You know what the neanderthals used to say…
“once you go homosapien, you never go back”.
or so I’ve heard.
Which may be literally true if we bred them out of existance!
DNA testing failed to confirm that humans interbreed with neanderthals. That statement is more substantiable than saying DNA testing proved that humans did not interbreed with neanderthals as my local paper stated.
Gaspode,
Are you telling me that people don’t cross-pollinate and whatever else farmers/scientists do to combine or add traits to plants when it crosses species?
I am no expert in this field, but I thought it was common practice for farmers/scientists to get better crops.
When you are saying people are criticizing the process, can you give me examples?
I am coming from a molecular point of view and I just know plants are a lot more forgiving when chromosomes don’t match.
And when talking about bacterias, well, let’s just say it is a whole new world.
Farmers and scientists certainly do cross-pollinate to add traits to plants, just as farmers hybridise Bos taurus, Bos indicus and Bisonus bonasus to add traits to cattle. Similar hybridisation has occurred with various animal species. There’s no disputing that hybridisation across both Species’ and Genera occurs. The point of dispute is whether such hybridisation is more common amongst plants than animals. Given the greater numbers of plant species it’s highly doubtful if this is true.
Added to this artificial human hybridisation does not alter the species concept. A species remains a species if fertile reproduction is impossible in the wild. Humans have successfully ‘cross-pollinated’ camels and llamas, this doesn’t make them the same species because it’s completely artificial. Ditto with most plants. In the wild plant species often don’t hybridise because their flowering cycles are completely out of synch and never overlap, which is very similar to the reasons why cattle and bison don’t reproduce in the wild: the mating signals are out of synch. Horticulturalists overcome this in plants by using artificial lighting and hormones to synchronise flowering or by preserving pollen artificially. Similarly animal breeders use AI to preserve sperm and overcome asynchronous breeding cycles in animals. I seriously doubt however if natural cross-species hybridisation is any more common in plants than it is in animals (this has to take into account the massive number of plants vs. the piddling number of animals). Thus the species concept is as valid for plants as for animals based on that particular criterion.
Re- people criticising the plant species concept. I’ll see if I can dig up the original article but basically the criticism was that plants whose cycles were out of synch or that are isolated geographically and that had developed minor trait differences due to this can be very close geneticially and completely fertile if pollination does occur, but still designated as different species. The criticism was that this is completely artificial because changes in climate can, and apparently have in the past, caused re-synchronisation of flowering or allowed geographic re-integration and hence the species barrier is only a short-term phenomenon. These races shouldn’t be given separate species status just because plants are immobile, live longer than animals and are less mobile and hence exposed to more long-term climatic extremes and are more rigid in what promotes reproductive ‘cycling’. We consider Asian and American wolves to be the same species despite geographic isolation, asynchronous breeding and phenotypic differences because we know that if we lock them in the same reserve they will hybridise. However their are numerous plant species around the world that are completely fertile, synchronous in reproduction when in the same environment and have only minor phenotypic differences, yet are designated different species because they don’t reproduce in the wild. The European and American plane trees are classic examples, as are a complex of either five or six eucalypts in northern Australia.
I don’t doubt that plants are more forgiving of chromosomal mismatches, if only because polyploidy is so common naturally, but that probably doesn’t mean that hybridisation in the wild is more common.
Basically the whole species concept is arbitrary.
Gaspode,
THank you very much for your detail explanation.
I should go back to bio 1o1 as I forgot that species don’t breed with other species in the wild. Not the same as species cannot breed. My wording is way wrong, but this is for my info rather for others to read. aka too lazy to retype and think. 
Thanks again.