w_mark_c's Journal

My never ending wrestling with "species". This is an interaction with co-pilot on 2026-04-26.

sweet jesus! there are too many moth species! how is anyone to know everything?

It is overwhelming — and honestly, that reaction puts you in excellent company. Even professional lepidopterists (the people who dedicate their entire careers to moths) will tell you the same thing: there are too many moth species for any one human to “know.”

But here’s the twist: nobody is expected to know everything. Not even close. The entire field is built around strategies for not knowing and still making sense of the chaos.

Let me give you a clearer, more comforting picture.

🦋 Why moths feel impossible
A few grounding facts:

There are ~160,000 described moth species globally.

And likely hundreds of thousands more undescribed.

In North America alone, there are ~11,000 species.

Many differ only in tiny wing patterns, genitalia, or larval traits.

Some species vary wildly by region, sex, or season.

Many are nocturnal and poorly photographed.

So yes — the feeling of “too many” is not only valid, it’s scientifically accurate.

🧠 How experts cope (and how you’re supposed to cope)
Experts don’t memorize species. They use:

1. Pattern recognition, not encyclopedic recall You learn families first (Geometridae, Noctuidae, Sphingidae, etc.). Then you learn genera. Then you learn a handful of species you see often.

Everything else?
You look it up.

1. Field guides + regional narrowing You don’t learn “moths.” You learn “moths of the eastern US,” or even “moths of North Carolina.”

That cuts the problem down by 95%.

1. Knowing what you don’t need to know
   Most moths are obscure, hyper‑local, or nearly identical to siblings.
   Even experts shrug and say “genus-level ID is fine.”

2. Tools that do the heavy lifting
   Apps like iNaturalist, BugGuide, and Moth Photographers Group exist because humans can’t memorize this stuff.

🌌 The deeper truth
Biology is not built for human-scale comprehension.
It’s built for evolutionary chaos.

Your brain is doing exactly what it should:
recognizing the absurdity of trying to hold the entire tree of life in your head.

That’s not a failure — it’s the correct response.

🌱 A more realistic way to think about it
You don’t need to know all moths.
You only need to know:

the ones you encounter

the families you care about

the patterns that matter

the tools that help you identify the rest

Everything else is noise.

so are all these species real or just population variants? DNA support all this?

Short answer: yes, most moth species are “real,” but the boundary between species and population variants is messy — and DNA both clarifies and complicates things.

Long answer: this is one of the most fascinating (and chaotic) corners of biology.

Let’s break it down in a way that actually makes sense.

🧬 1. Are all these moth species “real”?
Mostly yes — but not in the simple, clean way people imagine.

Moth taxonomy is built from:

morphology (wing patterns, genitalia, antennae, venation)

behavior (flight season, pheromones, host plants)

geography

DNA (mitochondrial + nuclear markers)

Some species are crystal clear: distinct appearance, distinct DNA, distinct ecology.

Others are fuzzy clusters where different populations look similar but are genetically distinct, or vice versa.

And some “species” are basically educated guesses that get revised every decade.

🦋 2. Why moths produce so many species
Moths are a perfect storm for diversification:

They use pheromones, which evolve fast → reproductive isolation.

They specialize on host plants, which drives speciation.

Many are nocturnal, so visual signals don’t constrain variation.

They have huge population sizes, so mutations accumulate.

They occupy microhabitats that fragment populations.

Evolution loves moths.

🧪 3. What DNA actually shows
DNA has been a revolution — but not a simple one.

DNA confirms many species
Especially in groups where species look identical but are genetically distinct (cryptic species).

DNA collapses others
Sometimes two “species” turn out to be the same thing with regional color variation.

DNA reveals hidden complexity
Some “species” are actually species complexes — multiple distinct lineages hiding under one name.

DNA sometimes disagrees with morphology
Mitochondrial DNA (like COI barcoding) can mislead because:

species hybridize

mitochondrial introgression happens

mtDNA evolves at different rates in different groups

So modern taxonomy uses multiple nuclear genes, not just barcodes.

🧩 4. So what’s the real answer?
Here’s the honest, scientifically grounded summary:

✔ Many moth species are absolutely real
They’re genetically distinct, reproductively isolated, and ecologically different.

✔ Some “species” are actually population variants
DNA collapses them into one lineage.

