The only questions believers ever ask are things they don't want the answers to. When they hear that I have the answer, they don't care. They were hoping I couldn't answer, and they're going to ignore whatever answer I give. Because they don't want to understand the reality. They just want to make-believe in their fantasy.

If they are related, there is a way to tell. Do you know how we could do that?

On page 4, you replied:

We have evidence NOW. Back then , if a remote control car could be demonstrated, it would have been considered magic or sorcery

... to which Aron replied:

Since you STILL didn't answer ANY of my questions, I'll have to repeat them all AGAIN.

JohnHeintz said:
Anyway. Let's answer your questions about dogs , cats and the deer.
Of course I believe that dog breeds are related to each other and wolves. They probably are related to coyotes and wild dogs and dingoes.

If they are related, there is a way to tell. Do you know how we could do that?

... to which you replied:

The African wild dog probably is related.
We know the wolf and dog are. Seriously, with the dog and wolf it's really just wild vs domestic.
I hope this answers your question

On page 7, Aron replied :

"Probably"? No, that doesn't answer my question. Repeating another question I already asked you: If they are related, there is a way to tell. Do you know how we could do that?

... which resulted in you opining that you "don't seem to be communicating very effectively on this "are they related" topic."

The reason is simple:

You never answered his question.

Aron has continued to ask you "how to tell if they are related".

Your eventual answer - after multiple attempts by Aron to get any sort of answer from you - was, "they're probably related".

How does that answer Aron's question.

Why don't you do as I suggested in my previous post:
1) If you know how to tell, say so, and explain it;
2) If not, ask, and we're all certain that Aron will be only too happy to explain it to you (and anyone else who doesn't know).

Two. Your article shows algae forming a biofilm. This is not uncommon in algae.

In saying this, you ignore what the paper actually says:

Nearly all macroscopic life is multicellular. As Leo Buss emphasized in The Evolution of Individuality, the very existence of integrated multicellular organisms is an outcome of evolutionary processes, not a starting condition1. It seems, in fact, to be a common outcome: multicellular organisms have evolved from unicellular ancestors dozens of times2,3,4. Animals, land plants, fungi, red algae, brown algae, several groups of green algae, cellular and acrasid slime molds, and colonial ciliates, among others, each descend from a different unicellular ancestor4,5.

Having noted that multicellularity has evolved many times, it then goes onto give examples of such under laboratory conditions:

The experimental evolution of multicellularity in otherwise unicellular microbes enables real-time observations of morphological, developmental, and genetic changes that attend the transition to multicellular life. Boraas and colleagues exposed cultures of the green alga Chlorella vulgaris to predation by the flagellate Ochromonas vallescia, resulting in the evolution of small, heritably stable algal colonies6. Becks and colleagues showed that exposure to the predatory rotifer Brachionus calyciflorus selected for heritable changes in the rate of formation of multicellular palmelloids in the green alga Chlamydomonas reinhardtii7. Ratcliff and colleagues have shown that selection for an increased rate of settling out of liquid suspension consistently results in the evolution of multicellular ‘snowflake’ colonies in the yeast Saccharomyces cerevisiae8 and also results in the evolution of simple multicellular structures in C. reinhardtii9.

The paper hypothesises that predation was a possible driver towards multicellularity, before giving a quick overview of their research:

In this study, we present experiments in which we used the ciliate predator Paramecium tetraurelia to select for the de novo evolution of multicellularity in outcrossed populations of C. reinhardtii. We describe the heritable multicellular life cycles that evolved and compare them to the ancestral, unicellular life cycle. In addition, we show that the evolved multicellular life cycles are stable over thousands of asexual generations in the absence of predators. Comparative assays show that the evolved multicellular phenotypes provide a fitness advantage over unicellular algae in the presence of predators. Because C. reinhardtii has no multicellular ancestors, these experiments represent a completely novel origin of obligate multicellularity14,15.

In other words, multicellular organisms evolved, and passed on their multicellular trait to their offspring - despite there being no predatory driver present. As the authors note:

The strains have maintained their evolved characteristics of simple multicellularity in the absence of predators for four years as unfrozen, in-use laboratory strains. Therefore, we are confident that the phenotypic traits that we report below are stably heritable.

This means that multicellularity evolved from unicellular organisms due to predation.

You may ask, "Why didn't the single-celled organisms just give rise to bigger versions of themselves - to be "too big" for the predator's "mouth"?"

As the authors explain:

Under selection for increased size, formation of multicellular structures may be an easier route than increasing cell size because of trade-offs imposed by scaling relationships (chiefly the reduction in surface-area-to-volume ratio)18, because more mutational paths are available, and/or because available mutations have fewer or less severe pleiotropic effects.

But there's more: the authors also note that:

Observations in other species suggest that the relative ease of transitioning from a unicellular to a multicellular life cycle is at least somewhat general. Similar transitions reportedly occurred within 100 generations in the green alga Chlorella vulgaris6 and within 300 generations in the yeast Saccharomyces cerevisiae8. Although there have surely been many microbial evolution experiments in which multicellularity did not evolve, we can at least be confident that this phenomenon is not unique to Chlamydomonas. Grosberg and Strathmann4 may have been right to call the evolution of multicellularity a “minor major transition”.

