Is the evolution of plants as we know them today, even possible?
Debate Rounds (4)
round 1 will be acceptance, outline your reasoning.
rounds 2-4 anything goes. Feel free to defend and attack, defend or just attack, cross examine ect.
Allow me to define plant. I think this is a fair definition:
"Plants, also called green plants, are multicellular eukaryotes of the kingdom Plantae. They form an unranked clade Viridiplantae (Latin for green plants) that includes the flowering plants, conifers and other gymnosperms, ferns, clubmosses, hornworts, liverworts, mosses and the green algae. Green plants exclude the red and brown algae, the fungi, archaea, bacteria and animals."
Is the evolution of plants as we know them today, even possible? I would affirm that it is not. It is a terrible explanation for the diversity and mere existence of plant life we see all over the world and virtually impossible through gradual means to get any meaningful plant life as we know it.
An evolutionary model would require an answer to what came first, the plant or the seed?
An evolutionary model will have to show that cellular organisms can transform into plants and organize themselves in such a way that they form a meaningful plant.
A very basic overview of plant requirements.
All plants require light, carbon dioxide, water, nitrogen, phosphorus, potassium. A lot of the success of plants is being found to be correlated with micro nutrients as well. These include calcium, zinc, magnesium, manganese, sulfates, boron, silicon.
There is a problem in explaining the root system. Roots can easily be drowned but always need moisture to thrive. They also require certain bacterium's and fungi to help in transporting nutrients for uptake.
There is a problem in explaining seed development. in order for a plant to reproduce it is going to require pollen or a scenario where it can clone itself. Bees for example are a huge aid in pollination. If plants existed prior to bees, maybe they were all hermaphrodites that self pollinated. But why would a plant develop or know that it needed to develop pollen in the first place?
In the environment for the first plant, how long did it live? Was there sufficient C02 availability for it to spring forth? Did it develop without roots? When did roots come into play? how did it reproduce?
These unanswerable questions among many more will show its an impossible feat. Thank you.
If pro would like to explain for example how the first root system came about and from what it came from
Where pollen and seeds developed from
How long ago the first plant or plants showed up
How photosynthesis began
Provide any examples of any genus of plants making a transition from say tomatoes to potatoes.
As I have said before, its not possible for any plant to just occur out of nowhere even through gradual means. There isn't a transition possible of non vascular to vascular plants and its never been shown to happen in a laboratory.
Plants are very adaptable. But what they don't do is up and decide to one day pop roots out as the first vascular plant would have to do. I would be interested in how pro thinks the diversity of fruits would be possible to occur with evolution. In other words why would a tomato plant ever start to produce potatoes or cucumbers or pumpkins.
"The total number of plant species in the world is estimated at 270,000. Approximately 1,000 to 2,000 species of plants are edible by humans. About 100 to 200 species of plants play an important role in world commerce, and about 15 species provide the majority of food crops. These include soybeans, peanuts, rice, wheat and bananas."
Now I'm not aware of any model or evidence even through multiple discussions on this very form addressing some of the problems facing an evolution of plants. There will need to be adequate C02, enough nutrients and nutrient availability, enough but not too much sunlight, enough access to water depending on which plant we are talking about.
Anyone interested in plant basics is free to view them here.
Thanks Con for the debate.
Con has made some wild assertions, so I will address them in my case.
Con defined plant, but didn't define evolution or possible.
Instead, I will attempt to clarify what this resolution is about.
evolution - the process by which different kinds of living organisms have developed and diversified from earlier forms during the history of the earth.
possible - able to happen.
The resolution asks if the development and diversification, during the history of the earth, of multi-cellular eukaryotes of the kingdom Plantae, in their current from, is able to have happened.
Well, I'm here to affirm that.
While Pro thinks that "an evolutionary model will have to show that cellular organisms can transform into plants and organize themselves in such a way that they form a meaningful plant," this is simply not true.
Evolution is merely the diversification of organisms, not the origins of the first organism.
But, I'm a science guy, so I will affirm, not only the evolution of plants, but that the origin of these eukaryotes was not only possible, but is well understood.
*The Origin of Life On Earth - Abiogenesis*
1. With an atmosphere, water salinity, inorganic compounds, electricity, and UV rays likely of a prebiotic earth, inorganic compounds can naturally become organic compounds in the form of amino acids.
2. Amino acids make up proteins, in chains called polypeptides, and the sequence of the amino acid chain causes the polypeptide to fold into a shape that is biologically active.
