A second silent spring awaits the wolves at Isle Royale, a tacit death knell for the struggling inbred population. There were no puppies born in 2012 and last summer when the puppies should have undenned and filled the island with their distinctive yips, none were heard to mark the presence of another generation. This last winter no new wolves were counted during the yearly census confirming the fears that 2012 would be the first year in 50 that no new wolf life would grace the island; this year could be the second.
June marks the earliest that scientists would expect to hear the vocalizations if a litter was born this year. None reported so far. The possibility for pups remains as researchers believe that half of the 8 wolves on the island are female and although the population now is as low as it has ever been in the half-century of study, the balance of males and females means that regrowth is possible. Some females were spotted out of their dens earlier in the spring which signals that they likely didn’t have a litter.
Beyond the spinal malformations you’re probably aware of, additional inbred diseases are becoming apparent in the population. Some wolves are being spotted with clouded eyes and a female wolf was found dead in her den during the 2009 winter having birthed only one of her litter, the first time a failure to whelp causing death has been observed in a wild wolf. The population has fallen every year since.
The Isle Royale wolves were once central to the debate over how significant inbreeding is in wild wolves and just how detrimental inbreeding depression could be. Amazingly some wolfaboo scientists were inbreeding depression denialists, although history and re-examination of their studies has not helped their position. The debate now is shifting to what should be done, if anything to remedy the situation on the island which few believe will turn itself around.
I’ve written before about how inappropriate it was that inbreeding apologists were using the Isle Royale wolf population as an example of animals that are either adapted to or unaffected by high levels of inbreeding. The wolves are on the brink of extinction, so time has bolstered this observation.
It’s an open question if and how much the influx of new genes has changed the bone deformities which had come to define Isle wolves. Surprisingly, before the results of the bone study were published, Isle Royale was used as an example of a wild population that was thriving and unharmed by inbreeding and isolation. This is why I’m cautious of anyone who argues from ignorance regarding their ability to inbreed and avoid disease. This is the third lesson: don’t assume that inbreeding can exist in high levels without detriment and don’t cite wild populations if no one has ever done a detailed health study to document the true health of the population.
Professor Linda Laikre in the Division of Population Genetics at Stockholm University prechoed* this sentiment over a decade ago:
Several misconceptions exist regarding inbreeding and the conclusions that can be drawn from the kind of studies of captive animals presented here, and unfortunately these misunderstandings appear to be fairly widespread. I discuss a few of these misconception in some detail because of their importance in practical conservation management.
The view that carnivores, and particularly wolves, regularly reproduce with close relatives in the wild still seems to be common. It is surprising that this notion is so difficult to change because it is based on weak argumentation.
First, it has been speculated that the effective population sizes of carnivore species in general are small (WATHEN et al. 1985; CHEPKOSADE et al. 1987), that the social structure of many carnivore species such as that of the wolf promotes close inbreeding (MECH 1970, 1987; SHIELDS 1982; HABER 1996), and that inbreeding does not pose a problem to wild wolves (SHIELDS 1983; MECH 1995). As pointed out by RALLS et al. (1986) there are no empirical data supporting these speculations. For instance, in their extensive literature review RALLS et al. (1986) could only find one occasional observation of a mating between wolves identified as close relatives (grandfather-granddaughter) in the wild (PETERSON et al. 1984).
Second, the results of a computer simulation study performed by WOOLPY and ECKSTRAND (1979) have been taken as evidence that wolf packs are highly inbred. The weakness of this study is also discussed by RALLS et al. (1986).
