I guess it all boils down to how you count species? What even is a “Species”?
Is it more rewarding/easier to create new species instead of discovering them? why not both!
Why do Hybrid species get an × infront of their name like with Typha × glauca or Phaseolus × dumosus? But Brassica napus doesn’t despite being a clear hybrid between Brassica oleracea x Brassica rapa doesn’t?
Same question extends to new plant genus we invented × Brassicoraphanus, which is a hybrid between Radish (Raphanus spp.) & Cabbage (Brassica spp.).
What about × Amelasorbus which is an intergeneric hybrid between Amelanchier x Sorbus?
Yet why did Zea mays become a new species when we domesticated it? Same extends to Solanum lycopersicum, Cucumis melo & Cucurbita moschata which apparently has no “wild” relatives? If so, can this process be repeated with any other wild plant? How many crosses do you have to make until you have what’s considered a new species? Is a Landrace Hybrid Swarm of many diverse varieties a Speciation event in your garden?
Not all taxonomists agree on this, but domesticated forms are often given a scientific name separate from their wild ancestral form. The horses Equus caballus (domestic) and Equus ferus (wild) is an example. If nothing else, it helps us define which is which if both are still extant. I can’t speak to plants where there might be a complicated history involving both domestication and hybridization.
The usual distinction (not always consistently applied) is between:
something of hybrid origin at some time in its past, but which is now an independently reproducing lineage on its own evolutionary trajectory - general considered a species (since this is now known to have been a common speciation mechanism, especially in plants), versus
recent products of hybridization which have not (yet) formed their own independently reproducing lineage (for reasons like sterility, lower fitness relative to their parents, complete interfertility with one or both parents, etc.) - generally given a hybrid designation (if named at all) to differentiate them from independent species (even though the latter may have originated as hybrids).
This distinction can be hard to assess with crops under constant cultivation and selection, because we usually don’t know how they would behave if left on their own.
If my landrace started out as a Hybrid Swarm of many different species that all throughly introgressed & combined into 1 uniform but diverse population, it’s a new species right?
My Landrace Plant Breeding goal is to cross all 5 domesticated Cucurbita species (C. pepo x C. moschata x C. angyrosperma x C. maxima x C. ficifolia) into 1 very thoroughly introgressed population via constant gene flow until the distinct species lines blur into each other, leaving the entire population as a whole new species (Or would it still be a species complex?).
I’m taking notes from when Cucurbita pepo used to be 2 species, it was created when Cucurbita texana & Cucubita fraterna hybridized & retrogressed so much that they merged into 1 species, leaving evidence as Subspecies inside Cucurbita pepo. This would explain why Cucurbita pepo is just a Polymorphic species, if it’s made up of 2 ancient species.
Same exact situation happen with Cucumis melo which was created 2-6 ancient species (Or Sub-species now) crossed into each other. You can still see somewhat relatively distinguish 2 subspecies in Cucumis melo. It would explain why it’s so Polymorphic, if it’s made up of 2-6 species (Depending on whose counting), all together form a species complex.
The only inconsistency I noticed is with the Amaranthus hybridus complex, why are A.caudatus, A. hypochondriacus and A. hybridus all considered separate species if they have already fully introgressed into each other throughly enough to make Plant ID pointless. It should’ve had the Cucumis melo or Cucurbita pepo treatment done to it already, why the taxonomic delay?
Bringing back to my point, I can repeat these introgression events with all sorts of species, why stop at my 5 species Squash Landrace?
Or when I fully introgress Cucumis metuliferus x Cucumis melo into a uniform Landrace where the lines between species blurred beyond distinction.
Of course this landrace will branch off into it’s own evolutionary pathway due to my selection pressures like Yield, Taste, Flavor, Ease of Harvest, Adaptibility, ect.
To me, the answer would depend on what that population was doing (if anything), on its own, many generations after you and I are gone. It would be up to botanists / taxonomists of the future to decide whether your hybrid creation ended up being the origin of a new species or not.
This has been discussed many times on this forum, but it is worth repeating: A species is any group of organisms that a taxonomist considered knowledgeable in that taxon decides is a species, and publishes as such, using whatever definition or criterion that taxonomist prefers at the moment the analysis is performed. In cases where taxonomists disagree on species boundaries, it becomes a popularity contest.
hmm… I see. Makes me wonder how many “Species” are lost & forgot ancient hybridization events facilitated by our Human Ancestors? I feel such a wide hybridization event would still have an impact, but the question still remains how much of an impact.
