Forgive me for being ignorant on this, I’m an art major not a bio major; but I was under the impression that speciation was defined by an inability to produce offspring with one another. Can you explain how speciation is determined outside of those parameters? as seen in your post about Pitcher Plant Fucking. (Love the blog btw. As someone who is fascinated by both botany and mycology it’s nice to have this stuff on my feed)
there are….a lot of ways i could address this question. ive rewritten my answer to this several times and it’s…very hard to explain. the short answer is that i was also taught about The Fuck Line Between Species, and for the most part…it’s not too bad of an idea. like, it’s a pretty good explanation of why like, a dog and a horse can’t make a baby. they’re different species. but it turns out that as the species get more closely related- and i only learned about this like, this year- the line blurs. they look like different species, and they act like different species…but they Can Fuck. this is especially a problem in plants. when this comes up, biologists sometimes attempt to solve the problem by just kinda…widening the constraints a little into what’s called a ‘species complex’, which can encompass a lot of definitions depending on the species in question, including instances like hybrids between species (like wolf/dog hybrids and waaaayyy more nepenthes species then should happen) as well as a ton of other niche genetic instances.
i learned this really cool story at the first botany conference i went to earlier this summer, talking with a dude at the american fern society booth that explains this really, really well. it goes like this:
in the 1950s, the fern community had a problem. there was a group of ferns in the eastern US called the Aspleniums family. people had tried to think of them as all distinct species, but some were fertile and others were sterile and there were like, different chromosome numbers happening and everyone was generally very confused, because sometimes they looked closer to each other and sometimes they looked very different. people suspected that they might be hybrids, but hybrids of what exactly?
in 1954, there was a botanist at the university of michigan named Warren Herb Wagner who decided to figure it out. he determined in a paper called “Reticulate Evolution In The Appalachian Aspleniums” that out of the 9 species described (wagner actually calls them ‘entities’ at certain points in the paper, which i think shows how far the idea of ‘species’ was being thrown out the window in this case), there were three primary species that showed the extremes of certain traits, and singled them out as the Main Fuck Machines. all the others were determined to be hybrids, in some degree, of the three of them.
how can u get 9 species out of 3? well it turns out that not only were the 3 main species fucking among themselves, but the offspring of those species were fucking with the other parents, and with the other hybrids, etc etc, producing some that were fertile, some that were fertile but had a weird chromosome number, and some that were sterile, resulting from the fertile plants and the mutant fertile plants fucking.
side note: i love this paper bc it just like…throws everything i was taught in high school bio out the window. for example, i was taught that all hybrids of species were inherently sterile, and that’s how we knew that the parents were different species. wagner responds to this with the line, “…sterility per se is no longer the sole
signpost of hybrid origin. Indeed, the
best-known fern hybrid, Asplenium ebenoides (A. platyneutron x A rhizophyllum), though usually sterile, occurs as a
fertile form in one large population in
Alabama.” (bc why not, you know? again. why the fuck not).
so wagner now had sorted these plants into three categories of normal, kinda weird, and Very Weird. he did some hybridization breeding experiments as well as studying them on a cellular level, and came up with a way off illustrating the whole ordeal that’s used in a lot of biological contexts today. it’s called “the Asplenium triangle”. here’s what it looked like in the original paper:
now for the life of me, i cannot find a better illustration of this…except for the new version that i have printed on a tshirt i got at the american fern society. this one’s labelled with both the species name and the common name as well as the full plant, and is waaaaay simpler to understand:
i marked this up a little to explain it better. basically its a rough sketch of the relationships between all the ‘species’ that form the complex. wagner notes also that there are some that should exist that haven’t been spotted in the wild, and some that may only ever be able to be replicated in laboratory conditions.
since this paper, this method of mapping the groups of ‘species’ that straddle the line like this to form complexes has been widely used not only in fern studies (ferns fuck a LOT like….SO much) but also throughout the plant and animal kingdoms to show how things happen when a few separate ‘species’ don’t stop at The Fuck Line and start breeding together. yes, i said animals. one of the most prominent complexes noted in not-plants is the infamous tiger salamander complex, which confused scientists when the ‘species’ they had named throughout mexico….seemed to kinda blend together??? spoiler alert: they ended up not only fucking among each other and making weird hybrid salamanders, but also doing some other wild genetic shit seen virtually nowhere else in the animal kingdom, which involves a process where a female and and a male (same species not required) Fuck, but instead of fertilizing the egg with the sperm, you know, like a normal organism, the female either gets rid of the sperm and makes clones of herself, tentatively adds some of the sperm genome to the offspring’s genome, or gets rid of her egg’s genome and makes the eggs weird fucked up semi-hybrids with traits most closely related to the male.
so anyway back to the original question as to what makes a species: everyone has different opinions, and those opinions give way into some new ways of describing species that really straddle the line in how they define themselves. for some reason, carnivorous plants- especially nepenthes and american pitcher plants- are really, really good at forming complexes, and they just….Fuck, man. they just fuck a whole lot. they just dont care
update: i’ve learned from the tags and notes on this post that the different ways that we can define species are called ‘species concepts’. the one that’s most widely taught in high schools is called the Biological species concept, which states that if two species Can’t Fuck, then they’re different species…but apparently this is one of between 26 and 30 different main definitions of what a species is, and they’re applied differently to different situations.
a few other definitions include:
morphological species concept: if they’re different and look very different, then they’re different species
differential fitness species concept: if one has something that it would be hard for the other one to have, then they’re different species (a dog and a fish are different species because it would be hard for a dog to have gills)
compilospecies concept: a kind of species that is so good at Fucking that it can Fuck other species to extinction, as in, it interbreeds so much with it’s related species/other species in it’s complex (if it’s identified as a complex, that is) that eventually, the other species are absorbed into it’s own species. if we apply this to the triangle, it would be like if one of those hybrids/species fucked so much that the triangle became obsolete, because all the species became so genetically similar to The Super Fucker overtime that we can just refer to them as one species now.
nothospecies concept: coined by Wagner in 1983 to explain a way we can consider looking at hybrid species, which says that a species formed by two closely related species Fucking is a species of its own. so in a wolf/dog hybrid, the wolf, dog, and wolfdog and all technically different ‘species’ under this idea.
there are waaayyyy more than this obviously but yeah apparently ‘species’ are best referred to on a case by case basis. some are totally rejected by everyone, some are used a lot but can’t be used in some special cases, some are best used in certain situations……..its all a big mess
note: the concept of a ‘complex’ isn’t a species concept of it’s own, but rather is sometimes applied functionally to describe the relationship between Species That Are Fucking. so the ferns are still in a state where they’re Always Fucking, and we recognize that gene flow between them, but how we go about assigning what we call The Fuckers from there is where species concepts come in (asking questions like ‘which one of these is a species, exactly??’).
ForLoveFromFear 