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This was inspired by a show in which two different kinds of dogs, who were neighbors, "dated," in order to bring their human neighbors together. This is a theme seen in Disney's "101 Dalmations" or "The Lady and the Tramp."
Can dogs of similar sizes, say Rotweilers or pitbulls actually interbreed? Can any of them mate with say, wolves? And under what circumances?
(I am "encouraged" by the fact that horses and donkeys can produce mules, and lions and tigers can produce "liger" or "tigons." Also of note is that dogs are of the same species as wolves, and "domestic dogs" are actually a subspecies.)
Yes, the vast majority of dogs out there are not pure bred. They are therefore a cross between two breeds. Consider cockapoos for example. The offsprings of a Cocker Spaniel and a poodle is called a cockapoo.
An intact female dog generally comes into heat twice a year, approximately every six months. Small breed dogs experience more estrus cycles, perhaps as many as four per year. Very large breeds, such as great Danes, might only come into heat annually. Most dogs reach puberty at about 6 months of age. You'll notice a bloody discharge when the cycle starts, but your dog shouldn't get pregnant at that stage. Between a week to 10 days into the cycle, when the discharge becomes watery, the dog ovulates. However, there's no truly safe time during heat when she can't get pregnant, because every dog's body is different.
Once female dogs start ovulating, egg release continues over several days. Sperm can survive in the reproductive tract for a week after mating. This means if your dog mated with one dog shortly before ovulation, she could still become impregnated seven days later. Breeders usually recommend two or three matings over a few days to ensure pregnancy. Accidental breedings with different males can just as easily occur over that time period.
A. “Many birds occasionally mate with members of other bird species, producing hybrid offspring,” said Irby J. Lovette, director of the Fuller Evolutionary Biology Program at the Cornell Lab of Ornithology.
In fact, Dr. Lovette said, about 10 percent of the world’s 10,000 bird species are known to have bred with another species at least once, either in the wild or in captivity. For example, in the eastern United States, native black ducks have hybridized so often with the more abundant mallard ducks that pure black ducks have become rare.
Hybridization tends to occur between species that are closely related, Dr. Lovette said, but an individual from one genus may occasionally form a pair with a bird from an altogether different genus, separated by many millions of years of evolutionary divergence.
Some groups of birds are particularly prone to hybridization, he said, adding:
“Experienced bird watchers know to watch out for the occasional hybrid gull or duck that exhibits an odd mix of its parents’ colors and behaviors. Often, however, hybrids die young, and even when hybrid offspring survive until adulthood, they may be sterile or have trouble attracting mates.”
When hybrid offspring do not pass on their genes, the mating that produced them cannot be considered totally successful from an evolutionary perspective, Dr. Lovette said. Indeed, much of the entrancing diversity of the avian world, like colors, plumes, songs and bizarre mating displays, “has arisen in part because these differences help female birds avoid accidental matings with a male of a different species,” he said.
Can different breeds of dog. breed?
Not to say it would be some easy coding task, but he could just have puppies inherit breed from the mother or father. Wouldn't need to worry about any sort of mixing then.
actually it's fairly simple. The code defines a 'race' and a 'pawnKind'.
Each race can have multiple pawnKinds, and pawnKinds in the same race can interbreed. In vanilla, pawnKinds are only used for humanoids (e.g. raiders, spacers, pirates, captains, grunts, etc. are all pawnKinds in the human race).
In vanilla RimWorld each animal has a unique pawnKind and race. However, most of the relevant stats, including the graphics to use, are defined in the pawnKind, not the race. That means it's entirely possible for all dogs to simply be a different pawnKind with the same base race.
I actually did this (by accident) for my Cats! mod, which is sadly long since out of date, but I don't believe the mechanics have changed there. The offspring will simply inherit the mother's race.
Now, dynamically coming up with half-breed races (and beyond) for offspring is a completely different task, and something that doesn't work well with the way races and pawnKinds are statically defined. Youɽ have to create these definitions during play, but that may break vanilla and modded code in many places, because it is generally assumed that definitions do not change after the game has started. Then there is also the problem of dynamically generating textures, which I'm sure is possible, but probably not feasible.