I’m thinking about Pawpaw (Asimina triloba), how did the fruits get so big? Surely Native Americans selected for the biggest, best tasting fruits which may explain why Pawpaw is so widespread & has so much variation. Being a perennial species adds a layer of protection Eastern Agricultural Complex Annual crops didn’t have to preserve their genomes. Perhaps what we find in the wild are actually semi-wild populations?
I just wonder if there are any animal species that maintain selection pressure on certain plant species, since it all counts under the term of “Natural Selection”?
I just think back to Bears eating only the tastiest Blackberries is a Selection Pressure for best tasting berries, if the bears were no longer doing that job, would the Blackberries revert back to what exactly?
If we replace bear with a Human in the example, same thing applies? Is it still natural selection? Or as soon as the Homo-sapien species is involved, automatically no longer natural selection by definition cuz human selection is always branded as “artifical selection”.
Interesting, so in other words Scientific Names have the same Human problem that Common Names have?
As I understand it, a Taxon = life thing. This could be a species, genus, family, order, variety, subspecies, subgenus, ect because all of these names are ranks of a life thing.
That depends on the effects created by such consumption. If the effect were to prevent those fruits from propagating new plants, it could actually select against berries tastier to bears.
Selection is selection, regardless of its source. Because selection is often a fraught term, I prefer to use the somewhat wordier phrase, “differential survival of heritable traits.”
Names and ranks are not the same things as the underlying real biological entities to which we apply those names and ranks. The challenge is not that “species are artificial human concepts” as many will claim, but rather to apply the rank of species in biologically consistent way(s) given the wide diversity of real biological entities in nature, and our limited abilities to understand and characterize them.
The original question was about long-ago hybridization, but we should also note that some domesticated species are different from their wild ancestors even withough hybridization. Would anyone here argue that Felis catus should be synonymous with Felis sylvestris? Should we synonymize the two domestic cattle species, Bos taurus and Bos indicus, with the extinct wild ancestor Bos primigenius? For that matter, Bombyx mori is considered different from Bombyx mandarina.
Domestic dogs (Canis familiaris) clearly evolved from wolves (Canis lupus), with many, many morphological, physiological, and genetic changes. There seem to be good reasons for considering these different species, even though dogs of the appropriate size can interbreed with wolves to produce fertile offspring.
Well the idea being the bear poops out blackberry seeds from the ones he ate most of. Interesting, is this why all my local Blackberries around my neighborhood taste like shit? My area has too much deer, Since deer mostly just eat the greens, Blackberries have to become super thorny to survive, they don’t seem to go after the berries as I saw berries fully dried left on the old canes from last year.
I see… does this explains why some species ranks don’t weigh the same, containing more diversity inside a species taxon compared to others.
I look at super highly diverse Cucumis melo which is actually a species complex of many wild subspecies that created it but then I look at Rubus allegheniensis, Rubus pensilvanicus & Rubus argutus which barley have any differences.
Clearly 1 taxon weighs more than 3 taxons of a different plant family, that 1 Cucumis melo taxon contains more diversity inside it than 3 Rubus taxons combined, why the discrepancy?
I see the same unequally weighed species concept play it in so many plant families. The way we circumcise taxons is very unequal to the genetic reality each taxon box represents. Nature doesn’t fit into neat equally weighed taxons.
I don’t know nothing about animals, but with plants are you saying micro-adaptation thru asexual adaptations (Often thru a Genetic Mutation event)?
I’ve heard people say the same garlic they’ve been planting became different after growing in different soil conditions, almost like there was some Horizontal Gene Flow between the soil-life organisms & the Garlic Plant (Despite Garlic Forgetting how to Make Flowers for Sexual Reproduction).
Perhaps if this is what you mean? idk… But nearly all the plants we have were created by seeds thru sexual reproduction thus all are hybrids making seeds after their own kind (Hybrids within a species, hybrids across species & even Hybrids across Genera).
Yes, absolutely, Scientific Names have many of the same problems that common names have. Not all of them though. To bring it back to hybrids, anyone can hybridize two varieties of a plant and give it a new common name. To give it a new scientific name, they are supposed to go through publication and peer review, which in theory involves people who know about hybridizing those plants, which means they could say, “Hey, wait, the hybrid of that species and this species already has an accepted scientific name, so we don’t accept this new one.” So synonyms are often found and hopefully eliminated. But then someone could come along and say, “well actually that hybridization was described and named by the venerable so-and-so in 1826 and therefore the name everyone has been using is the junior synonym and has to be eliminated.” And then someone else can come along and say, “well, actually both parent species of that hybrid are actually different varieties of a single species, so it isn’t really a hybrid at all, just an introgression, and therefore doesn’t get a name at all!” This kind of thing goes on all the time, often changing back and forth repeatedly over decades, and makes scientific names not nearly as stable as many people believe.