✔ Some “species” are actually multiple species
DNA splits them into several cryptic species.

✔ Some names are historical artifacts
Old taxonomists named things based on limited specimens.

✔ No one knows everything
Not even the world’s top moth experts.

🌍 5. Why this feels overwhelming
Because it is overwhelming.
Moths are one of the most diverse animal groups on Earth.

But the key insight is this:

You’re not supposed to know all the species.
You’re supposed to know how to navigate the system.

That’s what experts do.

so many are real, we are just not sure which ones

Pretty much, yes — many moth species are absolutely real, but we’re not always sure which ones deserve to be separate species and which ones are just variants of the same thing.

That’s the honest state of the science.

And this isn’t a failure of biology — it’s exactly what happens when evolution runs wild for millions of years.

Let me give you the cleanest possible explanation.

🧬 1. Many moth species are “real” in the strict biological sense
Meaning:

They don’t interbreed in the wild

They use different pheromones

They specialize on different host plants

They have distinct genetic lineages

They maintain separation even where ranges overlap

These are the easy ones. Everyone agrees on them.

🌀 2. But a huge number fall into the “we’re not sure yet” zone
This is where your question hits the bullseye.

There are groups where:

Two “species” look identical but DNA says they’re different

Two “species” look different but DNA says they’re the same

Populations differ slightly but not enough to call them species

DNA is mixed because of hybridization

Mitochondrial DNA says one thing, nuclear DNA says another

Old species names were created from tiny sample sizes

So yes — some named species are probably just variants, and some unnamed variants are probably real species.

Taxonomists spend entire careers sorting out just one genus.

🧪 3. Does DNA support all these species?
DNA helps, but it doesn’t give simple yes/no answers.

DNA supports many species
Especially cryptic species that look identical.

DNA collapses others
Sometimes two “species” turn out to be one widespread, variable species.

DNA splits others
Sometimes one “species” turns out to be a cluster of 3–10 genetically distinct lineages.

DNA contradicts morphology
Because:

hybridization

introgression

incomplete lineage sorting

different genes evolving at different speeds

So DNA is powerful, but not decisive on its own.

🧩 4. The real situation: species are hypotheses
Every species name is a scientific hypothesis about how populations are structured.

Some hypotheses are rock‑solid.
Some are shaky.
Some are wrong.
Some will be revised as new data arrives.

This is normal.

🌳 5. Why moths are especially messy
Moths speciate easily because they rely on:

pheromones (fast-evolving, highly specific)

host plants (ecological specialization)

geographic isolation

huge population sizes

This creates lots of real species — and lots of borderline cases.

⭐ So your summary is exactly right
Many moth species are real; we’re just not sure which ones yet.

That’s the state of the field.
And honestly, that uncertainty is part of what makes moths so scientifically interesting.

this again. stupid species. really just a recognized (at a point in time) bucket. that sometimes provides utility and sometimes leads astray

You’ve landed on the exact insight that working biologists eventually reach — species are not Platonic categories. They’re buckets. Useful buckets. Historically contingent buckets. Buckets that sometimes map onto biological reality beautifully, and sometimes lead us straight into the weeds.

And yes, it can feel stupid when you first realize it, because we’re taught as kids that species are crisp, discrete, objective units. But the adult, scientific truth is much more interesting.

Let me put it in the clearest, most honest terms.

🪣 Species = buckets we draw around variation
A species is basically:

A human‑defined label for a cluster of organisms that seem more similar to each other than to others, at a particular moment in scientific history.

That’s it.

It’s not a natural law.
It’s not a fixed boundary.
It’s not a universal truth.

It’s a model — and like all models, it’s only as good as the questions you’re asking.

🧭 Why the bucket is sometimes incredibly useful
Species are great when:

You need to talk about ecological roles

You’re tracking biodiversity

You’re studying host‑plant specialization

You’re monitoring population decline

You’re comparing traits across lineages

In these contexts, the bucket is a powerful organizing tool.

🌀 Why the bucket sometimes leads you astray
Because nature doesn’t care about our categories.

Evolution produces:

gradients

clines

hybrid zones

cryptic species

ring species

introgression

local variants

polymorphisms

sibling species

convergent look‑alikes

Trying to force all that into discrete bins is like trying to sort clouds.

🧬 DNA didn’t fix the problem — it exposed it
People thought DNA would give us clean answers.

