Spore Full Game

[Geralyn]

Inbiology, a spore is a unit of sexual (in fungi) or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions.[1] Spores form part of the life cycles of many plants, algae, fungi and protozoa.[2] They were thought to have appeared as early as the mid-late Ordovician period as an adaptation of early land plants.[3]

Bacterial spores are not part of a sexual cycle, but are resistant structures used for survival under unfavourable conditions.[4] Myxozoan spores release amoeboid infectious germs ("amoebulae") into their hosts for parasitic infection, but also reproduce within the hosts through the pairing of two nuclei within the plasmodium, which develops from the amoebula.[5]

In plants, spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. In some rare cases, diploid spore is also produced in some algae, or fungi.[6] Under favourable conditions, the spore can develop into a new organism using mitotic division, producing a multicellular gametophyte, which eventually goes on to produce gametes. Two gametes fuse to form a zygote, which develops into a new sporophyte. This cycle is known as alternation of generations.

The spores of seed plants are produced internally, and the megaspores (formed within the ovules) and the microspores are involved in the formation of more complex structures that form the dispersal units, the seeds and pollen grains.

In common parlance, the difference between a "spore" and a "gamete" is that a spore will germinate and develop into a sporeling, while a gamete needs to combine with another gamete to form a zygote before developing further.

The main difference between spores and seeds as dispersal units is that spores are unicellular, the first cell of a gametophyte, while seeds contain within them a developing embryo (the multicellular sporophyte of the next generation), produced by the fusion of the male gamete of the pollen tube with the female gamete formed by the megagametophyte within the ovule. Spores germinate to give rise to haploid gametophytes, while seeds germinate to give rise to diploid sporophytes.

Heterosporous plants, such as seed plants, spikemosses, quillworts, and ferns of the order Salviniales produce spores of two different sizes: the larger spore (megaspore) in effect functioning as a "female" spore and the smaller (microspore) functioning as a "male". Such plants typically give rise to the two kind of spores from within separate sporangia, either a megasporangium that produces megaspores or a microsporangium that produces microspores. In flowering plants, these sporangia occur within the carpel and anthers, respectively.

Fungi commonly produce spores during sexual and asexual reproduction. Spores are usually haploid and grow into mature haploid individuals through mitotic division of cells (Urediniospores and Teliospores among rusts are dikaryotic). Dikaryotic cells result from the fusion of two haploid gamete cells. Among sporogenic dikaryotic cells, karyogamy (the fusion of the two haploid nuclei) occurs to produce a diploid cell. Diploid cells undergo meiosis to produce haploid spores.

Under high magnification, spores often have complex patterns or ornamentation on their exterior surfaces. A specialized terminology has been developed to describe features of such patterns. Some markings represent apertures, places where the tough outer coat of the spore can be penetrated when germination occurs. Spores can be categorized based on the position and number of these markings and apertures. Alete spores show no lines. In monolete spores, there is a single narrow line (laesura) on the spore.[8] Indicating the prior contact of two spores that eventually separated.[3] In trilete spores, each spore shows three narrow lines radiating from a center pole.[8] This shows that four spores shared a common origin and were initially in contact with each other forming a tetrahedron.[3] A wider aperture in the shape of a groove may be termed a colpus.[8] The number of colpi distinguishes major groups of plants. Eudicots have tricolpate spores (i.e. spores with three colpi).[9]

In fungi, both asexual and sexual spores or sporangiospores of many fungal species are actively dispersed by forcible ejection from their reproductive structures. This ejection ensures exit of the spores from the reproductive structures as well as travelling through the air over long distances. Many fungi thereby possess specialized mechanical and physiological mechanisms as well as spore-surface structures, such as hydrophobins, for spore ejection. These mechanisms include, for example, forcible discharge of ascospores enabled by the structure of the ascus and accumulation of osmolytes in the fluids of the ascus that lead to explosive discharge of the ascospores into the air.[13]

The forcible discharge of single spores termed ballistospores involves formation of a small drop of water (Buller's drop), which upon contact with the spore leads to its projectile release with an initial acceleration of more than 10,000 g.[14] Other fungi rely on alternative mechanisms for spore release, such as external mechanical forces, exemplified by puffballs. Attracting insects, such as flies, to fruiting structures, by virtue of their having lively colours and a putrid odour, for dispersal of fungal spores is yet another strategy, most prominently used by the stinkhorns.

