User blog:Cerne/Update (part 2)

And I’m back again to publish Part 2 of my superficially huge conworld update.

…superficially? What was superficial about the six pages of text I published last time? Well, like I said last time, the update was supposed to be rudimentary. While it was an update, I felt – for the most part – that it was spent explaining ideas I hadn’t really decided upon and suggesting what I could do with them, rather than describing what I had already decided to do in smaller point-form detail. I still feel this latter approach would be more successful in garnering outside interest in this personal endeavor, but then…with me it is more a matter of taking what you get or not taking at all. To put it one way.

I set out to make my entries as simple as I can but then initial attempts grow larger as I type them and continued or repeated attempts kinda go nowhere. In this instance, while Part 1 had a lot to do with gathering external sources and summarizing them in ways that were relevant (to me), Part 2 has more to do with accumulation of ideas over a longer period of time. Part 1 complementary data came primarily from online sources and were borne from necessity, and Part 2 data came from hard sources like books and were accumulated over time as I found out about them.

The one exception to this would be the first bit of Part 2, since it has to do with inorganic chemistry and physics, both of which I am not well-versed with and therefore are more likely to be complemented with sources whenever I happen to need them. As such, the first bit of Part 1 couldn’t be typed until now. How it turns out remains to be seen (as I type this) but you may already know what to expect by now.

NOTE: The above paragraph in the intro, which has been re-edited, applies to the entry I published right before this one. See the intro for that entry for more information.

With that said, let’s get on to the actual entry.

……

I am going to describe the progress I made with that fifth macroscopic kingdom of life forms in a following entry, as what I have typed for it is way too extensive for this entry. However, there is a second group of photosynthetic plants on my conworld that I will describe in some detail here.

We think of most plants on Earth as "green" plants because, well, they are green. They absorb enough light on the blue-green end of the visible spectrum that the highest wavelength they can stand to reflect is the colour green. Ergo, green becomes a sort of neutral colour for plant life on Earth.

Not so on this planet, where the need to absorb more wavelengths of light requires that a colour lower on the visible spectrum needs to be reflected.

Furthermore, and likely for this reason, all members of the designated kingdom Plantae on Earth are descended from blue-green algae. But there are also "red" algae which have not yet been able to colonize the land. The reason for this is more likely to be due to competition with blue-green algae than to their reddish colouration; red algae owe their colour in part to their phycobiliproteins which are what all algae and terrestrial green plants use to capture light for photosynthesis. Red algae belong to a separate domain of life but are still recognized as "plants," or more appropriately phototrophs, because they still have chloroplasts and thus still partake in photosynthesis.

Different-coloured algae also exist in my conworld but I've decided to go further with them and make some of them terrestrial. Many species may even be vascular but that latter ambition is more conservative because it depends on whether they really need to be vascular or not in order to do what I want them to do. A while back, I learned about a chemical process in which sulphur could be used to convert sulphuric acid back into sulphur dioxide and water.

Here it is: S + 2 H2SO4 --> 3 SO2 + 2 H2O

If some forms of algae - upon becoming terrestrial - were able to withstand acid rain long enough to neutralize it and expel the SO2, they could go on to photosynthesize the left-over H2O and turn it into sugars.

I should probably explain here that acid rain may more-or-less become a fact of life for a while on my conworld, due to the increased volcanism that may be going on. Given that the planet already has a lot of cloud cover filtering out a lot of ultraviolet rays from its sun, having a red colouration will not make life a whole lot easier for a plant. Photosynthesis may slow down and the plant may need to turn to additional processes like chemosynthesis to produce the necessary energy and chemicals it requires. Luckily, due to their hypothesized resistance to acid rain, "red plants" may out-compete green plants practically everywhere except in the places that are not prone to acid rain. I may use this to explain two things: 1) why the ground cover, instead of being green grass, is composed of intertwining mats of reddish leafy clubmoss-like things; and 2) why green plants all have woody stems and live only in the interior of landmasses.

So there we go. Green plants and red plants, both existing together. There may be other types of phototrophs as well but that is what I have for the time being.

……

When designing creatures and plants for my conworld, I always tend to concentrate most of my attention on vertebrates. They constitute everything I thought was important to my conworld and everything that had to do with it. To this day, invertebrates are still very poorly represented. Lately, however, I have been thinking about how much of what I want to present about my conworld actually depends on their existence. They do make up very important parts of many ecosystems that I like to focus on when describing my conworld; they are predators as well as prey, and they represent much of the more unusual, exotic, and truly alien aspects of my conworld. They are a major food staple for one of my concultures, and they are also a major threat to that conworld. They range from microscopic to well over ten feet long and nearly half a tonne in weight. So it would be a huge disservice to underrepresent them.

