Species

Dreamhunter

Ad Honorem
Jun 2012
7,482
Malaysia
* Furthermore … the hybridization has to happen in nature [not planned or caused by humans]. So that if humans find a way to make horses and donkeys have a fertile offspring without generational limitation … horses and donkeys keep on being different species. Even If they are of the same genus [Equus].
Knowing the nature of horses & donkeys, and the nature of animals in general, it would be expected to happen every now & again in nature, even without human manipulation, if the two were living constantly in the same habitat.

Heck. If one has ever lived on a farm, with free range poultry, sheep, goats & all, one wud even be seeing the occasional randy cockerel chasing & mounting a hapless duck, and a rogue drake coupling with an unfortunate hen. No that frequent, but it does happen.
 

AlpinLuke

Forum Staff
Oct 2011
27,057
Italy, Lago Maggiore
Knowing the nature of horses & donkeys, and the nature of animals in general, it would be expected to happen every now & again in nature, even without human manipulation, if the two were living constantly in the same habitat.

Heck. If one has ever lived on a farm, with free range poultry, sheep, goats & all, one wud even be seeing the occasional randy cockerel chasing & mounting a hapless duck, and a rogue drake coupling with an unfortunate hen. No that frequent, but it does happen.
A convention ...

Not occasionally. donkeys and horses, in nature, should normally generate an outspring. In nature this doesn't happen. Horses and donkeys tend not to look for interbreeding and they tend to preserve their reproductive isolation.
 
Dec 2017
308
Regnum Teutonicum
You may find more informed answers on sites where Biologists congregate, than in a room filled with Historians.

I wasn't looking for answers, but more for an interesting discussion. Also I noticed a lot of people in the natural environment subforum having very outdated knowledge, including how they use "species". I thought such a discussion would be useful to some people.


A convention ...

Not occasionally. donkeys and horses, in nature, should normally generate an outspring. In nature this doesn't happen. Horses and donkeys tend not to look for interbreeding and they tend to preserve their reproductive isolation.
… And, if it is (fertile), why should they be defined to be of a different species?


Well, people do consider polar bears and brown bears seperate species, don't they? Even though they produce fertile offspring in the wild.


Was Neanderthal a distinct species, i.e. Homo neanderthalensis, or a sub-species of Homo sapiens, i.e. Homo sapiens neanderthalensis?
They are considered a different species. But a few years ago, it was discovered, that they in fact mixed with modern humans and belong to the forebears of a part of todays humanity.



QUOTE=analysis17456;2916013]How you describe it, they call this process evolution. Of course, it would be a tree instead of just A to B to C and whatever. [/QUOTE]



That is essentially my point - because of evolution the concept of species doesn't exist in reality. But we just continue to use it, because we don't have anything better. The A, B, C and D thing was just a way to break down a more complicated example to give a point. You are right I shouldn't have used it in such a way. But you also shouldn't use such an outdated tree, but an example that follows phylogenetic systematics:).


As usual, we follow conventions, since our mind needs “stable data” to reason. We need definitions to deal with “entities” of any kind and we love to categorize.
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This is exactly the reason why we still (need to) use the species-concept.



* Going backwards through time a species exists until it’s recognizable;
[Equus].


No. A species exists until either it dies out or it splits into two new species (or theoretically possible more than two new species).
 
Jan 2018
1,609
China (Hong Kong SAR)
That is essentially my point - because of evolution the concept of species doesn't exist in reality. But we just continue to use it, because we don't have anything better. The A, B, C and D thing was just a way to break down a more complicated example to give a point. You are right I shouldn't have used it in such a way. But you also shouldn't use such an outdated tree, but an example that follows phylogenetic systematics:).
Alright, if species don't exist, then start your ant-horse hybrid colony, as apparently, the ants and horses are one and the same thing. If you didn't know, I'm also a dolphin.

By the way, it depends on who you're asking, I don't subscribe to the classical definition of species, for example, because I intend to improve it in the future if no one else has to sufficiency. All biologists know that classical biology is severely limited. But I don't understand how you can draw such an insane extension to the assumption that species, therefore, do not exist, doesn't make any sense.
 

Dreamhunter

Ad Honorem
Jun 2012
7,482
Malaysia
They are considered a different species. But a few years ago, it was discovered, that they in fact mixed with modern humans and belong to the forebears of a part of todays humanity.
Well, since they did interbreed with the more mainstream Homo sapiens, and indeed helped co-produce some fertile & viable hybrid Homo-neanderthalis/Homo-sapiens humans as a result, then they could not hv been a different species. Simply becos two different species cannot produce fertile, viable hybrid offspring when they interbreed.
 
Jan 2018
1,609
China (Hong Kong SAR)
Well, since they did interbreed with the more mainstream Homo sapiens, and indeed helped co-produce some fertile & viable hybrid Homo-neanderthalis/Homo-sapiens humans as a result, then they could not hv been a different species. Simply becos two different species cannot produce fertile, viable hybrid offspring when they interbreed.
That's an old and outdated definition, expect it to be gradually replaced in the future by more robust mathematical definitions concerning DNA with the awareness of statistical distributions within population samples.
 

sparky

Ad Honorem
Jan 2017
5,012
Sydney
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the usual definition of a specie is that coupling would produce fertile grand children
a sub-specie is a race carrying an inherited distinct morphological difference
IE the Eastern European crow and the Western one
this is fluctuating quite a lot as to geographical extend and a fair bit of interbreeding on the margin
 
Dec 2017
308
Regnum Teutonicum
Well, since they did interbreed with the more mainstream Homo sapiens, and indeed helped co-produce some fertile & viable hybrid Homo-neanderthalis/Homo-sapiens humans as a result, then they could not hv been a different species. Simply becos two different species cannot produce fertile, viable hybrid offspring when they interbreed.
Then how do you explain the amazon mollys or other sexual parasites, I mentioned in the first post?


Alright, if species don't exist, then start your ant-horse hybrid colony, as apparently, the ants and horses are one and the same thing...
You equate no species = all the same (essentially one species). It doesn't mean that there are no barriers for reproduction. My opinion is just that reality is much more complicated than the species concept. For instance the endosymbiontic theory:
Two organisms you would describe as two species, which couldn't reproduce fertile or any offspring, "merged" and started reproducing a new type of organism.