A taxon is a group of related organisms, preferably all of which are more closely related to each other than they are to anything else. This is called being monophyletic. But members of a hybrid species are often not monophyletic, meaning some of them may be more closely related to members of the parent species than to other hybrids in the new species.
I very much disagree, and know many evolutionary biologists who do also. The problem isn’t that all organisms are divided into some objective groups called species that are challenging to discern. The problem is that we find it very useful to categorize things that don’t necessarily fit into any sharply delimited categories, and therefore struggle to shoehorn them into boxes of our own making. For nearly a century the literature in evolutionary biology has been full of angrily debated new species concepts, and most evolutionary biologists now agree that there is no definition of a species that means what we want it to for most living things. Species are a linguistic convenience which the taxonomists in each group try to line up with what feels to them like useful groupings.
Not necessarily. For example, pigeon fanciers have developed very diverse breeds of pigeons just by selecting for pigeon mutations that interested them. The tremendous diversity of dogs has been produced mainly by selection for variations within the dog species (although wolves continue to contribute a small amount to some dog lineages in some areas).
Just an issue of technical terminology: We biologists usually use the word “hybrid” to refer to individuals produced by the breeding together of members of two different taxa. We generally don’t use “hybrid” to refer to individuals produced by sexual reproduction within a species. (When we call something a hybrid, usually the parents belong to two species in the same genus or or species in different genera, but sometimes we use “hybrid” to describe the offspring produced by the crossing of two different subspecies. People breeding plants for the garden will sometimes use “hybrid” more informally to refer to the offspring of two different breeds or cultivars within the same species.)
And what would be the purpose of this? Because you can?
If you are primarily coming to this thread as a plant breeder, why does it matter whether the cultivars you develop are (from a biological standpoint) new species, hybrids, or variants of an existing species? Whether they are successful will depend entirely on whether they have traits felt to be desirable by gardeners and farmers, not whether they are new species or not.
ah I see, it goes through a system! Will the New species have an x in front or no? Or it just depends on wide the hybridization swarm was?
I’m just wondering if all my wide hybridization experiments is going to give a lot of Headaces to taxonomist .
Ah now that makes sense, I’ve seen lots of Phylogenic Trees and I always keep thinking Monophyletic so far… but not until I cross different genera together.
Things get complicated with Rosaceae & Brassicaceae and other plant families that do intergeneric hybrids. Like Raphnaus x Brassica, do we even know what a Brassica is if the whole Brassiceae tribe has potential to cross?
Also if Cucumis melo forms a Monophyletic Clade & Cucumis metuliferus forms it’s own Monophyletic claude & I cross both species together, does that mean it’s no longer Monophyletic & now Polyphyletic? Documented Hybrids between Cucumis metuliferus x Cucumis melo have already been made.
This makes so much sense! Life is constantly evolving so of course they won’t neatly fit into taxon boxes. How do species complexes work? Is taxonomy just slow to relize it’s all 1 species that’s constantly introgressing with subspecies or is every species within a species complex truly separate species?
For example, the Solanum nigrum species complex? Are there Black Nightshades outside the species complex or no? Same Question extends to Amaranthus hybridus complex.
And why isn’t Vigna unguiculata a species complex as well? Or have they properly been fitted into subspecies that Solanum Nigrum & Amaranthus hybridus hasn’t yet?
I see… As long as they are seprate taxons, it’s considered a “hybrid”. Does this include hybrids between Varieties or only subspecies? or does the term hybrid stop being used aftet the species taxonmic rank?
Well. they would be classifed as differnt levels of hybridization no?
Like Interspecific hybridization vs Intraspecific hybridiation? Or what about Intergeneric Hybridization?
Partly yes but also I need to Improve Cucurbita ficiolia with Cucurbita maxima or Cucurbita pepo genetics.
I really enjoy the flavor of Acorn Squash (Cucurbita pepo) and the flavor of Buttercup (Cucurbita maxima), crossing them together would bring me closer to making the sweetest squash ever! Crossing within species I fear will not be enough of what it takes to breed the sweetest/best tasting squash in existence (I hope it leads to more people breeding squash too!)
Plus if I also combine the Tree Climbing Trait form Cucurbita ficifolia, I can have Squash Climb Trees, get it to go invasive & help feed more people! well deer sure don’t help but maybe I can breed squash to out climb deer? idk… Lots of Potential!
well… that’s the million dollar question, depending on how introgressed my landrace becomes, it might not even matter no more. At that point will it be a new species or not?