Third, the situation at the Isle Royale (Lake Superior, USA), where a single wolf pair is believed to have founded a population which has persisted for five decades is frequently referred to as an example indicating that wolves are adapted to inbreeding (MECH 1995; SWEDISH ENVIRONMENTAL PROTECTION AGENCY 1997a). Wolf numbers at Isle Royale increased during the first three decades to a maximum of approx. 50 individuals, but has dropped considerably on several occasions during the last 20 years (PETERSON 1997). For instance, the winter 1997-98, 13 of a total of 24 animals died (ENVIRONMENTAL NEWS NETWORK 1998). To consider the Isle Royale case as a proof of wolves being adapted to close inbreeding disregards several facts: i) the effects of inbreeding on various traits have not been studied in this population, ii) it is not clear that the repeated drops in population size are not coupled with genetic factors (WAYNE et al. 1991), iii) even if the wolf population at Isle Royale should prove to be insensitive to inbreeding this observation cannot be used to conclude that wolves in general are adapted to close inbreeding.
The occurrence of inbreeding depression in a wild animal species bred in captivity provides clear indications that this particular species is not adapted to close inbreeding. This conclusion is obvious to a geneticist, but is frequently questioned by, for instance, wildlife managers and behavior specialists, who express the idea that genetic studies on animals in captivity are not relevant to those in the wild (e.g., SWEDISH ENVIRONMENTAL PROTECTION AGENCY 1997a).
This misconception may stem from the fact that conclusions regarding behavior of animals in the wild may not be possible to draw from behavior observations of captive animals. In contrast to behavior, however, the genes are the same whether the animal is free or held in captivity. Of course, it is not certain that the same type of inbreeding effects occur in every population.
If and how inbreeding depression is expressed depends on the particular genes that the individuals which are inbred carry. For instance, in a recent study of two captive populations of Mexican and red wolves no effect of inbreeding on juvenile survival and litter size could be detected (KALINOWSKI et al. 1999). This does not mean, however, that other characters in these populations are not affected by inbreeding, or that other wolf populations are not sensitive to inbreeding. As a parallel to the skeptic question “even if inbreeding is harmful in captivity, how can we be sure that inbreeding will have the same effects in the wild?” one may consider a query like “this chemical substance has proven toxic in laboratory animals, but how can we be sure it will cause damage in nature?”.
Laikre, L. 1999. Conservation genetics of Nordic carnivores: lessons from zoos. – Hereditus 130: 203-216. Lund, Sweden.
Inbreeding apologists in the dog world love invoking the notion that wolves inbreed all the time and are just fine and not harmed. As is clear from the scientific evidence, this once common refrain is nothing more than an unsupported meme that is not backed up by empirical or observational evidence.
Scientists are fighting against this misconception because it has major implications on the structure and success of wildlife conservancy programs. Dog breeders should take note as these same principles are vital for the maintenance and rejuvenation of our breeds as well.
* prech·oed
past participle, past tense of prech·o
Verb
Statement of an idea prior to another source, especially when the existence of the first source is unknown to the second or less prominent. e.g. Archibald Carey prechoed Martin Luther King when he ended a civil rights speech with “from every mountainside, LET FREEDOM RING!”
REFERENCES:
Chepko-Sade BD and Shields WM, Berger J, Halpin ZT, Jones WT, Rogers LL, Rood JP and Smith AT, (1987). The effects of dispersal and social structure on effective population size. In: Mammalian dispersal patterns. The effects of social structure on population genetics (eds. BD Chepko-Sade and ZT Halpin) The University of Chicago Press, Chicago and London, p. 287-321.
Haber GC, (1996). Biological, conservation, and ethical implications of exploiting and controlling wolves. Conserv. Biol. 10:1068-1081
Kalinowski ST, Hedrick PW and Miller PS. No evidence for inbreeding depression in Mexican and red wolves. Conserv. Biol., 1999.
Mech LD, (1970). The wolf: the ecology and behavior of an endangered species. The Natural History Press, Garden City, New York.
Mech LD, (1987). Age, season, distance, direction, and social aspects of wolf dispersal from a Minnesota pack. In: Mammalian dispersal patterns. The effects of social structure on population genetics (eds. BD Chepko-Sade and ZT Halpin) The University of Chicago Press, Chicago and London, p. 55-74.
Mech LD, (1995). The challenge and opportunity of recovering wolf populations. Conserv. Biol. 9:270-278.