In the case of spore-shedding vascular plants such as ferns, wind distribution of very light spores provides great capacity for dispersal. Also, spores are less subject to animal predation than seeds because they contain almost no food reserve; however they are more subject to fungal and bacterial predation. Their chief advantage is that, of all forms of progeny, spores require the least energy and materials to produce.

Spores have been found in microfossils dating back to the mid-late Ordovician period.[17] Two hypothesized initial functions of spores relate to whether they appeared before or after land plants. The heavily studied hypothesis is that spores were an adaptation of early land plant species, such as embryophytes, that allowed for plants to easily disperse while adapting to their non-aquatic environment.[17] [18]This is particularly supported by the observation of a thick spore wall in cryptospores. These spore walls would have protected potential offspring from novel weather elements.[17] The second more recent hypothesis is that spores were an early predecessor of land plants and formed during errors in the meiosis of algae, a hypothesized early ancestor of land plants. [19]

Whether spores arose before or after land plants, their contributions to topics in fields like paleontology and plant phylogenetics have been useful.[19] The spores found in microfossils, also known as cryptospores, are well preserved due to the fixed material they are in as well as how abundant and widespread they were during their respective time periods. These microfossils are especially helpful when studying the early periods of earth as macrofossils such as plants are not common nor well preserved.[17] Both cryptospores and modern spores have diverse morphology that indicate possible environmental conditions of earlier periods of Earth and evolutionary relationships of plant species.[17][19][18]

This page is intended to be a sort of liner notes for my contributions to Spore. It's a place for me to write up miscellaneous development comments about the parts of the game I worked on, while they're still fresh in my mind. I think the game had over 80 people working on it towards the end, and it was in development for more than 5 years, so basically everything in the game was touched by more than one person and was a team effort. Given that, I will strive for inclusion and accuracy, and I will only talk about systems to which I made substantial contributions. If I've left somebody out or made a mistake, I apologize; please email me and I'll correct it immediately.

A Brief Note on Game Credits This page could be seen as augmenting the game credits[1], like what you'd get if you could click on the names to get more information. I think credits are very important for game developers, our industry, and the art form[2]. Although assigning credit is a bit tricky because large-scale game development has a lot of subtle, overlapping, and often blurry responsibilities, I still think it's interesting to have rough descriptions and color commentary of the major things each person worked on. This is my attempt at this for my contributions, before I forget the details. I hope more developers put up pages like this for the games they work on.

Almost all of my contributions center around the creatures, and helping to bring them to life for players. My favorite moment in the game is when you first attach a leg or arm or mouth to the torso in the creature editor, and your creature comes alive and turns to look at its new limb or roars with its mouth. It's great to watch players be delighted by something they just created.

In most cases I'm limiting my discussions to the specific code and tools that I contributed to directly, which leaves out descriptions of a lot of the incredibly important and groundbreaking work other people did on neighboring code, whether higher level, more player facing aspects of the code, like user interface and gameplay, or lower level systems stuff like resource management, threading, rendering, and the like. It also leaves out the contributions of the awesome artists who used the [sometimes cantankerous] tools and systems.

The first thing I worked on when I started on Spore (in October, 2003) was the creature skin. Unlike games with fixed characters, like a James Bond or Lara Croft game, or games with parameterizable meshes, like the Sims or City of Heroes, Spore has to generate the entire mesh on the fly as the player makes the creature. While a typical game's fixed or parameterizable character mesh might be worked on for days in a 3D modeling tool like Maya by a professional game artist, Spore needs to regenerate the skin in real-time as the player deforms the torso and attaches and detaches limbs. I chose a blobby implicit surface (sometimes called metaballs) to represent the skin.

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