Alien Biospheres: Part 6 - The Open Plains

[Music] last time we saw the development of the first terrestrial ecosystems within the vast humid forests that cover the supercontinent supported by a warm wet climate of unceasing rain and storms but it's only a matter of time before these stable benign conditions begin to change as the forests fill the atmosphere with oxygen they'll simultaneously take in enormous amounts of carbon dioxide and hydrogen sulfide thus far the levels of these gases have been maintained by the aerobic respiration of animals and by the activities of sulfur metabolizing microbes respectively but the globe-spanning forests may deplete these gases faster than they can be replenished on top of that as the mountains are eroded by acid rain the newly exposed rock reacts with the carbon dioxide to form calcite s' further lowering atmospheric co2 levels since carbon dioxide is a greenhouse gas a decrease in its abundance will lead to an overall cooling of the planet's climate the enormous storms that deliver rain to the center of the supercontinent rely on high oceanic temperatures and even a drop of only a few degrees will be enough to disrupt weather patterns a din that lowered hydrogen sulfide levels slowed the formation of sulfuric storm clouds in the upper atmosphere and the production of the hyper canes that have fueled the growth of the global forests will come to a halt and the inland regions of the supercontinent will be starved of water and thus the forests will dwindle giving way to vast tracts of open prairies and Plains and although the necro fights in malacca forms will return a portion of the carbon and sulfur content of the trees tissues to the atmosphere through decomposition the remainder will become sequestered on the ground as the trees become fossilized effectively removing them from the carbon and sulfur cycles meaning the original atmospheric levels can't be recovered many species may not survive this environmental upheaval and those that do will need to adapt to an entirely different world note however that due to the fact that this transition takes place quite gradually the resulting decrease in biodiversity won't be significant enough for it to qualify as a full-blown mass extinction but don't worry we'll cover those in much more detail in a future episode one of the most obvious changes in this new world will be in the vegetation the once expansive forests will now only exist near the coasts and around lasting sources of fresh water while in drier habitats the trees will be replaced by scrublands of mixed qualified species these plants being significantly smaller than trees don't require nearly as much water carbon dioxide and hydrogen sulfide and so have an edge in the new climate but they're also likely to strengthen their advantage with several important adaptations all chemo fights have a central body which in Xena fights is surrounded by a tough waxy cuticle and in xyla fights is strengthened by rigid support tissues unlike most plants on earth which grow gamma tangia from the tips of their branches chemo fights gamma tangia grow out from the main plant body the leaves grow from a single meristem or region of tissue growth at the top of the plant to maximise their exposure to sunlight however if the meristem is damaged either by being eaten or simply trampled then the plant won't be able to grow new leaves and so will more than likely die for a full-grown tree this isn't a very prevalent danger because the meristem will be too high up to be within reach of any herbivore but for smaller plants the meristem is much more vulnerable one clade of qualified may solve this problem by having the meristem occur close to or even below the ground level which can be achieved by shrinking the size of the plant body with only the large prominent leaves emerging from the soil like all chemo fights these new plants will be capable of asexual reproduction which will let them spread very quickly across the newly opened habitats as the trees disappear possibly forming huge clonal colonies in many areas and when carrying out sexual reproduction and more densely populated habitats the gamma tangia may grow out from the subterranean plant body into long stalks to maximize the dispersal of gametes this clade of qualifiers which I'll call Braca fights will become the dominant ground vegetation across the supercontinent growing anywhere to dry for trees these areas will be somewhat similar to grasslands on earth though since there's no actual grass I'll refer to them using the more general term steppe this new biome will cultivate a completely new assemblage of niches which the recently evicted forest dwelling species will furiously compete among the low first ohms the tiny melaka forms may survive the transition by dint of their extreme diversity and adaptability but the diplom may be doomed to a much slower recovery since they relied on the forests to maintain the high atmospheric oxygen levels they need to attain large sizes and with the forests gone oxygen levels will steadily fall shrinking the domes maximum size and forcing them to surrender the megafauna niches to the Ostia pods the slow and bulky Lacoste raccoons may survive as small generalist grazers relying on their sturdy shells for protection and the desmos chickens may maintain their lifestyle of dedicated Milaca boars the elastomers however are specialized for life in the treetops so as the forests disappear they may be forced to explore new survival strategies the Alaska spend or springy Gladius lets them execute powerful jumps to pounce on prey as well as to leap between branches which makes them a prime candidate for one particular development on earth many arboreal species have independently evolved the membrane of skin or potassium that lets them glide from tree to tree as seen in animals like flying squirrels or flying lizards and even flying snakes while there are some models that posit the gliding can evolve from a ground