The other approach (which I believe GeneticRim also takes) is to pre-define a number of possible combinations that may happen. That works, but it's a lot of manual labour (textures and definitions for different combos), and it's not going to be moddable (each modded animal would require a patch to enable halfbreeds with it, and youɽ have an exponential expansion if you want to allow all modded animals to interbreed).
Can birds mate with other kinds of birds like dogs, cats, etc?
It may just be a mammal thing. Or just a cat/dog thing. But could ravens and mockingbirds mate just like a basset hound and a chihuahua could and produce living offspring?
As some others have pointed out, there is a huge discrepancy between "dogs" and "birds." Dogs were domesticated on the order of tens of thousands of years ago and all the breeds have arisen due to artificial selection they are all the same species (all the same sub-species even). Birds on the other hand, originated on the order of hundreds of millions of years ago, and have diversified into some 10,000 different species through natural selection, drift, and mutation (which together are far slower than artificial selection).
So while it is certainly true that both bird hybrids and dog "mutts" exist, it doesn't really make sense to compare the two groups directly. Ravens and mockingbirds diverged around 50 million years ago while basset hounds and chihuahuas were breeds that originated within the last 3000 years.
An interesting comparison to make though is the average divergence time between hybridizing birds and hybridizing mammals. Bird hybrids can be formed between bird species that diverged 20 million years ago while mammals can only hybridize with species that diverged up to about 2-4 million years ago (Prager 1975, Fitzpatrick 2004). Much debate has focused on why this difference exists, but one hypothesis is that it may be due to the different types of mating strategies that the two taxa are exposed to. Bird species tend to be isolated more by prezygotic barriers (think of mate recognition by plumage or song) whereas mammals tend to isolated more by postzygotic barriers (hybrid sterility and inviability). The "average time to hybridization" metric that we're discussing is a measure of hybrid inviability - a postzygotic barrier. As such, "good species" of birds may be able to evolve due to strong prezygotic reproductive isolation while still maintaining the ability to hybridize. Mammals on the other hand, don't evolve "good species" unless postzygotic reproductive isolation is present.
While this seems like a good theory it doesn't necessarily explain why one taxa would "favor" one type of reproductive isolation over another. Another theory that gets around this conundrum is that mammals show faster rates of regulatory evolution (as opposed to coding sequence evolution) than birds (Wilson 1974). Wilson argues that rapid regulatory evolution may give rise to faster evolution of postzygotic isolation than prezygotic isolation.
Despite these good theories, it is still unclear why birds can hybridize between very divergent species but mammals cannot.
Fitzpatrick, B. M. 2004. Rates of evolution of hybrid inviability in birds and mammals. Evolution 58:1865-1870.
Prager, E. M., and A. C. Wilson. 1975. Slow evolutionary loss of the potential for interspecific hybridization in birds: a manifestation of slow regulatory evolution. Proc. Natl. Acad. Sci. 72:200–204.
Wilson, A. C., L. R. Maxson, and V. M. Sarich. 1974. Two types of molecular evolution. Evidence from studies of interspecific hybridization. Proc. Natl. Acad. Sci. 71:2843–2847.
A Long-Busted Myth: It's Not True That Animals Belonging To Different Species Can Never Interbreed
Mules are infertile, but this is not true of all interspecies offspring. Illustration from the . [+] magazine The Illustrated London News, volume XLIV, August 20, 1864.
On 22 August, an astonishing discovery was reported. A sliver of bone from a cave in Russia turned out to belong to a hominin, one that was utterly unprecedented. Denny, as she is known to the scientists who are studying her, was a first-generation hybrid. Her mother was a Neanderthal and her father a Denisovan. She was a child of two species. The findings were reported in Nature.
I covered this discovery, as did many others, and within hours the question arrived: "I thought the definition of a species was that they couldn't interbreed?"