3. Biologically active amino acid sequences can in fact metabolize compounds.
4. Amino acids are catalysts, because they tend to increase the rate of chemical reactions, and in a prebotic network full of amino acids, RNA can emerge due to its auto-catalytic property.
5. RNA is also self-replicating, and because of this, was able to thrive in a prebiotic amino acid network.
6. With biologically active amino acid chains and self-replicating RNA, membranes can form, which all combined forms a protocell.
7. Protocells can metabolize with amino acids and replicate with RNA, and this is the origin of genetic polymers.
8. A protocell with a membrane/barrier and genetic polymers that can metabolize and self replicate is a full blown living cell, and these single cells are life; they're simple life, but they're life.
9. These simple life forms would need to eventually consume more, and the network of amino acids and other compounds in the region were in fact edible.
10. Inorganic compounds of a prebiotic earth can be come organic amino acid compounds, which themselves can become biologically active and can catalyze reactions that favor an emergence of auto-catalytic RNA, which can self-replicate and thus allow for a cell with a membrane and genetic polymers that replicates and metabolizes available compounds in the prebiotic network.
So, we have the first living cell from abiogenesis, metabolizing with amino acids and replicating with RNA.
Algal mats are filled with cyan colored bacteria, sometimes called blue-green algae or Cyanobacteria, and these mats form on the surface of the water and are the precursor to plants.
This algae evolved "from a single-celled, scaly, biflagellate ancestor that gave rise on the one side to the green algae of the Chlorophyta and on the other side to the Streptophyta"
Given that there is a ton of Cyanobacteria, which are photosynthetic and reproductive, in an algal mat, it makes sense that other photosynthetic and reproductive organisms could thrive in a similar network.
The first plants then, evolved on the surface of these algal mats, and were not seed reproductive, rather they used spores like their non-plant ancestors.
All current evidence indicates that "the monophyletic origin of embryophytes, and that Charophyceae (Charophyta), especially Coleochaetales and/or Charales, are the closest living algal relatives of land plants."
Here's how the origin of plants went down:
Inorganic compounds-->organic amino acid compounds-->biologically active catalytic network-->emergence of auto-catalytic and self-replicating RNA-->primitive encapsulation of amino acids and RNA (single cell)-->bacteria-->cyanobacteria-->algal mats-->photosynthetic, spore bearing plants.
So, not only is plant evolution/origin possible, it's well understood and indicates that algae is responsible for the first plants.
Now pro has shown nothing in the way in which the structures found on modern plants could have evolved into what we have today in the forms of roots, stems, leaves or really any process that vascular plants utilize as being evolvable.
Pro has merely taken the route of assuming well, inorganic compounds can become organic compounds and since these compounds can be assumed for some reason to form meaningful organic organisms we can just assume and take his word for it that somehow, someway plants will just form, because hey, that's the way it has to go.
I find it interesting that pro even stated the following about amino acids:
"2. Amino acids make up proteins, in chains called polypeptides, and the sequence of the amino acid chain causes the polypeptide to fold into a shape that is biologically active."
and yet by this very same source they explain the following:
"The synthesis of a polypeptide, however, is not equivalent to the production of a functional protein. To be useful, polypeptides must fold into distinct three-dimensional conformations, and in many cases multiple polypeptide chains must assemble into a functional complex. In addition, many proteins undergo further modifications, including cleavage and the covalent attachment of carbohydrates and lipids, that are critical for the function and correct localization of proteins within the cell."
I'm curious what Pro is basing the assumption that amino acids which make polypeptides will make meaningful ones without a code written in them to do so?
Yet again Pro proposes a very misleading dialogue by assuming abiogenesis by saying this:
"Biologically active amino acid sequences can in fact metabolize compounds."
Now I don't know if Pro simply didn't read his own sources that explain the details behind how these things happen. I guess if I wanted people to believe these things happen on their own and theres no requirements I would do the same. His statement is nullified with this:
"Conversion of glucose to pyruvate via reactions homologous to the non-phosphorylated Entner-Doudoroff (non-P ED) pathway could be achieved in the presence of two amino acid catalysts, cysteine and histidine"
Now this debate is not on abiogenesis. Its fine if Pro wants to assume that's the pathway and wishes to demonstrate that as he does later down the line that algae mats went on to form all plants, vascular and non vascular alike, ok fine. But to begin to outline that because abiogenesis is possible; Note: POSSIBLE, you know if you have the right circumstances and things like that and polypeptides know how to fold into 3 dimensional conformations ect ect. Doesn't provide ANY information in the way of describing the process and routes taken to form structures on vascular plants, or non vascular plants alike
Pro cited a Journal to provide a way for plants to evolve, lets examine that journal.