dwelling ancestor and while there are occasional oddities like flying fish and flying squid the preponderance of all boreal gliders seems to indicate that the most common pathway to the evolution of a potassium is as a means of jumping between trees the Alaska stare for seem very likely to evolve a potassium to augment their already powerful jumps increasing the time they can remain airborne and the distance they can cover in a single bound as well as to provide a degree of safety if they were to fall from a great height acting like a parachute to slow their descent to support a larger potassium the middle pairs of limbs may become longer and broader and outgrowths of the Gladius may extend into the potassium to allow it to maintain its shape without stretched somewhat like the hyper-extended ribs or ossified filaments found in many clades of living and extinct gliding reptiles altering the position of the limbs to influence the shape of the potassium may even allow them to manipulate their trajectory as they glide and if this is the case it seems very likely that one clade may take this development to its obvious culmination while gliding has evolved over a dozen times in the history of life on earth powered flight we're in the animal can remain airborne indefinitely only has four known instances of having evolved with the exception of insects whose evolutionary past a flight isn't fully understood wings have universally evolved from a potassium supported by an elongated and heavily muscled fallen but the elastin does unique physiology may lead to them evolving a rather unorthodox method of flight if the sites of major muscle attachment occurred towards the posterior end of the animal to pull the Gladius backwards it may be more likely for the musculature necessary to power flight to develop around the two pairs of hind limbs while the front two pairs of limbs provide stability and control pitch as unusual as this method of flight is there is some precedent for it in animals on earth as seen in the awesomely weird fossil reptile Ashura Victor X which although incapable of powered flight formed the bulk of its gliding surface with its hind legs while using its front legs as stabilizers reminiscent of the canards on a delta wing aircraft the flying elastic on dolls may begin with a similar configuration of potassium before developing the musculature to generate the lift needed for true flight becoming the first flying animals on the planet to specialized for flight their bodies will need to become more streamlined and so their eyestalks and oral tentacles may shorten to reduce drag efficient flying will also put a huge demand on their metabolism as flight as a very high-energy activity and requires a number of physiological adaptations to sustain first of all the loafers dermis mechanism of passive respiration may not give them the high stamina needed for flying especially with atmospheric oxygen levels declining however these flying alas despondence may overcome this by exploiting a unique quirk of their Anatomy as they fly the contractions of the posterior muscles will cause the Gladius to undulate which successively constricts and expands the lungs pumping air in and out and providing them with more oxygen this can be complemented by evolving specialized breathing muscles and the thorax giving them a system of active respiration similar to that of the Ostia pods and thus enabling much more efficient flight this innovation may coincide with a change in their metabolism all the animals we've seen so far are ectotherms sometimes described as cold-blooded meaning their internal body temperature is almost entirely contingent on the ambient temperature of their environment however the metabolic reactions needed for sustained muscular activity are most efficient at a consistent high temperature which ectotherms can only achieve in sufficiently warm climates and by spending long periods of the day basking in the Sun this constraint means that our last responders will only be able to fly in short bursts if their body isn't suitably warm so to optimize their flight performance they may evolve some form of thermo regulation the ability to modulate internal body temperature to keep it within a metabolically favorable range thermo regulation is often used synonymously with endothermy where an internal temperature is almost always constant only ever varying within a few degrees as is done in mammals and birds but some animals fall between the two extremes of actor therm and endotherm and thus sometimes get called messer therms for example regional endotherms only maintain an elevated temperature within certain metabolically demanding areas of the body some clades of fish like lamniform sharks and tuna he was counter-current heat exchange between blood vessels to warm the areas around the eyes and locomotor muscles ensuring they can function optimally even in cold waters and many flying insects warm up their thorax by rapidly contracting the opposing muscles without moving the wing generating heat in a similar way to the shivering reflex in mammals and birds will discuss thermoregulation in more detail later but something similar to the latter mechanism might evolve in the flying Alaska spondylus specialized muscles within and around the wing membrane may engage whenever the wings temperature drops below a certain threshold decreasing the reliance on warm environments for efficient flying which combined with their active respiration will enable them to sustain prolonged periods of long-distance flight as the first flying animals in the planets history these are last responders will have all the aerial meters to themselves and so may be hugely successful and undergo an explosion of diversity which we'll explore in future episodes let's call them office doctrines meanwhile on the ground below the osteopath will need to find their own way to adapt to the changing landscape one of the immediate pressures imposed by the steppe is