Ralls K, Harvey PH and Lyles AM, (1986). Inbreeding in natural populations of birds and mammals. In: Conservation biology. The science of scarcity and diversity (ed. ME Soule) Sinauer Associates, Sunderland, Massachusetts, p. 35-56
Shields WM, (1982). Philopatry, inbreeding, and the evolution of sex. State University of New York Press, Albany.
Shields WM, (1983). Genetic considerations in the management of the wolf and other large vertebrates: an alternative view. In: Wolves in Canada and Alaska: their status, biology and management (ed. LN Carbyn) Canadian Wildlife Service Report Series 0069-0031, 45. Ottawa, p. 90-92
Swedish Environmental Protection Agency, (1997a). Forslag till itgardsprogram-Varg (Canis lupus, Linnaeus 1758). (Suggested action program-Wolf (Canis lupus Linneaus 1978 (In Swedish), Stockholm, Sweden
Wathen WG, McCracken GF and Pelton MR, (1985). Genetic variation in black bears from the Great Smoky Mountains National Park. J. Mamm. 66:564-567.
Wayne RK, Lehman N, Girman D, Gogan PJP, Gilbert DA, Hansen K, Peterson RO, Seal US, Eisenhawer A, Mech LD and Krumenaker RJ, (1991). Conservation genetics of the endangered Isle Royale gray wolf. Conserv. Biol. 5:41-51
Woolpy JH and Eckstrand I, (1979). Wolf pack genetics, a computer simulation with theory. In: The behavior and ecology of wolves. Proceedings of the symposium on the behavior and ecology of wolves held on 23-24 May 1975 at the annual meeting of the Animal Behavior Society in Wilmington, NC (ed. E Klinghammer) Garland STPM Press, New York and London. p. 206-224.
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I’m sharing the crap out of this. I had never realized that people actually believe wolves & coyotes are inbred, but recently, someone stated this as fact. So your article is quite timely for me.
There is some evidence of an inbreeding depression in “red wolves” (park coyotes).now.
http://www.academia.edu/222131/Red_wolf_reproductive_demographics
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Heh, no doubt. Here’s the summary for those interested. You can’t run away from inbreeding depression.
I think the appropriate question to any researcher who claims “we didn’t find inbreeding depression” is “did you even look for it?” because it turns out the the answer is invariably “No.”
Heck with Isle Royale the inbreeding depression is so bad that you can see it from the planes. And that’s really the kicker, that they didn’t do any real direct health analysis of the wolves over the years, the inbreeding depression was only noticed via horrible deformities in the carcasses and when they started going blind. Well, if you’re not tracing health measures you’re not going to get health data and if you don’t have health data, you get what happened with Isle Royale. Idiots pretending that it was all fine and dandy and only realizing the issues way too late.
In 2010 I had a disagreement with a ridgeback breeder in Australia regarding inbreeding, and her argument was that wolves left to their own devices, often choose to mate with their own parents and siblings, aunts, etc; presumably making inbreeding in dogs okay.
Or “linebreeding”, which to me is just another way of saying “inbreeding.”
I wish I had had these stats handy at the time. I could have looked for it but I didn’t think it was worth the time. I just knew there had to be something wrong with what this person was saying. I won’t bother re-hashing the old conversation with her but if it DOES come up again, I’ll know where to find this. Thank you!
If you intentionally breed spinal problems into your dogs for cosmetic reasons you can not be trusted with basic questions of breeding ethics and logic. You’re too blinded by tradition and what other people are doing. Ask yourself, if your dogs didn’t have that feature would you add it? Then why are you keeping it in for no other reason than other people are or did do it in the past.
“In 2010 I had a disagreement with a ridgeback breeder in Australia regarding inbreeding, and her argument was that wolves left to their own devices, often choose to mate with their own parents and siblings, aunts, etc; presumably making inbreeding in dogs okay.”
Your ridgeback breeder was lying. Do a search on pubmed for ‘yellowstone wolves.’ This is a limited, reintroduced population, and it shows greater than expected heterozygosity, which is taken to mean that the wolves are actively avoiding breeding with close kin.