"Actin generally occurs in complex families in multicellular organisms (e.g., animals, land plants) and as single copies in many protists (e.g., ciliates, fungi, red algae, most green algae, diplomonads [Bhattacharya and Ehlting 1995; Drouin, Moniz de Sa", and Zuker 1995]). The role of actin in muscle contraction and its importance as a major component of the cytoskeleton has led to the detailed characterization of actin gene families in animals. Such data show tissue speci@257;c expression of actins, supporting the hypothesis that the multiple actin genes encode proteins with speci@257;c and different cellular functions (see Herman 1993; Sheterline, Clayton, and Sparrow 1995)."
Now the conclusion is that actin occurring pretty much across the board in multicellular organisms will encode proteins with specific and different cellular functions. When it comes to plants:
"The angiosperms also contain complex and relatively highly divergent actin gene families (Hightower and Meagher 1986; Baird and Meagher 1987; McLean et al. 1990; Moniz de Sa" and Drouin 1996). The relationship between the large number and subclasses of angiosperm actins and their function(s) is, however, unclear."
Is pro prepared to explain their functions? Can pro show us that actins can change to code from one plant to the next? Why would a thriving plant do that?
The author continues to write:
"The origin and phylogeny of actin genes and their role in the evolution of the angiosperms are therefore largely unresolved. In addition, virtually all existing studies on land plant actin gene origin and evolution (e.g., Hightower and Meagher 1986; McDowell et al. 1996; Moniz de Sa" and Drouin 1996) have focused on analyses of angiosperms and have not included enough members of earlier-diverging lineages within the Streptophyta (sensu Bremer 1985)."
I think its great that Pro jumped to the conclusion that "not only is plant evolution/origin possible, it's well understood and indicates that algae is responsible for the first plants".
Yet the origin of actin genes and their role in the evolution of angiosperms are largely unresolved and apparently ignoring a large group of existing Streptophya...
Beating all the odds though Pro assumes something he should not because as the author points out:
The Streptophyta are the sister group to the Chlorophyta (sensu Sluiman 1985), and together they form the Viridiplantae (Cavalier-Smith 1981)"
"Molecular phylogenetic studies show that the origin of the Viridiplantae can be interpreted as a set of evolutionary ""steps"" from a single-celled, scaly, bi@258;agellate ancestor that gave rise on the one side to the green algae of the Chlorophyta and on the other side to the Streptophyta"
So on the basis of a group of Streptophya which have a large difference in actin that encode specific genes, which we don't understand how it happened, what the origins were or why they should have evolved at all, where not enough conclusive studies have been made on the divergence of Streptophyta from Chlorophyta; We are to just up and assume these two things must have evolved from a single celled, scaly, biflagellate ancestor? Can pro explain why two Virdiplantae forefathers emerged instead of just one? Or that just because they are similar they must have evolved? These are not reasons, these are just speculations. Its no different than the watchmaker argument in which well here is a watch, so there must be a watchmaker. Where is the explanation of HOW that watch was made?
Did Pro give us an example from the laboratory showing plant evolution?
Did Pro cite a conclusive study showing how to go from Streptophyta to angiosperms?
"Given that there is a ton of Cyanobacteria, which are photosynthetic and reproductive, in an algal mat, it makes sense that other photosynthetic and reproductive organisms could thrive in a similar network"
Well that's nice. why does it make sense? Something more than an assertion would be nice.
Pro then said:
"The first plants then, evolved on the surface of these algal mats, and were not seed reproductive, rather they used spores like their non-plant ancestors."
Now I have looked everywhere to find plants that grow on top of algal mats. I could find nothing. Does pro have an example of something from the plant kingdom that finds its home on the top of an agal mat? How or why it made its way to land when it was doing just fine in the water?
Here is a basic article on how these actually function
I find it interesting that Cyanobacteria aka toxic algae is supposed to be the forfather of all plants. I'm shedding their ability to capture nitrogen from the air for future plants was a useful thing to do as well.
Thanks Con for your response.
Con's agreed to my definitions for the terms of the resolution, so that's good, right?