that without the cover of the forest vegetation animals will be much more visible and vulnerable to predators encouraging the evolution of new defensive adaptations no longer bound by the dense forest vegetation some herbivores like the mega brackets may respond to increased predation by getting bigger as a large size acts as a deterrent to attackers Plus that comes with the added benefits of an expanded feeding envelope letting them feed on vegetation out of reach of other herbivores and it acts as a method of thermoregulation by increasing the amount of body heat they generate but attaining an especially large size requires several key adaptations first of all our old friend of the square-cube law means that doubling an animal's size will increase its volume and therefore its weight by a factor of eight and to support the sexter weight the legs will need to become 2.8 3 times thicker as the creature gets larger and larger the legs will eventually become so thick that it will be impossible to maintain the enormous amount of muscular energy required to move them having a skeleton helps a great deal in increasing maximum size as bones are much better at withstanding compressive forces than pure muscle but optimizing the weight-bearing potential of these bones requires a change in their arrangement most of the osteo pods we've seen so far have limbs that are splayed out to the side of the body like many amphibians reptiles and arthropods on earth this sprawling posture provides a wide stable base that reduces the chances of falling over but it can't support a great amount of weight although in our alien planet this constraint is slightly alleviated by the low gravity such that the native fauna may support themselves were the more splayed posture than animals of equivalent size would need on earth but as the animal gets heavier the most efficient way to support the extra weight is for the limb joints to move closer to the sagittal plane or central line of the body which reduces the amount of muscle power needed to stay upright and relieves the torque imposed on the joints beyond a certain weight for the animal to be able to stand at all the legs need to be positioned directly under the body and perpendicular to the ground on earth this development occurred independently among ARCA soars and stem mammals which would later allow both groups to achieve in men's sizes so the same innovation might occur among the steppe dwelling Megillah brackets beyond the biomechanical constraints a larger body also needs a greater amount of food so an animal's maximum size will be contingent on the abundance of food in its habitat this may preclude many of the larger species from colonizing the sparse inland regions towards the center of the supercontinent but the areas along the edges of the coastal forests may be rich enough in vegetation to fuel the growth of the biggest animals yet to evolve we'll call these giant mega brackets titanoboas once they're established as the dominant herbivores different clades of titanic pods may specialize for different modes of feeding the forest dwelling Megillah brackets from which the titanic odds descend were primarily browsers using their elongated pedipalps to reach for high vegetation one clade of titanic odds may retain similar feeding behaviors taking advantage of their enormous size to feed on the leaves at the very tops of the trees and since no other clade can rival them in size they'll have these browsing niches all to themselves free from competition these forms which we'll call Procera pods will thrive in areas where stands of trees grow alongside patches of open plains such as gallery forests that grow around large rivers and lakes but in areas with fewer trees the titanic pot will need to adapt to feed almost exclusively on the Braca fights and thus change their feeding habits to become dedicated grazers these species won't need to reach upward for food as so may have shorter legs and smaller pet Apelles indiscriminantly stripping the Braca fights to the ground like giant living lawnmowers will call these creatures barrow pods together the priscila pods and barrow pods will dominate the niches of large herbivores but the plains also offer niches for smaller more adaptable animals although most plaited ants are adapted to life in the trees some of the more generalist species may be able to eke out a living on the steppe as the forests disappear which may give rise to a claim of permanent ground dwellers which will dub theer's just like the Megillah brackets the adapt afia's will be more exposed to predators on the step and so will need to invest in some form of defense competition from Titanic odds may prevent them from reaching large enough sizes to offer substantial protection but the adapt fears can instead use their speed and agility to outrun their predators once again though sustained activity is most efficient at high body temperatures so just like the office doctrines the adavi has may evolve a means of thermoregulation perhaps investing in full-fledged endothermy to give them high energy levels throughout the whole day however endothermy does come with a drawback a constantly high metabolism needs a lot of food to maintain whereas ectotherms like crocodiles can go for over a year without a meal endotherms are required to feed much more often with extreme cases like the American pygmy shrew needing to eat three times their own weight in food every day fortunately for the adapt earthy is though the step offers an abundance of food and the adaptations they inherit from their placard on ancestors make them well equipped to exploit every available source of nutrients the forest dwelling plant had aunts had a varied diet of mixed plant matter in addition to malacca forms and other assorted small prey one clade of adapt athere's may remain adaptable generalists but adopts two additional feeding behaviors firstly scavenging carrion represents a rich source of protein to supplement