I have NEVER had a ‘wild animals inbreed all the time’ person be able to back up their assertion with real data. They inevitably produce either captive animal studies or studies relating to animals in a limited situation, like a small, isolated population, or a population that descends from just a few individuals. There are no stats on how many such populations simply become unviable and die out. These studies do not show that such animals CHOOSE to inbreed, only that they will do it when it is unavoidable, and that they do not have a strong inbreeding avoidance mechanism (look up African wild dogs.)
I have a study on an island population of some kind of sheep that is descended from just two individuals. These sheep exhibit heterozygosity of the MHC, meaning they are selecting breeding partners that are genetically different from themselves. An interesting example, which again does not show that these animals CHOSE to inbreed, simply that they did so when they had no choice, and exercised as much choice in partners as they could. The Foxes on San Nicolas Island are another example of a population which is genetically homogeneous but still maintains heterozygosity at the MHC due to mate choice.
Inbreeding avoidance is well-documented in canids.
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The other meme they like to bring up is island foxes, especially those on San Nicolas, but those aren’t like domestic dogs either. They have been able to maintain MHC diversity largely though intentionally breeding only with individuals that have different haplotypes.
Dogs and wolves are the same species, so you can make quite a few generalizations from wolf population genetics and extrapolate them into dogs.
Wolves don’t inbreed. Pups of both sexes typically disperse from natal packs, and some even travel hundreds of miles before they meet a mate and set up their own territory.
Similarly dogs historically traveled with people all over, and their genes were spread all over, as well as adding in the bloodlines of wolves they met.
http://retrieverman.net/2012/02/14/dogs-were-not-created-by-inbreeding-but-they-are-being-destroyed-by-it/
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Blame my blog post for distorting my comment here! LOL
retrieverman recently posted..A hyena is not a dog with a pseudo-penis
With regard to island populations. . . I’m sure some of them do inbreed for want of other options. And some of them go extinct, too. And some of them get refreshed, periodically, by an outsider washing up on the island. Has anyone ever looked at the genetic diversity of extinct island species?
The Tasmanian devil, which seems to be on the way out, low diversity is apparently part of the problem. “Analysis of 14 complete mitochondrial genomes from current and museum specimens, as well as mitochondrial and nuclear SNP markers in 175 animals, suggests that the observed low genetic diversity in today’s population preceded the Devil Facial Tumor Disease disease outbreak by at least 100 y.”
Webb Millera,1 et al, 2011, Genetic diversity and population structure of the endangered marsupial Sarcophilus harrisii (Tasmanian devil), PNAS available online at http://www.pnas.org/content/108/30/12348.long
I don’t see why there’s a debate about what to do on Isle Royale. The solution is bloody obvious.
I’m curious why the “violent” anger over inbreeding here? In and linebreeding is the method by which all species have attained uniformity. Ever wonder why zebras all look so similar? Well its not from outcrossing my friends! : )
All useful domestic animals that breed true have been developed by inbreeding. My own health tested (and healthy) dogs are highly inbred (and culled). That’s what Nature does – inbreeds and culls. Too many humans who call themselves “breeders” leave that little part out and then blame “inbreeding”. Inbreeding, as we all know, does NOT “produce” a problem. It only intensifies it, where as outcrossing keeps it in the population, but hidden, just popping up now and then. If a population is NOT healthy, than inbreeding will be disasterous for it. That’s not rocket science.
Most dog breeds today are highly inbred, usually from just a handful of foundation dogs. They CAN be healthy – that is up to the current breeders and how much they love the BREED compared to saving every single pup born. As the cowboys used to say about horses… “If you can’t shoe ’em and shoot ’em don’t have ’em”.
First, with the fixation of Zebra coat genes, you’re raising a concept which is better described under evolution, natural selection, and genetic drift than with inbreeding. So you really aren’t saying anything important or even relevant there.