Many people seem to believe that animals belonging to different species cannot breed together, and that this is what defines a species. I suspect many of us acquire the idea in childhood when we learn about mules. The offspring of a horse and a donkey, a mule is a useful working animal but is entirely sterile and incapable of breeding. We all seem to generalise from this and assume that no interspecies pairings can produce fertile offspring.
This is not just a piece of folk science. The biologist Ernst Mayr proposed in 1942 that a species is a population of organisms that can all interbreed with each other, and which either cannot or do not interbreed with anything else. This idea became known as the Biological Species Concept, and evidently many of us learn it as fact.
The thing is, Mayr's idea is not accepted as the be-all-and-end-all by other biologists. Instead, the problem of how to define a species is still being argued about today, 76 years after Mayr published his definition.
Let's come back to mules. They are not a terribly good example of what happens when two species interbreed. Horses have 64 chromosomes and donkeys 62, so when the two breed their mule offspring ends up with 63. Because this is an odd number, it's impossible for them to divide evenly into two. That means the mule cannot produce sperm and egg cells that carry exactly half the animal's chromosomes, as should happen. When these defective sex cells are fused with those of another mule, the resulting embryo is likely to have crucial chunks of its DNA missing, and will not be viable.
However, many distinct species have the same numbers of chromosomes. For instance, all great apes (apart from humans) have a total of 48 chromosomes, arranged in 24 pairs. All else being equal, that means it ought to be easier for them to interbreed than it is for horses and donkeys.
So it has proved. Chimpanzees and bonobos have interbred several times since their populations split a few million years ago, and the bonobo genome also carries DNA that seems to have come from a third, unidentified species. Other ape pairings don't seem to have happened, but that might be partly because they live in separate habitats and don't meet: orangutans are confined to Borneo and Sumatra, and are unlikely to encounter gorillas and chimpanzees from Africa. But the idea captivates people: there are long-standing (unsubstantiated) rumours of a chimpanzee-gorilla hybrid called the koolakamba or kooloo-kamba.
Similarly, human evolution was rife with interspecies sex. Modern humans have interbred with both Neanderthals and Denisovans, Neanderthals and Denisovans interbred, and Denisovans interbred with an unidentified hominin. There is reason to suspect that the first-generation hybrids had some health issues, such as reduced fertility, but they were evidently able to get by well enough to leave descendants. Today many people carry some Neanderthal and/or Denisovan DNA.
This illustrates the problem with Mayr's species concept: where do you draw the line? If two animals can produce offspring, but that offspring's fertility is reduced by 10 per cent, are the parents members of different species? What about a 20 per cent drop in fertility - or a 10 per cent drop in fertility combined with a 20 per cent reduction in average lifespan? We could insist that the offspring be 100 per cent infertile, but that would mean collapsing a lot of species that we currently think of as distinct, beginning with chimpanzees and bonobos. Insisting that no offspring are produced at all would destroy even more distinctions.
Species are often separated, not by reproductive anatomy or courtship habit, but by geography - and those separations are reversible. In the lakes of the European Alps, pollution has caused oxygen levels to crash in the deeper waters, forcing the species that once lived there to move closer to the surface. There they have begun hybridising with longstanding surface-dwellers. These species had been separated for millions of years, but they weren't distinct enough to be unable to breed.
In fact it has been estimated that 88 per cent of all fish species could hybridise with at least one other, given the opportunity. The same may be true of 55 per cent of all mammals.
This hybridisation has a mixed environmental legacy. On the one hand, extinct species are not quite gone, because their DNA lives on. This is true of Neanderthals, and on Monday it emerged that it is also true of cave bears, whose DNA lives on in brown bears whose ancestors mated with the cave bears. Many of us would see that preservation as being somehow good.
But on the flip side hybridisation can also destroy species if two distinct groups breed so much that they blur together. This is what has happened to many of the fish in the Alpine lakes, and it may be the fate of polar bears if they are driven south by melting ice and begin interbreeding with other bears in a big way.