their diets so these are Dafa Thea's may therefore assist the net crow fights in Melaka forms and keeping the steppe cleaning of caucuses it's important to note that a bubble relatively small body size relying on scavenging alone for food becomes impractical since carrion rarely occurs in quantities sufficient for a large animal to live on exclusively so most scavengers will still actively hunt prey if carrion isn't readily available scavengers often have keen senses to help them detect food over long distances so in arid a for Thea's the scent receptors lining their spiracles may expand into complex or factory chambers with a large surface area to increase their sensitivity to help them reach inside the bodies of caucuses their pedo parts may become slender and Grace Isle tips with taste receptors to probe for fresh meat and a saw like arrangement of serrated Klaus will help them tear chunks of flesh from within another feeding behavior these adapt a theist might adopt is a vivoli eggs are rich in essential nutrients and the steppe will be littered with the ofd k of megafauna like the titanic pods in addition to helping them locate carrion their powerful sense of smell may also assist in finding widely scattered nesting sites even letting them detect eggs that are buried under several centimeters of soil however if their slender pedipalps are adapted for cutting and processing meat they won't be very effective at digging so to help them on earth buried eggs the feet on their front Walking limbs may become stronger and broader like spades while still considered omnivores these feeding behaviors may increase the prevalence of meat in their diet and therefore most species in this clade will qualify as mezzo carnivores animals who gain between fifty and seventy percent of their energy from meat and subsist on plant matter for the rest let's call these adaptable creatures gyro Chiron's but the most plentiful source of food on the step is the virtually inexhaustible colonies of Braca fights which a second clade of a daffa the--is may specialized to feed on exclusively their broad teeth previously adapted to cope with a variety of mix foliage will make short work of the Braca fights soft waxy leaves and spongy bulbs and with sufficient food in the metabolic machinery for high levels of activity these herbivorous Siddarth ears can further invest in speed possibly undergoing adaptations for cursorial locomotion cursorial animals are those that are specialized for high speed or long-distance running which is associated with a number of common developments first of all curse or reality is strongly correlated with an erect limb posture like we saw in the titanic pods which not only allows the limbs to support a larger body size but also to transfer more force to the ground for more efficient running so our herbivore Siddhartha's may undergo a similar shift in posture secondly cursorial locomotion is made more efficient by increasing stride length or the distance between footfalls which can be extended by making the limbs longer and increasing the range of motion of the joints luckily for the ADEA fears they already have long flexible limbs used by their arboreal ancestors to climb trees and reach between branches making them somewhat pre-adapted for coastal reality another way to increase stride length is to alter the posture of the foot the foot structure of vertebrates on earth can be broadly divided into three forms plantigrade walkers keep the foot flat against the ground which provides stability and effective distribution of weight digitigrade walkers on the other hand walk on their toes with the heel raised off the ground while ungulate great walkers stand on the tips of their toes which are usually elongated and adapted into hooves which is why in many odd-toed ungulates what looks like the lower leg is actually a single hyper extended toe cursorial locomotion favors the latter two forms as they essentially serve to add the length of the foot to the stride length while the skeletal comparisons between vertebrates nastya pods aren't exactly equivalent these cursorial adapt afia's may evolve longer feet with only a single point of contact with the ground and they're hooked claws once used for grabbing tree branches may become Bonta and hoof like to give them purchase against the substrate finally if coastal reality benefits from an elongated flexible spine in animals like the cheetah the spine can bend far enough forward for the front and hind limbs to overlap which allows for the entire length of the body to contribute to stride length as the spine extends the herbivorous adapt athere's may mimic this by evolving a longer more flexible body with more space between the limb girdles all of these adaptations will make these animals which will call lepto pods some of the fastest animals on the steppe but they won't be the only animals to specialise for speed with the plains accommodating such an abundance of herbivores it's inevitable that new predators will evolve to hunt them before the climate changed the dynamic nathan's were at the top of the food chain but as the steppe spreads the dense vegetation that they rely on for ambush hunting will disappear although they're easily large and powerful enough to hunt prey like the Titanic odds and lepto pods their great size makes them very easily spotted out in the open so ambush tactics are no longer a viable option and the fused robust limb girdles they have in common with also nests Qian's can't articulate very far so they may be prohibited from specialized for curse or reality without the speed to keep up with fast-moving quarry the dynamic Nathan's may not be able to adapt for predatory niches on the open plains only surviving within areas of vegetation dense enough to conceal them on the other hand the dromio pods have already evolved a limb orientation suited for pursuit hunting and so are in some ways pre adapted to hunt swift prey on the steppe like the Lecter pods the