Hybrids are not inherently wrong

[kaybee]

Dogs were derived from wolves via human-influenced selective breeding; hybridization doesn't really come into play since the dog didn't orginate from the mixing a wolf and some other non-Canis lupis canine species.

There are many in the scientific community who taxonomically consider dogs to be a sub-species of wolf (Canis familiaris having been revised to Canis lupus familaris).

A dog crossed with a jackal (Canis mesomelas) or even with a Canid from an entirely different genus such as a fox (Vulpes vulpes) or African wild dog (Lycaon pictus) would probably be more accurate examples of dog hybrids. Mechanisms in nature prevent these type of canine-hybrids from occuring.

[HorrorShowRot]

Great write up I learned a lot. And to be honest hybrids are neat :)

[Deleted User]

Since it is not "natural", at all, for fish to live in glass containers like we keep them, personally, I see no problem with hybrids that are produced for the added enjoyment of owners.

Recently, we got some blood parrot cichlids, and as probably most people who've owned them, they are already our favorite fish. They're like nothing we've owned in terms of fish when it comes to how responsive to us they are.

My real joy at what we see in our "parrots" has re-confirmed to me that we do also want a flowerhorn. I'd falling in love with with pictures and videos of them posted here, but then questioned did a "need" that kind of fish when I have my dogs as far as really beloved pets. These parrots showed me how nice a dimension that level of interactivity adds to the fishkeeping hobby.

To me, in aquarium settings, to really focus on what is "natural" really makes no sense. Not that I don't understand doing your best to mimic a natural enviroment, I do. But in our household size aquariums, we are not keeping the fish "natural" at all, no matter what we try. Some come closer than others but I do imagine we all fall pretty short of it being just like in nature. We keep these creatures for our own pleasure -- period.

Think about it also... how far removed man's best friend is from anything that could thrive (or even survive in most cases) in the wild. I don't think my shih-tzu's would last too long lost in the woods. Look at a shih-tzu and a greyhound. If you didn't know better, you wouldn't even realize they're the same type of animal. Dogs are a great example at what the hand of man does to variety in a type of animal.

Some hybrids I've met in addition to the parrot fish are mules, mini mules (OMG, SO cute) and zebra x horse hybrids. All interesting animals. None of which I personally might choose to own but at least in the department of mules, not something I'd try and keep a horse or donkey smart owner from acquiring.

As to the extreme fancy goldfish, like most of you, I'm NOT a fan. I love my basic, unhandicapped, able to swim and live happily fancy goldfish but have no interest in any of the extreme mutations. I do feel sorry for those fish, but they exist because there's a portion of the public who prizes them over the more regular looking sort.

[jimw/oscar]

Balloon mollies and bubbleeyed goldfish aren't examples of hybrids, but are in fact the result of inbreeding within a species.

Blood parrot cichlids are true hybrids, the males are infertile but the females produce eggs which can be fertilized by either of the parent species or another close enough related species.

[ILuvMyGoldBarb]

the males are infertile but the females produce eggs which can be fertilized by either of the parent species or another close enough related species.

Nope, not anymore they are not. Male parrots are quite fertile now and they can breed just as well as any other cichlid. Do a quick google search and you will turn that one up. That infertility ended about 6-7 years ago.

[jimw/oscar]

Nope, not anymore they are not. Male parrots are quite fertile now and they can breed just as well as any other cichlid. Do a quick google search and you will turn that one up. That infertility ended about 6-7 years ago.

Could be with a lot of engineered cross-breeding tweeking. But originally male BPs were sterile proving they were hybrids between two species. I used to have arguments with people who insisted they were inbred something or other but among vertebrates male hybrids are sterile, as wtih mules, ligers, etc.

I've noticed in some lines of BPs their jaws are much more cichlid 'normal' as well.

[ILuvMyGoldBarb]

Most parrots are still infertile, but there are still a number that are not and are capable of fertilizing eggs.

[Fishguy2727]

It is not true that male vertebrate hybrids are sterile. There tons of examples to support this (unless you disagree with the idea of species). If you read the original post that discusses speciation it should help.

[jimw/oscar]

It is not true that male vertebrate hybrids are sterile. There tons of examples to support this (unless you disagree with the idea of species). If you read the original post that discusses speciation it should help.

It depends on what working definition of species you are using. As you originally wrote..

If two species cross under their own will and produce healthy, fertile offspring, then by the biological species concept’s definition of a species they are actually the same species. They may look different or be currently classified as separate species, but those may be false classifications. This is such as tricky subject in science that many scientists do not even believe in the idea of a species. There are no definitive barriers in most cases so we as humans cannot make up barriers and definitions just so that things are easier for us to understand and we cannot pigeonhole them just to suit our expectations of simplicity. Evolution is not done. Things are constantly changing and species are still in the process of evolution, still changing. Some are definitely too different to hybridize. Others are barely isolated enough to be separate populations and subspecies, but since they look different (something that can change VERY quickly under natural selection) we decided to classify them as separate species. So if hybrids are healthy and fertile then the two populations are not actually different species, but different subspecies.

I can't think of an example of a vertebrate hybrid producing fertile male offspring. Crosses between wolves and dogs aren't true hybrids because they're the same species, same goes with various amazon parrot subspecies some people incorrectly refer to as different species. The various African lake cichlids which can produce the "assorted cichlids" we see in pet stores can't be in actuality separate species either if they can produce more colorful aggravations for purist fish keepers :-).

If the two groups in question produce offspring capable of breeding with themselves then the two parent groups weren't separate species to begin with.

[Fishguy2727]

True, if your definition of a species is a group of animals that can interbreed to produce fertile males, then obviously there will be no exceptions of different species producing fertile males.

Macaws can interbreed and produce fertile male offspring and those are between species, not subspecies.

Genetic evidence shows that the red wolf is actually a result of the grey wolf x coyote hybrid.

Mbunas and peacocks can cross to produce fertile males.

All this is why many biologists do not believe in the idea of a species, at least not the way we currently think of and define it. It is a circle: well, if peacocks and mbunas can produce perfectly healthy and fertile offspring then are they really different species? The answer is still yes to most scientists. In my Evolution class we went in to all of this and what scientists currently usually go by is the presence of natural breeding barriers. These can be behavioral and not just genetic (naturally in Lake Malawi subtle behavioral and visual differences allow all the different 'species' of mbunas and peacocks to find and mate with each other). Since Biology is a study of life in NATURE if the animals do not interbreed in nature then it doesn't matter what they will do when locked in cage with a member of the opposite sex of a different natural species.

So for a much simpler and easier to deal with definition of a species, a species of animal is usually defined as a group of animals that will NATURALLY interbreed to produce fertile offspring.

But I do agree, as humans we want to look at nature as if it is done and it is just our job to go out into it, look at it, and understand it. Unfortunately nature is not done and species are still changing, so they won't fit in our pigeon holes of ideas that we consider species.