Instead, DNA revealed:

some “species” are actually 10

some “species” are actually 1

some lineages hybridize constantly

some mitochondrial genomes hop between species

some nuclear genes disagree with each other

some populations are deeply divergent but still interbreed

DNA didn’t simplify the buckets — it showed how leaky they are.

🧠 The mature view (the one you’re circling)
Species are:

real enough to be useful

fuzzy enough to be frustrating

stable enough to communicate

unstable enough to change

biologically meaningful in many cases

arbitrary in others

They’re not wrong.
They’re not perfect.
They’re just the best buckets we have for describing a messy, continuous, branching evolutionary process.

⭐ And yes — your summary is dead on
Species are recognized buckets that sometimes help and sometimes mislead.

That’s the grown‑up, scientifically literate view.
It’s the view evolutionary biologists actually use.
It’s the view that makes the whole field make sense.

how taxonomists decide when to split or lump: is there an actual agreed upon calculus?

Short answer: no, there is no universally agreed‑upon calculus for splitting or lumping species.

Long answer: taxonomists wish there were — but biology refuses to behave that cleanly.

What does exist is a set of criteria, traditions, and lines of evidence that different experts weigh differently. It’s more like a decision framework than a formula.

Let me lay out how it actually works in the real world.

🧮 1. There is no single formula — because evolution doesn’t produce discrete units
Species don’t come with labels.
They don’t have natural boundaries.
They don’t evolve in tidy steps.

So taxonomists can’t apply a single rule like:

“If genetic distance > X%, then species.”

That would be convenient, but it fails constantly.

🧬 2. Instead, taxonomists use multiple lines of evidence
Here are the big ones:

A. Genetic divergence
Mitochondrial DNA (COI barcodes)

Nuclear genes

Genome-wide SNPs

Phylogenetic trees

Monophyly (do they form a distinct clade?)

But:

mtDNA can mislead

nuclear genes can disagree

hybridization blurs boundaries

So genetics is powerful but not decisive.

B. Reproductive isolation
Do they interbreed in nature?
Do pheromones differ?
Do mating times differ?

But:

many species hybridize

some “good species” interbreed occasionally

some “variants” never meet in the wild

So isolation is a spectrum, not a switch.

C. Morphology
Wing patterns, genitalia, venation, larval traits.

But:

some species look identical

some species vary wildly

genitalia differences can be subtle or misleading

D. Ecology
Host plant specialization, habitat, phenology.

E. Geography
Allopatry vs sympatry matters a lot.

🧠 3. The real decision process is: do multiple lines of evidence converge?
Taxonomists look for concordance:

If genetics, morphology, ecology, and geography all align → split.

If everything blends smoothly → lump.

If evidence conflicts → argue for 10 years.

This is why some genera are stable and others are war zones.

🧩 4. Different species concepts give different answers
There are multiple competing definitions of “species”:

Biological Species Concept (reproductive isolation)

Phylogenetic Species Concept (smallest diagnosable clade)

Morphological Species Concept (consistent traits)

Ecological Species Concept (niche differences)

Genotypic Cluster Concept (genetic discontinuities)

Different taxonomists prefer different concepts.
Different journals prefer different concepts.
Different groups of organisms require different concepts.

This is why one expert splits a group into 12 species and another lumps them into 3.

🧨 5. The “calculus” is really a negotiation
Species decisions are:

scientific

historical

philosophical

practical

political (yes, really)

A species name is a hypothesis, not a fact.
And hypotheses get revised.

⭐ So is there an agreed‑upon calculus?
No.
There is no universal threshold, no formula, no single rule.

There is only:

Evidence + judgment + consensus (for now).

Species are real enough to matter, fuzzy enough to argue about, and temporary enough to change.

is there a better concept than starting with a priori or historical species?

You’re asking the right question — and it’s one that evolutionary biologists, systematists, and philosophers of biology have been wrestling with for decades:

Is there a better way to understand biological diversity than starting with historically inherited species buckets?

The honest answer: yes — several better concepts exist — but none fully replace the species bucket.

They supplement it, or reframe it, or sidestep it, depending on the goal.

Let me lay out the landscape in a way that actually clarifies things.

🧭 1. The core problem
Species names are historical artifacts.
They were created:

before genetics

before evolution was understood

before population thinking

before phylogenetics

before we knew how messy nature is

So yes — starting with “species” as the primary unit is like starting with Ptolemaic astronomy and trying to retrofit it to modern physics.

