I have read in some posts which use the term “ecotype”, and I was curious as to what it meant. According to Google Search:
ec·o·type
/ˈēkōˌtīp,ˈekōˌtīp/
noun
BOTANY•ZOOLOGY
a distinct form or race of a plant or animal species occupying a particular habitat.
I even searched Wikipedia about this, but I felt unsatisfied with its examples. Could fellow iNaturalists provide better examples of ecotypes using observations on iNaturalist? Also, do you think ecotypes are useful terms? For instance, I have seen that is some places, Peppered Moths in pictures are brown rather than black. Would the brown form be considered an ecotype since I have seen it pockets on the West and East coast? Also, are morphs the exact same thing as ecotypes, or is there a subtle distinction between the two?
Some animals that are adaptively colored for certain substrates — light colored on white gypsum dunes or dark colored on lava fields — can be called ecotypes or ecomorphs but might also be described as subspecies as well. But we seem to be moving away from subspecies in many cases although the ecotype is still useful for recognizing these forms.
The bleached earless lizard on White Sands in NM is, I think, an example of an ecotype. It’s also a subspecies.
Also, you can have color morphs that are not tied to any particular ecosystem. I’m thinking of melanistic forms of Jaguar and leopard that co-occur with typical spotted individuals.
Ecotypes are not-quite-subspecies groupings that appear to be adapted to different ecological conditions.
“Morph” can mean a lot of different things. In my city we have gray squirrels which are either light gray in color or black. One could call these the black and gray morphs (they are usually referred to as color “phases”), and I think it’s genetically determined, but as far as I know, neither one is specially adapted to a certain environment. It’s just a color variation in the species. In certain salamanders, when juvenile density is high and resources are scarce, some individuals will develop into a “cannibal morph” that is specifically able to feed on other normal salamander larvae. If resources remain plentiful, the salamanders will remain normal non-cannibal morphs.
Neither of the above are ecotypes. Ecotypes are distinct forms of a species that have evolved to be adapted to different ecological conditions, but are close enough that they readily interbreed with other ecotypes in their species. I think it would be fair to describe ecotypes as one kind of morph, but not the only kind. I’m sure lots things have been raised and lowered between species, subspecies, and mere ecotype over the course of history.
It gets tricky sometimes. Sometimes what were thought to be ecotypes are later segregated into full species; sometimes the reverse happens. I am thinking of Colocasia esculenta - Colocasia antiquorum - Colocasia aquatilis. Whether these are species or ecotypes depends a great deal on when your source was written and by whom.
The above is pretty close to how I use the term. In my mind an ecotype has some genetic component, but for whatever reason isn’t reproductively isolated from others. This also means that the same ecotype can occur in separate populations that aren’t closely related to each other (relative to others of the same species). That is, members of the same ecotype do not need to be each others’ closest relatives; they could be more closely related to members of some other ecotype.
The later is why ecotypes don’t always get officially named with a taxonomic rank, since today it’s implied that organisms with the same name are most closely related to each other*.
The name “ecotype” dates to 1922 from Göte Turesson, and was important in the work of Jens Clausen in the 1950s, who worked on common yarrow, Achillea millefolium, among other species.
I’ve done some genetic work on Lupinus lepidus, a plant with several varieties across the western US. These varieties weren’t genetically cohesive at all, so I concluded they were ecotypes. The varieties are all officially named, and if you take a look at them on iNat you’ll see that they’re quite different from each other. This is a good demonstration that ecotypes can have very different morphologies, and that recognizing them at some taxonomic level can be a helpful thing, even if it doesn’t exactly fit with their evolutionary history.
I don’t really use the term “morph,” so others might have a better idea, but I see it as representing a phenotype even more ephemeral than an ecotype. This might be something from just a random mutation, like albinism, or a phenotype from just a single population or location.
*This is an ideal I think most current systematists aim for, but definitely isn’t always true in practice.
There’s a lot of slop in how the term is applied but it is as others here have described. Some species show different characteristics in populations that inhabit different environments. Salmoniform fishes include a number of species that display so-called phenotypic plastictity, they look different in different environments. A very interesting and important study on Arctic char of Lake Thingvallavatn in Iceland identified four “incipient species” adapted to different modes of existence, two benthics forms with different feeding specializations reflected in their morphology and two pelagic forms with different feeding specializations reflected in their morphology.
Northern cisco (Coregonus artedi) were once abundant in the Laurentian Great Lakes of North America, and exhibited different forms in different places. They were called lake herring by the first English-speaking Europeans who saw them. A number of other cisco species were described, with the individual lakes exhibiting different combinations of types. Eventually, environmental degradation, fishing pressure, invasive species and (as a range of experts observed) genetic introgression from interbreeding eliminated some types entirely and other types from some lakes until it was believed that there were only lake herring/northern cisco and three other species scattered among the lakes. Then blackfin cisco were found in Lake Nipigon. Then in some small lakes in Algonquin Park. Then, by the organization I work for, in a lake between the Algonquin Park lakes and Lake Huron. Genetic analysis told us that these fish were not really very distant at all from northern cisco.
A study by biologists at Laval University found that the diverse cisco “species” had arisen many times in a bunch of lakes and that in every lake the blackfin cisco, short-jawed cisco, kiyi, bloater, short-nosed cisco and whatnot were most closely related to the northern cisco in their own range, not to supposed conspecifics in other lakes.
These days the tendency is to look at these forms as ecotypes or, more specifically, ecomorphotypes. Here’s a blackfin cisco from near where I live. It’s entered in iNat as a northern cisco.
Modern biology is constructed, in large measure, from ideas developed in the 19th Century to explain the existence of species. The fact of species existence in more or less the Biblical model reflected in the Eden and ark stories was an assumption. The more we dig into it the more it becomes apparent that the species concept is a slippery thing with a lot of examples that don’t fit the assumptions.
This is also one of the reasons why there are such long synonym lists for many species. Individual specimens vary, and in earlier times, when naturalists thought of species as fixed, individual or regional variation seemed enough to name new species or even new genera.
I have even read what I consider convincing evidence that the Labrador duck – which is featured in many books as an extinct species – never was a species at all, but a rare hybrid of two eider species.