active lifestyle of the dromio pods may lead to them convergently evolving thermo regulatory mechanisms but unlike the latter pods whose activity levels remain more or less constant as they feed on the bountiful Braca fight throughout the day the dromio pods will oscillate between periods of high activity when hunting and long spans of low activity between hunts to make thermoregulation more economical they may adopt another form of Mesa thermy facultative endotherms only regulates their temperature under certain energetically favorable conditions for instance hummingbirds have the highest metabolisms of all vertebrates letting them power the extraordinarily rapid beating of their wings for extended periods but when resting or in the absence of sufficient food the energetic demands of thermoregulation are no longer practical or necessary to maintain and so their internal body temperature plummets likewise our dromio pods may only thermoregulate when hunting for optimal performance while between hunts or when food is scarce they may cease thermoregulation to conserve energy to augment their already impressive speed the steppe dwelling dromio pods may undergo similar cursorial specialization as to the latter pods including an erect posture elongated limbs and a flexible spine but they may gain a further advantage from one particular adaptation all osteo pods have one pair of peda pulps used to sense the environment and to handle food and four pairs of walking legs inherited from their soccer pod ancestors among terrestrial body plans on earth the number of limbs present is wildly variable ranging anywhere from zero to multiple hundreds while the minimum number of legs needed for a cursorial animal is only to having additional legs increases the animal's stability by creating a wider base however extra legs require extra energy to maintain the nests very musculature with diminishing returns for every additional pair of legs on earth terrestrial megafauna niches are exclusively occupied by vertebrates almost all of which have four limbs so it's difficult to know how viable a large cursorial species with more than four walking limbs would be but it seems likely that to maximize speed and minimize unnecessary energy expenditure the steppe dwelling dromio pods may evolve to run on only six legs rather than eight initially these dromio pods may use their front most pair of walking legs along with their pet aparts to catch and restrain prey over time these legs may lose their locomotive function entirely and be held permanently off the ground giving them the freedom to be secondarily adapted to aid in manipulation as happened on earth and animals like mantids dinosaurs kangaroos and australopithecines Harris van take author of the blog and Farrar and biology and allied matters has coined the elegant term sin tourism to describe this condition from here the limbs may become clawed arms to latch onto fast-moving prey while the peda palps may sharpen into fang-like points to deliver the killing blow this innovation will simultaneously give them the speed and maneuverability to keep pace with the letter pods and the weaponry to tackle prey as large as the Titanic odds these specializations may go along with a shift in diet unlike the more generalist year occurrence most of which are mezzo carnivores some of these step dwelling dromio pods may evolve into hyper carnivores animals that obtain over 70% of their energy from meat this suite of new adaptations will make these dromio pods the top predators of their day I'll call them Annika dance all of these clades represent only a tiny fraction of the diversity that the steppe will support but they'll comprise the most populous and successful groups over the 30 million years or so following the retreat of the global forests but away from the equatorial Plains the disruptions in the planet's climate will have far greater ramifications felt not only on land but also in the ocean in the next episode we'll see how some of our terrestrial species exploit the newly vacated aquatic niches and undergo the unprecedented transition back into the war thanks to campfire for sponsoring this episode if you've got your own world building project whether it be an alien planet a medieval fantasy world or an alternate history camp FirePro can be a big help to keep things organized it has pages for maps timelines and encyclopedia entries to manage your world's geography history and items of interest as well as tools to keep track of characters relationships plot threads and other narrative elements best of all is the brand-new world building pack an expansion that includes entries for languages religions magic systems species and basically anything else you could possibly want to catalog you can get campfire Pro and the world building pack for a one-time purchase through the link in the description thanks also to the fans over on discord who submitted fan art for this episode links to the main server and the fan art server in the description and a massive thanks to all the patrons whose continued support makes videos like this possible thanks for watching and I'll see you in the next video you [Music] you

Channel: Biblaridion

Views: 397,595

Keywords: Speculative biology, Worldbuilding, Alien biospheres

Id: VwRYTgNE57Q

Length: 27min 53sec (1673 seconds)

Published: Wed May 06 2020

Reddit Comments

[u/TheInfinitePrez]

I’ve also fallen in love with this series. As another hard sci-fi world builder I find this incredibly inspiring!

[u/ixiox]

S Q U I D B I R D S

S P I D E R G E P A R D

[u/CoatiNasu]

Thank you SO MUCH for presenting me to this series. It's so fun to see such detailed world building taking place and it also reminds me of the better school days.

This is legitimately making me want to open a chemistry book again

[u/SchwefelKamm]

Just saying, a big mistake he made was turning a gliding creature into a flying one. That doesn't happen, instead it's parachuting.

Otherwise, its good