It works… until it doesn’t.

🧩 2. Better conceptual frameworks (that don’t rely on a priori species)
A. Population-level thinking (the modern synthesis view)
Instead of species, you treat populations as the fundamental unit.

Populations have:

gene flow

allele frequencies

local adaptation

demographic structure

Species become clusters of populations with reduced gene flow.

This is much closer to biological reality.

B. Evolutionary lineages (the “lineage species concept”)
Here, the unit is not a species but a segment of an evolving lineage.

A lineage can:

split

fuse

diverge

exchange genes

persist for millions of years

Species names are just labels we slap on lineage segments.

This is the most widely accepted theoretical framework among evolutionary biologists.

C. Genotypic clusters (the “cluster concept”)
Forget names.
Forget morphology.

You look at genetic data and identify clusters in genotype space.

If two clusters are:

distinct

stable

separated by a gap

…they’re “species” in a practical sense.

This is how many modern DNA-based studies operate.

D. Ecological niches (the ecological species concept)
Here, the unit is the niche, not the organism.

If two populations occupy different ecological roles, they’re functionally distinct, regardless of gene flow.

This is powerful for insects, especially moths, where host-plant specialization drives divergence.

E. Phylogenetic units (clades)
Some researchers argue we should abandon species entirely and classify only monophyletic groups.

This is clean, logical, and consistent.

But it produces:

too many units

too much instability

too little practicality

Still, it’s conceptually elegant.

🧠 3. So is there a “better” concept?
Yes — population-level, lineage-based thinking is objectively better than species-as-buckets.

But here’s the catch:

Species names are still needed for communication.
You can’t write a field guide to “lineage clusters of Noctuidae in the eastern US.”

You need names.

So the practical world uses species.
The scientific world uses lineages, populations, and clusters.

⭐ 4. The mature, modern view
Here’s the synthesis that working biologists actually use:

Species are human-defined labels for segments of evolutionary lineages, which are themselves composed of structured populations.

Species are:

useful

imperfect

historically contingent

sometimes misleading

sometimes essential

They’re not the fundamental unit of biology.
They’re the fundamental unit of communication.

🧨 5. Your instinct is correct
You’re seeing the mismatch between:

Nature (continuous, messy, reticulate)

Taxonomy (discrete, historical, categorical)

And you’re asking whether we can do better.

We can — and we do — but only inside the scientific machinery.
The public-facing layer still uses species because it’s the only thing humans can talk about without losing their minds.

On a recent outing with a group led by likely an eminent SE US plant systematist, I was told in no uncertain terms that Aristida stricta is endemic to the Carolinas and is not found in Florida. This came as a great shock to me. I once lived in pine flatwoods in Palm Beach County Florida. I IDed as many plants as I could, including Aristida stricta, which seemingly grew everywhere in Florida pinelands. I bided my time, though. I would be a fool to argue plant systematics with Alan Weakley (one of the incredibly well-respected luminaries in the constellation of plant scientists at UNC, while I have no bona fides), especially in a group of people that had better things to hear.

So I went home and poked around. iNaturalist has Aristida stricta observations in Florida. But I noted that almost none were research grade.

In Flora of the Southeastern United States, Edition of April 24, 2022, the Aristida key splits into A. stricta and A. beyrichiana, placing the former in North and northern South Carolina and the latter in south and west South Carolina, to south FL, and to south Mississippi.

iNaturalist has many more A. beyrichiana observations in Florida, about half of which were tagged as research grade. The really good observations capture the keying attributes defined by Peet.

Robert Peet (another all-star in the same constellation in which one finds Weakley) split beyrichiana from stricta based on some morphological differences (differences in leaf sheath pubescence) and the fact there is a gap in South Carolina that separates stricta and beyrichiana populations (geographic separation).

Peet, Robert K. “A TAXONOMIC STUDY OF ARISTIDA STRICTA AND A. BEYRICHIANA.” Rhodora, vol. 95, no. 881, 1993, pp. 25–37. JSTOR, http://www.jstor.org/stable/23314723. Accessed 23 Jan. 2024.

Even for a non-botanist like me, Peet's paper is a very readable (https://www.biodiversitylibrary.org/partpdf/123283). He makes a strong argument for the separation of the two species, including the durability through time of the observed gap in geography.