However, the available evidence also suggests a substantial stochastic component to the evolution of multicellularity. In previous experiments using settling selection as opposed to predation selection, multicellular structures evolved in one of ten selected populations in C. reinhardtii9 and in “about 70%” of “many” selected populations in C. vulgaris6. In the experiment reported here, a variety of multicellular forms evolved in two of five selected populations. Only in S. cerevisiae has the evolution of such forms proven consistent across replicate populations8.

So, it appears that predation isn't the only - or simplest - way for multicellularity to evolve.

Now, in particular reference to your "biofilm" comment, the paper states this':

Other phenotypic differences could be easily discerned by light microscopy. For example, in Fig. 1, an external membrane is visible around both evolved multicellular colonies, indicating that they formed clonally via repeated cell division within the cluster, rather than via aggregation.

Got that?

We have "an external membrane" around our multicellular bodies.

It's called "skin".

I'm asking about how the single cell oorganisms became something like a worm, trilobite or fish

Evolution - multicellular microorganisms having evolved, through incremental changes, ever more multicellular organism came into being that were best suited for their environments.

Kindest regards,

James

 

[We are Borg]

@Dragan Glas when using page numbers like you do people can get confused because you can alter how many posts on one page. In the header of the post you see #number you can copy that link and use it in posts it takes you straight to that post and isolate it like so https://leagueofreason.org.uk/index...oevolution-to-a-creationist.16705/post-194019

 

[Dragan Glas]

Greetings,

@Dragan Glas when using page numbers like you do people can get confused because you can alter how many posts on one page. In the header of the post you see #number you can copy that link and use it in posts it takes you straight to that post and isolate it like so https://leagueofreason.org.uk/index...oevolution-to-a-creationist.16705/post-194019

Understood, WAB, I still tend to use page numbers for multiple posts on the same page.

Kindest regards,

James

 

[We are Borg]

Greetings,


Understood, WAB, I still tend to use page numbers for multiple posts on the same page.

Kindest regards,

James

I’m just like you use page numbers but if some one alter the default setting then it no longer works for that person.

 

[Dragan Glas]

Greetings,

I’m just like you use page numbers but if some one alter the default setting then it no longer works for that person.

I'll bear that in mind the next time I trawl through a thread to pick out posters' replies,

Thanks.

Kindest regards,

James

 

[he_who_is_nobody]

That's an article. Not a discussion. Also, it says hypothesis right in the title.

You said you just wanted an explanation. So what is the problem if some of them say hypothesis? Beyond that, you do realize how Wikipedia works. There are citations for all the sections. Thus, you can click through and find the actual scientific studies for each of those.

Two. Your article shows algae forming a biofilm. This is not uncommon in algae. I'm asking about how the single cell organisms became something like a worm, trilobite or fish

Beyond what Dragan Glas has already posted, it appears you are not asking the correct question. You said you want to see single cellular life becoming multicellular. Both Dragan Glas and I have already provided that for you. Now, it appears, you are actually asking for single cellular life to give rise to worms, trilobites, and fishes. This is not what evolutionary theory teaches and more akin to Pokemon evolution.

 

[Sparhafoc]

And that's.... just a theory!


/canned laughter

 

[Deleted member 619]

I have a really vague memory of colonies of single-celled organisms that agglomerate and become functionally a single organism with distributed metabolism. It's a passing memory, might have been in one of Dicks books. Ring any bells?

That would seem to fit the bill for a real-world example of how multicellularity can evolve, which is the real stumbling block here, whether our interlocutor would admit it or not.

In any the glib-seeming 'you did it yourself in nine months' is a lot more profound than it seems once you factor in a single process at the heart of complex evolution: embryology. We don't have to get from a single cell to a complex organism in evolutionary terms, because evolution isn't the process that gets us from cell to complex organism. Biodiversity is really a story of differing embryology driven by tiny chemical changes in the make-up of the first cell and the ribonucleic acid that underpins it. Evolution takes us from single cell to single cell, and embryology does the rest, with the environment acting as a filter.

 

[Deleted member 619]

And that's.... just a theory!


/canned laughter

And that's the best bit. It doesn't matter that it's only an hypothesis - nor even that it isn't the only hypothesis on the table - it's that, even for the questions we don't have answers to - which of necessity is going to include the exact mechanisms by which all of these processes did occur - we have plausible hypotheses consistent with the data and a some consequences hy which we might, with future observations, whittle the field down until we're left with only one best contender and get on with trying to falsify it.

Part of the problem we face, as sci-commers or even just as people who talk about this shit on the interwebz, is the tendency to treat it all piecemeal, always responding to some version of the elbow joint of the lesser spotted weasel frog. Playing whack-a-mole with individual claims rather than getting ahead of it.

And this is true of almost all things now. You almost can't express an opinion on whether scissors or toenail clippers are best for clipping your toenails without being immediately consigned to some box, complete with assumed worldview.

ETA: I shuld add, that's why I maintain a blog. It means I can treat a topic completely in one pass without interruption, derail or shoutdown. It's very liberating, but it's also no substitute for solid discourse on weighty stuff.