Therefore, the resolution is about plants diversifying over time and if *this* could have happened.
I'll respond to Con and add a little more to my case.
I would like to reiterate that plants originated from photosynthetic cyanobacteria which were descendants of early bacteria, which were descendants of the earliest living cells, as outlined in my abiogenesis explanation, and since the origin of the first plant, plants have evolved to dominate on land and proliferate throughout the world.
"Pro has shown nothing in the way in which the structures found on modern plants could have evolved into what we have today in the forms of roots, stems, leaves or really any process that vascular plants utilize as being evolvable."
Structures found on modern plants?
Con, you stated 1st round that the definition of "plant" included green algae, which have no roots or stems and are not vascular, so why would I have to show such a thing?
If I can show that simple plants evolved, one must affirm.
Check my studies from the 2nd round.
But, here we are:
First, let me explain that PsbO is a protein and a component of the ability to oxidize water using enzymes, which allows organisms to photo-oxidize water while conducting photosynthesis.
Hopefully, most understand that the first step of photosynthesis is to get oxygen from water, so, for photosynthetic organisms, oxidizing water was crucial to survival and reproduction.
So, if we could determine PsbO's origin, then we could find the evolutionary steps to the first photosynthetic plants, the very organisms defined in this here resolution.
From a PNAS published study from the University of British Columbia:
"PsbO did originate from the cyanobacterial ancestor of all plastids..."
Plastids, organelles of plant cells, are the structures that Con should actually be concerned with, as they encompass all of this debate's definition of plants, unlike roots, stems, and vascularity...plastids come from blue-green algae, cyanobacteria.
From the same study:
"the peridinin-containing dinoflagellate branch (H. triquetra) shows conclusively that this type of plastid originated from a red alga by means of a secondary endosymbiosis...this is direct phylogenetic evidence of the red algal origin of the peridinin-type dinoflagellate plastids."
So, there you have it.
All current plants, because they photosynthesize and have plastids, originated from cyanobacteria and red algae confirm this origin...I argue that *these* structures should be what we consider about plant evolution in this debate.
"I'm curious what Pro is basing the assumption that amino acids which make polypeptides will make meaningful ones without a code written in them to do so?"
It's not an assumption, and let me use the quote that Con did, from my source, "polypeptides must fold into distinct three-dimensional conformations, and in many cases multiple polypeptide chains must assemble into a functional complex."
Right, which, because they're amino acids that catalyze reactions, this in fact happens, and if you read the rest of the source, you'll see that "many proteins undergo further modifications, including cleavage and the covalent attachment of carbohydrates and lipids;" this is all well-understood functions of amino acids, in chains called polypeptides.
Also, the term "meaningful" is undefined and meaningless, and catalytic reactions don't necessarily require any code at all.
Polypeptides fold into biologically active structures, 3 dimensional and all, and this all occurs naturally.
"I don't know if Pro simply didn't read his own sources that explain the details behind how these things happen"
So Con quotes my source:
"Conversion of glucose to pyruvate...could be achieved in the presence of two amino acid catalysts, cysteine and histidine"
Yeah, if you had read #4 under my abiogenesis explanation, then you would have seen that the replicated Miller-Urey experiments yielded those two amino acids and tons more.
So, in that pre-biotic catalytic network, metabolism was possible.
Con asks 3 questions about the study mentioning the relationship between the large number and subclasses of angiosperm actins and their functions:
1. "Is pro prepared to explain their functions?
Actins assist in the regulation of gene activity, translocation, architecture of the nucleus, and transcription...pretty crucial things actually.
2. "Can pro show us that actins can change to code from one plant to the next?"
It's called mutation. As the nucleotide sequence changes, via reproduction, mutations occur which result in the change in genetic code, thus actins.
Also, genetic code is added all of the time in a process called polyploidy whereby the offspring have more than 2 gene sets.
3. "Why would a thriving plant do that?"
Why would a thriving plant mutate?
Because as constraints change, so do characteristics that lead an organism to living long enough to reproduce and successfully reproduce.
Even in an ecosystem dominated by thriving plants, constraints still dictate what makes it and what doesn't...constraints.
"Pro jumped to the conclusion that 'not only is plant evolution/origin possible, it's well understood and indicates that algae is responsible for the first plants.' Yet the origin of actin genes and their role in the evolution of angiosperms are largely unresolved."
So, whenever researchers do studies, they have to argue to the public that their study has something called salience.