As for the development of breeds, selection is the sine qua non tool. Not inbreeding. The cultivation of like things by some standard, no actual inbreeding is required. That inbreeding has been used in various degrees is not in dispute, lazy breeders often turned to related individuals instead of finding like characteristics in unrelated stock. Your argument is basically saying that plagiarism is required to write a book since in dog culture so many people regularly plagiarize and many did it in the past.
To the larger point that some number of breeds were “created” by inbreeding or refined or developed or what not, that’s really not a strong argument for the continuation of Victorian behaviors either. Breeds constructed under your assumptions, like the Cavalier King Charles Spaniels which are reputed to come from only a handful of founders with many initial mother x son type matings, were not conceived with the appreciation of what sort of founding population would be required to allow a breed to survive in a closed pool for longer than 50 years or 100 years or 200 years. Most breeds, if we are to view them as closed gene pools–like a species–would be considered endangered species. There are neither enough founders to provide the prerequisite genetic diversity to maintain breed health for the long term nor are there enough extant breeder dogs each generation to maintain what little genetic diversity is left, nor are people breeding puppies in sufficient quantities to find the healthier stock which might emerge out of such unsatisfactory demographics.
I’m really not interested in your own dogs. Unless you’ve taken a scientific study of them, documented their health, their COI, and their observed heterozygosity over generations and bred numbers in such a quantity to make mathematically significant measurements, then it’s just a bunch of talk. You can claim whatever you want, it has no value because it’s not verifiable.
You also invoke “Nature” inbreeding greatly and culling. Well, you’ll be hard pressed to find many dog breeds which mimic nature in their population dynamics. But if we are to talk about nature, where are the studies which document widespread inbreeding without detriment? Where’s your documentation that inbreeding is so prevalent, continued, and unharmful?
The notion that you can health test enough and cull enough to avoid problems is bunk. You’re full of it. There is no mathematical way for one person, or even a community of breeders, to breed enough puppies to then cull them effectively. Very few breeds have GLOBAL populations big enough for this, let alone under the same breeding program. And the truth is that there just aren’t enough health tests compared to actual diseases to make significant assessments that you’d even know what puppies to cull.
I don’t know why you feel the need to lecture me on what inbreeding does or does not do. Why don’t you read the many posts I’ve written on it before you decide again to create an off-topic side conversation where you retread issues which have already been covered here.
Start here: http://www.border-wars.com/category/health-genetics/inbred-mistakes
Continue here: http://www.border-wars.com/tag/inbreeding
..I really enjoy it when ‘sacrificial lambs’ folly about with you Chris..your rebuttals are quite rational pertaining and maintaining to fact and reason..
I can almost imagine them ‘huffing off’ exclaiming “..yeah, well Chris..well..you..you’re just cluttering the issues with facts! ”
😉
The funny part you don’t see is the links they arrive from where many of these people post things like “I just left the bestest comment EVAR! and it so destroys everything he says I doubt he’s even going to publish it!!!”
This one is no different.
http://ultimatepitbullforum.com/viewtopic.php?f=19&t=2380
“I’m curious why the “violent” anger over inbreeding here? In and linebreeding is the method by which all species have attained uniformity. Ever wonder why zebras all look so similar? Well its not from outcrossing my friends! : )”
Um…ever heard of a little thing called “natural selection”? Zebras (& all other wild species) look alike because that is the phenotype which has resulted in the largest number of offspring surviving long enough to breed successfully. Over time, anything in that environment which hasn’t managed to conform to a specific mold dies out. No inbreeding required (& thus almost none occurs). Until very recently, this was how most “breeds” of domestic animals were developed, too, but the selection pressures also included man-made influences. So you got your land races, populations of animals which strongly resemble each other because, over time, that has proven to be the phenotype which does well in a given environment.
Equids, like most species, have anti-inbreeding behaviors in place. Male offspring are run off by the current dominant stallion when they reach breeding age, & new stallions are constantly overthrowing older stallions for the privilege of breeding to their daughters.