I want to learn how new species are created in hopes I can take notes & replicate the same Domestication/Introgression Event with other crop species, like with Podophyllum spp. for example.
Learning that Cucumis melo is a species complex consitent of many subspecies explains to me why it’s such a polymorhpic species. Using that knowledge, how many other species can be crossed like this to become more polymorhpic? Surely it doesn’t end at Cucumis melo, Zea mays, Brassica oleracea, Cucurbita pepo, Brassica rapa and many more?
Surely I can repeat this Introgression Event with the Wild Edibles I love to eat/forage for & hopefully grow/domesticate too?
Just think I did this with Claytonia virginica, Podophyllum peltatum, Amelanchier spp., Laportea canadensis, Sicyos angulatus, and so much more!
I guess I’m technically now a “Taxonomist” by trying to make sense of this mess. I’m a Forager x Plant Breeder which requires “Taxonomist” & “Botanist” skill assets to correctly ID what I’m crossing & being able to spot hybrids easily when they actually happen.
Plus I’m hoping this either simplifies the taxonomy by crossing everything so that way I don’t have to remember 1000s of species and can just remember 500.
The problem of hybridization leading to new species, called “reticulate evolution” occur in some other groups. The wheatgrasses provide examples. The species are often well marked – that is, clearly distinct from the other species – but a species may have two or three or even five other species in its ancestry. Deciding how to define the genera has been difficult. We used to divide them into genera defined by simple morphological (structural) traits, even though some species were kind of intermediate. Later, some botanists decided that it was better to define genera by the genomes the species had – chromosomes they had inherited from various ancestors. That’s a handy characteristic for identification! (not.) This seems like it should be clear, but people argue about how to sort the genomes. Sigh.
This is really the key point. The variety of process is enormous, so even though we like to imagine everything as a nicely diverging tree with clearly delineated species that reproduce sexually within themselves but not with other species, everything about that imagined order is frequently violated. Hybridization is a form of reticulation (where branches of the tree come back together or swap genes) and happens all the time. Viral transfer of DNA between unrelated hosts, sexual compatibility that depends on environment, species that usually don’t interbreed only because their ranges usually don’t overlap, asexual populations, endosymbiosis, every messy complicating factor you could name happens far more often than most people assume. We want every living thing to fit into a species, and there is no possible single definition of species that can achieve that given the diversity of evolutionary process. And so in each case we pick a definition that is convenient to that case.
As a plant breeder, you can choose to try to figure out what species each plant is, and whether it is a hybrid or not, which is fine and interesting, or you can mostly not worry about the linguistics and instead focus on your phenotypic goals and what genetics are going to achieve them. Just remember, whatever nomenclature you land on, someone will revise it.
I can agree with that statement by inserting one more word:
there is no possible single operational definition of species that can achieve that given the diversity of evolutionary process
In other words, no single measurable criterion (like reproductive incompatibility, for example). Many historical species “concepts” have actually been operational “species criteria” which, of course, are doomed to failure for organisms that don’t self-organize by those criteria.
But if one is willing to entertain attempts at a unified conceptual framework for what kind of biological unit we have “meant” by species, down through the ages and across evolutionary processes and reproductive modes - such as the General Lineage Concept - then it becomes a trivial matter that we have to employ different operational criteria to investigate the population lineages that exist in different groups of organisms, or that independent lineages can originate by both divergent and reticulate processes (and can continue to exist despite the latter).
I agree that if what we want is a definition that isn’t operational, meaning that we can’t actually use it for anything, then coming up with a broad definition is easy. “A species is whatever one feels like it is at that moment.”
Imagine a single bio-engineered organism that isn’t part of any recognizable lineage, but has DNA from hundreds of different organisms as well as some AI generated sequence to patch it all together. Somewhere in the world some lab is attempting this right now. The scientists who eventually succeed, even if it only lives a few days and fails to reproduce, will surely describe it as a new species when they publish. Their name will be accepted specifically because we want every living thing to have a label, and species are those labels.
Can a species be multiple unrelated lineages that we haven’t yet learned to distinguish in the field? Absolutely. Can it be members of a lineage when examined by this taxonomist but not that one? Frequently.
There is literally no firm limit on what we will call a species except that you (usually) have to get a journal editor and a few peer reviewers to go along. So all @professor_porcupine has to do to invent a new species thru domestication is come up with a name and successfully publish it.
Just FYI, there are some folks creating new parthenogenetic hybrid animal species in the lab and naming them (whiptail lizards in the genus Aspidoscelis). These are not bioengineered, just putting two species together that overlap in range and might or might not interbreed in the wild and letting (facilitated) nature take its course.
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