If I am going to represent them fairly and accurately, then, I should start with where they fit in my conworld's natural and evolutionary history.

I will say right now that invertebrate evolution on Earth is currently fraught with controversy and inconclusion. My general understanding is that the main difference between protostomes and deuterostomes, the two primary groups in bilaterian phylogeny, occurs during embryonic development: the blastopore in deuterostome embryos becomes the anus and it "tunnels" through the embryo, becoming the mouth on the other side, whereas in protostome embryos it becomes the mouth and pretty much does nothing. In some invertebrate embryos the blastopore closes mid-way and you wind up with a looping gut, with the anus being right underneath or above the mouth, but at other times there is a "blind gut" that has no anal opening at all.

Phylogeny within the protostome group is no less confusing. Ecdysozoans - invertebrates with an exoskeleton that is shed and regrown regularly - are one group. The other group traditionally consists of the placozoans (flatworms) and a fourth group known as Lophotrochozoa, a sort of portmanteau of its two constituent groups Lophophora and Trochozoa. All remaining invertebrates can be split into these groups.

I am pretty much summarizing Wikipedia here, though. There are other ways of classifying invertebrates and the groups they consist of. Traditionally, invertebrates could also be classified into Eucoelomata,'' Pseudocoelomata, and Acoelomata''. More recently, I came across yet another classification scheme with groups that were rearranged and had different names. Unfortunately, however, I posted my version of that scheme on Xhin's Gametalk X.0 and the thread it was on got pruned before I could back it up elsewhere.

As of this day I no longer classify the invertebrates in my conworld in the same way that invertebrates on Earth are classified. The group is paraphyletic, anyway, so I don't know why I should bother.

First things first: my conworld doesn't have ecdysozoans. It has segmented acoelomate flatworms with an outer covering made with a soft carbon-based polymer. These creatures diverged from their flatworm ancestors when they adapted to living deep underground. They are also "pan-aerobic," meaning they only inhale gases they can do something with on a chemical level. Whether this will be an ancestral or derived trait in the invertebrates as a whole, I do not yet know, but for these guys in particular it means they need to breathe hydrogen because it will be the only readily-available gas they will be able to do something with. I should also mention that these segmented flatworms share their ancestor's ability to be split into multiple medio-lateral sections and still survive and re-grow, and they have carried this ability well into the macroscopic world, but they have gone even further. Rather than re-grow each body segment, they utilize an alternation-of-generations reproductive strategy whereby smaller "post-larval" forms emerge from each segment and are able to reproduce sexually.

While I am at it, I might as well say that the Earth taxon Protostoma doesn't exist, either. I mean, if they are all going to be flatworms anyway, what's the use? Deuterostoma will also be renamed.

Alongside the segmented flatworms, there will be another group of flatworms with tentacled mouths that may resemble elongated squid and cuttlefish. They may take a parallel yet opposite evolutionary path to the renamed deuterostomes by also evolving a second blastopore but then turning it into an anus. I suppose this could have happened because these worms needed to excrete waste from their food whereas their ancestors never needed to. Perhaps these worms were now eating bigger animals.

This second divergent group of flatworms originated in the water - unlike the first divergent group - but they eventually evolved toward living on land. A variety of different forms emerged after that, from the giant antlion-like "snare worms" to the tiny gliding "leech worms," and everywhere in-between.

Going back to the first divergent flatworm group, I am planning on making them primarily herbivorous but some post-larval forms may be carnivorous. In their asexual larval form these worms will have one set of legs for each segment, sort of like a centipede does, while the post-larval stage will have multiple sets of an indeterminate number. I also plan to have this group of invertebrates develop a symbiotic or co-evolutionary relationship with the radiosynthetic autotrophs I brought up earlier and will bring up in the following entry.

All in all, I am picturing ecosystems that are not too much unlike those of Earth. Invertebrates in my conworld will be diverse enough to play the same kinds of roles that invertebrates on Earth do, though due to there being no flowering plants nor will there be any invertebrates resembling bees or butterflies. I will finish this section by saying I think I will use the names Eucoelomata, Acoelomata and Pseudocoelomata after all; the first will be used in place of Deuterostoma, the second will be used for the adjoining paraphyletic flatworm group, and the third will be used for the second group of divergent flatworms within the Acoelomata group.

......

That will be it for now. There were actually supposed to be three more segments in this entry but they each eventually became so long that I decided to put them in later separate entries. I may even put them in bacl-to-back, if I have enough time. They're all typed and ready to go so it's not like I am trying to be optimistic about something I have not yet completed, like I have so many times in the past. And no, this wasn't one of those accumulative things. I managed to type 11,000 words in four days this time. It's just that I've been...busy this year. Quite a bit has happened, and a lot will hopefully happen in the very near future.

Anyway, I'm gonna end here. Now. Thanks for reading.