Salience just means that there is pressing relevance for what it is that you're trying to do a study on, i.e. why should we consider your study relevant?
So, authors typically highlight the lack of information on a particular subject to show why *this* study that they're conducting is salient, or is a pressing scientific necessity to understand.
So, while past studies may have left some of those concepts unclear, *this* study didn't...that's why the authors put that bit in the beginning of the article.
Before 1998, they didn't know what we know now...had you read the rest of the study, you would have seen:
"Many of the evolutionary relationships shown in figure 3 are consistent with accepted ideas of evolution in these groups. The actin genes from the Ulvophyceae and the Chlorophyceae form monophyletic groups, the Prasinophyceae are deeply paraphyletic."
What did figure 3 show?
"The branch shown as a thick line identifies the putative monophyletic origin of the plant REP actin genes."
Con could have just read the study and seen that now we DO understand these relationships, as I have stated.
Instead, Con goes on a rant about how we don't understand something that the study I provided explains...quite clearly actually.
Con asks another question:
"Did Pro cite a conclusive study showing how to go from Streptophyta to angiosperms?"
From the exact same study that Con didn't bother to read in full:
"the Charophyceae are early divergences within the Streptophyta, and the Selaginella, Psilotum, Anemia, and Osmunda actin genes diverge prior to the major radiation of the angiosperms."
Figure 3 showed that, and Con never looked at it...it's a shame really.
I'm out of characters, but if Con doesn't mind, I'll address the last of his arguments next round...Con?
I find it interesting that Pro would cite something along the lines of PsbO as an evidence for the evolution of plants. PsbO (OEE1) is in every single plant because its instrumental to photosynthesis. This is really like saying because all animals have RBC's then they must be related. The study cited is simply a study for identifying and putting together a phylogenetic tree. This was not a lab experiment showing evolution of anything but merely an attempt to find common ancestry between dinoflagellates and photosynthetic organisms that use the same protein (PsbO) as some of the dinoflagellates that also use PsbO. Its quite the obvious statement to say that organisms that all use photosynthesis use the same protein for such a mechanism, why wouldn't they?
Why shouldn't PsbO change?
Plants are hundreds of millions of years old after all and cyanobacteria are 3.5 billion years old.
Its nice to discuss the commonalities but what about all the differences between complex plants and these more simple plant types? None of this goes in the way to give us any explanation as to how we got Tracheobionta or Spermatophyta and this has largely been left untouched the entire debate.
Perhaps at any given time pro will take up the challenge of explaining the evolution behind the major structures we know from vascular plants as roots and stems and leaves. If not that's ok. He is more than able to choose not to.
Pro wants to discuss cell organelles. Sure how about discussing root cells and their organelles?
Its nice to see Pro thinks polypeptides fold themselves. By his own article again:
"Protein folding thus appeared to be a self-assembly process that did not require additional cellular factors. More recent studies, however, have shown that this is not an adequate description of protein folding within the cell. The proper folding of proteins within cells is mediated by the activities of other proteins."
This is the only reason I suggested you simply are not reading your own articles.
Once again Pro made the bold statement of
"Biologically active amino acid sequences can in fact metabolize compounds"
Stood by it despite:
"However, the analytical instrumentation used in this study is up to 10 orders of magnitude more sensitive and can detect a much wider diversity of organic compounds than the techniques available in the 1950s (2, 3). "
"Other efforts have been made to generate organic compounds from simulated early atmospheres containing H2S, most of which were conducted after Miller"s 1958 experiment. A spark discharge was passed through a mixture of CH4, H2O, NH3, and H2S, but no sulfur amino acids were detected (16). A mixture of H2, CH4, NH3, H2O, and H2S was subjected to a spark discharge, and the detection of cysteine, cystine, and possibly methionine was reported (17). "
Pro did not bother to cite a lab specific instance in which actin function was able to change a plant into another plant. Or evolve it if you will.
Pro did not show a change in algae over the hundreds of millions of years we have known it to exist or cyanobacteria for that manner. Its insufficient to say a plant would simply mutate itself so much so that it becomes over time a whole different plant containing roots and leaves and stems. Theres simply no evidence for it or Pro happily would have cited it. If it did make this change we wouldn't have anymore green algae. It certainly would have no resemblance to ancient green algae.
I appreciate these scientists for shedding more light where there needs to be more. However with that said it still stands that the relationship as to how these things actually did any evolving at all is yet to be shown.
