#if I wanted predatory seeds I'd go on bittorrent. ayoooo

[captious-solarian]

This is so cool

(Guy who has only ever seen protists voice:) Getting a lot of protist vibes from this. You get wildly different strategies, from basically-plants to parasitic to predatory to changing by life stage.

SpecBio concept #4: Plantworld

A planet resembling Earth in its late Archean state (higher temperature, no free oxygen, dense atmosphere, extensive salty oceans, thick coat of carbon dioxide), perhaps more tectonically stable, extensively seeded with Earth plants and bacteria. Not a single animal or fungal species is brought.

The first green settlers struggle to get a hold on the barren continents, in absence of fungi to erode bare rock and worms to aerate the ground. But some ground is more hospital than other, the first layer of debris provides soil for the survivors, and eventually plant life starts to grow properly.

For many millions of years the plants thrive, thanks to the abundance of carbon and water, the higher temperatures, and the lack of oxygen to interfere with carbon fixation; but eventually oxygen starts piling in the atmosphere, gigatons of carbon are locked into wood and buried debris (to be released in pulses only when wildfires burn out uncontrollably), and the diminished greenhouse effects starts to cool down the planet sensibly. The forests start to shrink.

There’s an obvious niche to be exploited there. Parasite plants without chlorophyll exist on Earth right now, such as the very unfortunately named broomrape. They’ve always thrived on Plantworld in many lineages, with the bounty of hosts to exploit, but now they can do one better: they find out how to secrete acids and enzymes to break apart cellulose, much like fungi did on a forgotten planet, and start consuming the vast dead biomass.

The decomposer plants scatter their pollen and seeds to the wind (no animal disperser to exploit), gliding away on wing-blades like maple seeds, but why stop there? If they gather enough energy, they can manipulate osmotic pressure inside the seeds to move the blades, until they can flap them like wings. This consumes enormous amounts of sugar and oxygen: each plant can afford very few seeds. The strands of turgid cells become analogues of muscles, and soon Planetworld’s forests are abuzz with little flying seeds, flying as far as possible from the mother plant to avoid competing against their own kin.

Each incremental improvement to fitness suggests others. If you sharpen your chemical senses, you could detect the places were there is fewest competition… if you steal back some photosynthetic pigments from your prey (which are but light detectors, after all) you can repurpose them into crude eyes to look for better ground… if you can move your wing-flaps, you can move them on the ground to place yourself in a better germinating position.

Absorbing matter through roots is agonizingly slow for these increasingly energic parasites. It would be much quicker to take food in bulk. The flying seeds secrete powerful saliva-like enzymes to degrade the matter on which they germinate; they use their osmotic muscles to grind shell-plates against each other like tiny jaws; they develop internal specialized glands… And eventually they discard the roots at all, which have lost their use. Why bother growing into a plant form? You can just stay a flying seed all your life, and sprout your flowers directly there. Actually, now that you’re so nimble, you can just seek out your mates directly.

Half a billion year later, Plantworld has a rich biosphere full of animal life; swift-footed grazers and silent ambush predators, swarming minute plankton and giants feeding on them by the millions, industrious hive-builders and devious endoparasites; and perhaps some creature with inquisitive brains and dexterous hands who is in for a big surprise or two when they finally chart the history of life on their world.

SpecBio concept #3 (children falling from the “sky”) SpecBio concept #2 (liquid brain, chemical memory) SpecBio concept #1 (double silicate biosphere, one hot, one cold)