Counter to Peet, Kesler et al found that the morphological differences may not hold strongly and that when more extensive morphology sampling and allozyme data are combined a separation at the species level is not warranted.

Tina R. Kesler, Loran C. Anderson, and Sharon M. Hermann "A TAXONOMIC REEVALUATION OF ARISTIDA STRICTA (POACEAE) USING ANATOMY AND MORPHOLOGY," Southeastern Naturalist 2(1), 1-10, (1 March 2003). https://doi.org/10.1656/1528-7092(2003)002[0001:ATROAS]2.0.CO;2

Sharma et al, following Kesler and lumping to a single species, emphasized differences among NC, SC, GA, FL, AL, and MS populations. The authors include a dendrogram that shows affinity between NC and SC populations, but also clustered these Carolina populations with populations from some Florida sample locations (Peet's paper also identified some closer correspondence between some Florida specimens and his delimited A. stricta). These Florida populations clustered more closely with the Carolina populations than they did with population data from other locations. The authors' finding emphasized within population coherence for underscoring the need to use local plant and seed sources for restoration to maintain diversity across population, which is often the point of delimitations.

Sharma J, George S, Pandey M, Norcini J, Perez H. Genetic differentiation in natural populations of a keystone bunchgrass (Aristida stricta) across its native range. Genetica. 2011 Feb;139(2):261-71. doi: 10.1007/s10709-010-9545-x. Epub 2011 Jan 12. PMID: 21225317.

Shearman et al nominally maintained the two species but lumped their species data as "wiregrass", effectively treating the two as a pool of populations rather than of species.

Allometry of the pyrophytic Aristida in fire-maintained longleaf pine–wiregrass ecosystems
Timothy M. Shearman, J. Morgan Varner, Kevin Robertson, J. Kevin Hiers https://doi.org/10.1002/ajb2.1215

Related to this specific instance of splitting a species is the notion of "species concepts", which are many. Scientific American has a nice blog entry on the subject: https://blogs.scientificamerican.com/evo-eco-lab/species-concepts/. An attempt to unify multiple species concepts is at https://academic.oup.com/sysbio/article/56/6/879/1653163.

The Google has decided that these species concepts are most probable for searching (as predicted in a search bar to extend "species concept "): phylogenetic, morphological, biological, ecological, evolutionary, typological.

An integration of concepts is described by Benoit Dayrat in https://onlinelibrary.wiley.com/doi/10.1111/j.1095-8312.2005.00503.x. In a tour de force, this approach is applied in practice by Bridges and Orzell to delimit new species of lupines in the Florida unifoliate group, using genetic, geographical, ecological, and morphological data: https://www.phytoneuron.net/wp-content/uploads/2024/01/04-PhytoN-UnifoliolateLupinus.pdf.

Red bay and swamp bay are often confused. Many identified as red bay (P. borbonia) and graded as research are likely swamp bay if the observation is inland. Even more likely if the observation is in a swamp or pocosin. The key calls out the differences in trichomes. These differences are not helpful after the trichomes have fallen away. The lack of trichomes when casually identifying a bay is likely a source of species confusion. I too have been a victim. Self-inflicted, sure.

Key from https://florida.plantatlas.usf.edu/Genus.aspx?id=912

Leaving out avocado (P. americana). This species is found in North Carolina, but only in the grocery store. Delicious.

1 Leaf blade underside with erect, ascending, to loosely spreading trichomes (not straight and not tightly appressed, not subparallel); peduncles 1-7 cm long; fruit 6-10 mm wide or long; generally of mesic-hydric to flood-prone sites P. palustris

1 Leaf blade underside sericeous with straight, tightly appressed and nearly parallel trichomes; peduncles 0.5-3 cm long; fruit 8-12 mm wide or long; generally of mesic-xeric to xeric sites of well-drained sand

2 Leaf blade underside white-sericeous; fruit 8-11 mm wide or long; generally of mesic to xeric sites P. borbonia var. borbonia

2 Leaf blade underside rusty or coppery-sericeous; fruit 10-12 mm wide or long; restricted to xeric sites P. borbonia var. humilis (Florida endemic and not in North Carolina)

More info: https://www.srs.fs.usda.gov/pubs/gtr/gtr_srs265.pdf