The entirety of Pros argument seems to rest upon phylogenetic trees. That's nice. But it still shows nothing in the way of explaining pretty much everything regarding how these changes occurred and if they are a result of evolution or a result of varieties of plants merely always existing as we know them today in the varieties we see them in today.
Another thing to consider is the fossil record. Plants for the most part are still the same as they were millions of years ago.
The 52.2-million-year-old tomatillo was discovered at the fossil-rich Laguna del Hunco, Argentina, where ancient lakebeds interlayer with volcanic ashes, providing paleontologists with precisely dated discoveries
"Scientists sequenced the tomato genome in May 2012. The tomato family molecular clock, based on the genetic data and fossil evidence, suggests the tomato genome expanded abruptly about 60 million years ago. A molecular clock estimates when species diverged in the past."
"Now, thanks to the tomatillo find, the Solanaceae molecular clock is too young, Wilf said. During his talk, he listed 11 fossils from Laguna del Hunco, such as cycads, trees and the tomatillo, that show their molecular clocks are too young."
"Almost all of the molecular ages are younger than the fossils," Wilf said
Same plant, 52 million years later.
"The world's oldest peach fossils have been discovered in southwestern China, according to a new report. At more than 2.5 million years old, the fruits predate the arrival of humans to the region."
"The fruit fossils were found in a rock layer that dates back to the later part of the Pliocene epoch, the geological period that stretches from 5.3 million to 2.6 million years ago. The pits so strongly resembled living peach pits that Su and his colleagues put the fossils through a battery of tests to confirm that they weren't left there by more recent contamination, perhaps from a hungry construction worker, for example."
After 5.3 to 2.6 million years old, the peach pit was so much so the same that they thought it might have been thrown out by a recent construction worker.
Now of course plants being quick to decay and particularly more difficult to fossilize makes it harder to find really old fossils of plants and various fruits. But we do have them. Evergreens were Evergreens. Tomatoes were tomatoes. ect ect. Sure they may have looked a little different. What wouldn't after being around for such a long time? But they all are still in the same classification of their respective groups and nothing more has happened other than different plants adapting to their landscapes. Tomatoes never became potatoes. Nothing ever sprang up from an algae mat.
Its nice to come up with genetic similarities but as the tomatotilla has shown, its prone to error. All it shows are interesting similarities.
There are basic principals regarding plants that are just not evolutionarily possible.
You will never get a land plant to grow in a lake. Even in hydroponics, O2 is critical with plants being exposed to straight water only several times a day or they will drown. The kratkey method makes this especially clear. How can a dead plant reproduce?
This idea that green algae had to mutate for some reason and spring forth all this plant life we have now. Where does green algae grow? Everywhere. You can find it in soil, lakes, statues, anywhere its wet enough, you will find algae. To suggest algae had to change at all is simply preposterous. Common genes don't mean anscestry, it means they are plants.
Thank you MagicAntReal your time and this great debate as well as everyone who took the time to read and follow our points.
Thanks for the debate Con; it's been real.
I think we can both agree that plants are in fact awesome and that more people should study them.
I will echo Con's attempt "to be clear" and quote Con saying that "the definition of plants speaks for itself."
Therefore, the evolution of anything included in Viridiplantae, which includes green algae, should be considered.
1. The origin of the first living single cell and its precedence to single-celled cyanobacteria (blue-green algae).
2. The cyanobacterial origin of PsbO, a protein that both Pro and Con agree is essential to photosynthesis for Viridiplantae.
3. The cyanobacterial origin of plastids, which are plant organelles, included in all Viridiplantae.
4. The monophyletic (common evolutionary ancestor) origin of all green plants, which necessitates plant evolution.
Con remarks on my source:
"The study cited is simply a study for identifying and putting together a phylogenetic tree."
For readers who may not know, phylogenesis is "the evolutionary development and diversification of a species or group of organisms," so Con's attempt to mitigate my source's impact only speaks to its precise relevance to this resolution.
Therefore, the study showed the evolution of plants phylogenetically.
"I find it interesting that Pro would cite something along the lines of PsbO as an evidence for the evolution of plants. PsbO (OEE1) is in every single plant because its instrumental to photosynthesis. This is really like saying because all animals have RBC's then they must be related."
I'm glad Con recognizes PsbO's importance, but I'm baffled at Con's logic.