The lesson is that we should not become too wedded to concepts that we ourselves created. The idea of a "species" is a human construct, and while it's useful it doesn't map neatly onto nature. In this respect it is like the concept of "life", which most of us intuitively understand but would struggle to define. Or consider this philosophical passage from science fiction writer H. G. Wells:
"Take the word chair. When one says chair, one thinks vaguely of an average chair. But collect individual instances, think of armchairs and reading chairs, and dining-room chairs and kitchen chairs, chairs that pass into benches, chairs that cross the boundary and become settees, dentists’ chairs, thrones, opera stalls, seats of all sorts, those miraculous fungoid growths that cumber the floor of the Arts and Crafts Exhibition, and you will perceive what a lax bundle in fact is this simple straightforward term. In co-operation with an intelligent joiner I would undertake to defeat any definition of chair or chairishness that you gave me."
Other human concepts can be more tightly defined and delineated, but they're normally found in physics, not biology. There is no blurry dividing line between an up quark and a down quark, but there really is a halfway house between a horse and a donkey.
Finally, here is a truly exasperating fact. Once in a blue moon, mules do reproduce.
ELI5:How can different types of dogs look so different from one another but still be genetically similar enough to breed?
I know that there is much more to the story then just looks alone, but how can animals that look so different such as a chihuahua and a german shepard can breed but not something like a squirrel and a ferret? How can they be genetically similar enough to still be able interbreed with all the physical distinctions between the different breeds? How are there no different subspecies rather then just breeds of the same species?
And sorry if similar questions were asked but they did not cover exactly what I'm looking for.
Dogs have more variety in their appearance than any other species. It's easy to change their appearance through selective breeding, because their DNA contains an unusually large percentage of short-tandem repeats, so even a minor change is replicated many, many times.
Most of the dog breeds you are familiar with today didn't exist 300 years ago. Dogs have been under extreme artificial selective pressure for certain very visible traits during that time, while the vast majority of their genes are left unchanged for the most part. Meaning they look much more different than they actually are. Technically dogs aren't even a species, they are a subspecies (canis lupus familiaris) of gray wolves.
How can they be genetically similar enough to still be able interbreed with all the physical distinctions between the different breeds?
Because genetics and surface physical characteristics aren't the same thing. Lemonade and urine may look similar, but chemically they are different enough that you certainly wouldn't consider them equivalent. Genetics are governed by the chemical interaction between the DNA, not by how the creatures appear.
Genetically a squirrel and ferret are much more different than various dog breeds, despite being superficially more similar.
Can all dogs cross-breed? November 11, 2004 9:28 AM Subscribe
Yes, but not necessarily easily. For a Chihuahua dog to get it on with a Great Dane bitch, he'd need to be on a ladder, probably even the object of his affection was lying down. You could certainly get a breeding with artificial insemination.
You'd almost certainly have to have the bitch be the big dog.
posted by ROU_Xenophobe at 10:04 AM on November 11, 2004
we have a chihuahua cattle dog mix. if you have an accommodating female and an adventuresome male, anything is possible.
aside from looks (bug looks like a miniature cattle dog) what's interesting how the behaviour differs. he's very much a herding dog and has few chihuahua tendencies. he apes the behaviour of our other chihuahua, but you can see he's somewhat confused by it -- "what's with all this licking?"
posted by heather at 10:36 AM on November 11, 2004
all dogs are the same species, canis familiaris, which is pretty much a neotenous wolf - you could crossbreed a chihuahua with a timber wolf if you were so inclined, and you'd get puppies out of the deal.
(probably funny looking puppies, but puppies nonetheless.)
only reason domestic cats and wild cats look so much alike is that the face doesn't change much from kitten to adult. wolf pups look very different from the adults, lots of facial growth genes that can be modified through selective breeding to give us the weird variety of dogs we have now.
(that and the fact that cats aren't domesticated. they really are wild. only change we've made with cats is to give them a friendlier "meow" through breeding - otherwise they're the same as their wild relatives. dogs on the other hand have much smaller brains than a wolf.)
posted by caution live frogs at 12:06 PM on November 11, 2004
I've always wondered what would happen if you crossed a chihuahua and a mastiff. Would you get the world's largest yappy dog, or an unusual focused little dog?