The study didn't conclude that all plants are related because they all have PsbO, rather the authors used "PsbO protein
sequences...from cDNA sequences obtained by reverse transcription–PCR and RACE" to conclude that all plants are related phylogenetically; see for yourself.
"Why shouldn't PsbO change?"
Well, given that PsbO is utterly required for photosynthetic organisms to photosynthesize, photosynthetic organisms are able to avoid constraints to live long enough to reproduce viable, photosynthetic offspring, so PsbO's capability keeps it necessary; besides, the amounts of PsbO vary among organisms, so in that regard PsbO does change.
"Its nice to discuss the commonalities [of all plants]...none of this goes in the way to give us any explanation as to how we got Tracheobionta or Spermatophyta and this has largely been left untouched the entire debate."
I brought this up earlier, but Con dodged it, because Con realized that Con's own definition of plants is *not* exclusive to vascular plants (Tracheobionta) or seed-bearing plants (Spermatophyta).
Con just used big words to reiterate his displeasure for me not including much about stems, roots, and vascularity.
But I will remind readers that Con's definition for plants in this debate includes ALL of the Viridiplantae clade, including ferns (don't have seeds), hornworts and liverworts (don't have seeds and aren't vascular), and green algae (no seeds, no stems, no roots, no vascularity).
If Con wanted to know the origin of *some* of the Viridiplantae clade, then Con should have specified that in the debate's definition of plant...but Con didn't, so I haven't left out anything relevant to the resolution.
Con starts asserting things:
"An evolutionary model would require an answer to what came first, the plant or the seed?"
First of all, plants most certainly preceded seeds, because spores preceded seeds and so did plastids and plant actins, which one can check at my provided sources.
Second of all, an evolutionary model for some Viridiplantae, like green algae, wouldn't need to mention *anything* about seeds, because green algae, even today, has no seeds, Con.
How can you consistently ignore your own definition of plants?
Con asserts more:
"An evolutionary model will have to show that cellular organisms can transform into plants and organize themselves in such a way that they form a meaningful plant."
You mean like the study I provided 2nd round that confirmed the origin of embryophytes (a subkingdom of plants) to be algae?
It exactly satisfies "cellular organisms can transform into plants," and Con just chose to ignore it.
Con, did you really read any of the studies?
Con annoyingly rehashes:
"Pro wants to discuss cell organelles...sure how about discussing root cells and their organelles?"
Sure, right after you show me where green algae have root cells...no wait, they don't have roots, and YOU Con, YOU included them in your definition of plants.
How is Con so unaware of his own definition that does not necessitate roots AT ALL?
Con attempts something:
"Pro did not bother to cite a lab specific instance in which actin function was able to change a plant into another plant."
Yeah, I went beyond that and showed the literal origin of plant actins, and guess what those sources showed...
You guessed it, that plant actins evolved from a common, or monophyletic, ancestor; from ancestors to descendants is plant to plant change, as demonstrated by the study.
Con acts oblivious:
"Pro did not show a change in algae over the hundreds of millions of years we have known it to exist or cyanobacteria for that manner."
How about I showed the direct monophyletic evidence that cyanobacteria spawned spore bearing plants?
Cyanobacteria-->plants is certainly a change, no?
Con adds to his annoyance:
"Its insufficient to say a plant would simply mutate itself so much so that it becomes over time a whole different plant containing roots and leaves and stems...there's simply no evidence for it or Pro happily would have cited it."
It's irrelevant to point out plants containing ROOTS, LEAVES, AND STEMS, because green algae, a member of Viridiplantae, have none of those...NONE; why should I want to cite something not exclusive to the resolution?
Before I get any more frustrated with Con's oblivion, I invite readers to simply check my sources and what I've provided in quotes, and one can clearly see that the phylogentic tree of plants is understood, which means that we've made accurate predictions about plant origins by using evolution as the framework...plants therefore have undoubtedly evolved and we've confirmed predictions with direct genetic evidence, actins, plastids, and PsbO.
Con, for some odd reason, only thinks that seeds, roots, stems, and leaves qualify as plants, but green algae is a plant and has none of these...this is super frustrating for someone trying to follow the definitions of this debate.
I ask readers to vote for Pro, and, to really affirm this resolution, I'm going to quote the source that Con provided 2nd round to teach us the basics of plants.
The *very first* line of Con's source says:
"Plants evolved from ancestors shared with all other organisms on planet Earth."
See it for yourself, and then vote Pro.
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