/me pulls out a stepladder, puts on the Barry White, hopes to find out
posted by Captain_Tenille at 1:57 PM on November 11, 2004
"Accommodating female and an adventuresome male" can explain SO many things.
This is Bug, btw, our Red Heeler / Chihuahua mix.
posted by fraying at 3:04 PM on November 11, 2004
Two unusual crosses I know:
May Ren rest in Peace. Ren was a Dashund/German Shepherd cross. Ren's mother was the shepherd. Ren had stumpy little legs, a medium size body, shepherd head with one floppy ear and a shepherd tail. The funny thing with Ren was that he had no stomach to rub. He had chest and genitals. Poor boy left funny trails in the snow.
Ren's owners, good friends of mine, own another unusual cross. Maddy is half Black Lab and half Shar Pei. She's all black, even her tongue. She looks like an undersized Lab with a rat like tail. Maddy's got these odd, long hairs sticking out from her otherwise smooth coat. Maddy's wrinkles aren't evident until she perks up her ears. When she does, her face seems to collapse on itself. She's a sweet, sweet dog who is death to chipmunks and rabbits.
posted by onhazier at 6:25 AM on November 12, 2004
We saw a Basset Hound-Lab in the park the other day. Looked like a solid black basset hound.
My beloved, Fanny, is 3/4 English Bulldog, 1/4 Boxer and looks just like you would expect. Long skinny legs on a stocky bulldog body. Boxer coloring with bulldog face.
posted by Secret Life of Gravy at 9:33 AM on November 12, 2004
Puppies should be fed properly, even though they can eat anything it is best to feed guppies with a high-energy diet. Until the feeding conditions are not proper the guppies won’t go for breeding. The swimming and continuous movement in the water requires energy that comes from food. If you are keeping your guppies in a pond, aquarium, or tank that means now they depend upon you for proper feeding. So, if you want your guppies to breed properly, you need to feed them properly first.
Water conditions should be ideal the temperature should range between22 to 28 degrees Celcius and the pH levels should be between 6 to 8. The disturbed pH and salt levels can disturb the normal functioning of the guppies. Therefore to properly feed them and properly maintaining suitable water conditions is really important in the breeding of the guppies.
Guppies require clean water to be saved from stress conditions like fungal infections or many microbial infections that come with nonhygienic conditions that may disturb the normal functioning of the guppies. That is why you should treat your guppies with care and manage them well so they can breed easily.
Also, keep in mind that you provide guppies with sufficient space to swim easily. Guppies can breed throughout the year so it is essential to out them in vast spacious places. Guppies have small sizes, that is why even the 20-gallon tank size can be sufficient for the guppies.
Can different kinds of goldfish breed??
Hi everyone, I'm fairly new to this whole fish thing but I've been learning fast. I just picked up my new 12gallon Eclipse (bio-wheel) tank with some great halogen lights and stuff. I've finished establishing the bacteria levels and am finally ready to add some fish. In case you couldn't tell I love fantail gold fish and veiltails are cool too, but I kinda want to get a male fantail and a female veiltail and eventually breed them. Whats going to happen, mutants or will they just not breed??
Well originally I made the mistake of listening to the folks down at Petco which said that their $29.99 special for the "Starter 2.5 gallon kit" was big enough for my two fantails. You can imagin what happend to them, so the 12 gallon is a huge improvement and is really all I have room for.
12 gallons for 2 fancies will be tight for adult sized goldies. so just buy babies for now, it will give you a couple years before you should look at a 20 gallon. Just keep your eyes open at garage sales and bargain finder magazines, you can usually find them pretty cheap.
Regular water changes, say 33% once a week will also help keep the fish healthier in a smaller space. If you don't have one already, a water siphon/gravel cleaner is a must have for easier water changes. Your LFS clerk can show you how they operate.
Just buy a 3 gallon pail, use the siphon to remove the water till it's full. Then dump the water out (I reuse old tank water for watering plants), rinse the pail, re-fill it with tap water about the same temperature, add dechlorinator (I use PRIME brand - red label), and pour it slowly back in.