Lastly, I fail to see any violent anger. I’ve never seen Chris advocate for a violent overthrow of the system or display a any irrational emotion. Strong disdain, certainly. Impatience with the dog fancy’s seeming inability to grasp the simple concept of population genetics, definitely. But not violence.
A breed that is classified as “healthy” because breeders just kill the unhealthy dogs produced every generation, that is not a breed that I would call healthy.
The killing of unhealthy dogs could be acceptable(depending on the severity of health problems). but the use of breeding methods that significantly increases the production of these dogs is not. Nobody with any sense of ethics, and a basic understanding of genetics, should accept inbreed and cull as valid way to breed dogs.
Another point which your “cull your way to health after inbreeding” strategy fails to account for is both the volume of extant deleterious alleles in every dog and the number of new mutations that occur every generation. I’ve seen it argued, and perhaps you believe this, that some breeders believe it’s crucial to inbreed and “reveal” the recessive genes.
This is horribly silly, since under smart breeding choices (and heck, even random ones) the vast vast majority of deleterious new mutations will never be inbred upon an rarely if ever double up. Positive mutations will confer advantages and have a better chance at slowly becoming established in the gene pool.
All things considered as well, your position is very arrogant. It assumes, against all reasonable proof, that humans have the ability to assess the benefits versus detriments of mutations and all genes for that matter. In reality, we are profoundly ignorant, so much so that the degree of our ignorance greatly outpaces the amount of our knowledge. Under this scenario, which will likely persist for thousands of years, we are better off to behave in a manner which minimizes the detriment from all the problems we DON’T know about, for even though we don’t know the details we do know how to behave to limit their effects.
That position also assumes that all problems or benefits are caused by simple recessives or dominants. Inheritance and expression are far more complicated than that.
Jess recently posted..I Think That About Sums It Up
I’d toss out a concept like pleiotropy, but I think that would result in chirp chirp chirp.
That’s because the arrogance necessary to being a dog breeder (I am going to pick this bitch and that dog according to their traits and I am going to produce something *better* than the parents) also makes dog breeders stupid.
I was once told (by a breeder who shrieked hysterically at me that she was ‘EMBARRASSED that her dogs were RUMORED to be behind some of mine!!!!!1!’) that “of course she knew all the genes behind her dogs and knew exactly what they would produce.”
How many litters had this person bred? Six, over nearly forty years.
Arrogance and stupidity combine to produce: “Inbreeding does not “create” problems – it just shows you what you have in your genetics. Nature has been inbreeding and culling (they must be done together) for an awful long time – that is why wild animals have such amazing uniformity. These guys are nut cases.”
Jess recently posted..I Think That About Sums It Up
“Nature has been inbreeding and culling (they must be done together) for an awful long time – that is why wild animals have such amazing uniformity. ”
It AMAZES me that people don’t grasp the concept of natural selection. They look alike because that genotype is what survives to produce offspring in that given environment. Critters that don’t manage to fit the mold don’t survive. Why is that so difficult to understand? I understood this concept when I was 5.
Evolution depends on genetic variation. No variation, no adaption.
Jess recently posted..I Think That About Sums It Up
” ‘Inbreeding does not ‘create’ problems – it just shows you what you have in your genetics. ”
Holy crap on a stick! You have NO idea how often I have been told that and how it KILLS me to hear!
Uh, so you’re going to inbreed intentionally just to SEE what horrors you may or will create????
THAT is what you are saying, moron breeder. So you basically KNOW inbreeding does bad things and you just won’t own up to it?
This is WHY inbreeding is wrong! Because it DOES cause these things!!!!! Just DON’T!!!!
Arrrrgh! Somebody please make me a margarita! I need to get away!
I’m confused about the NEW mutations part of this argument. What I remember from basic biology courses is that natural rates of mutation are very very low. My reading, which may be wrong, is that deleterious mutations such as the bob-tail, dwarfism, and merle alleles arose once or a few times, perhaps millions of years ago, perhaps before the dog became a dog…maybe even before the wolf became a wolf. Does the bob-tail gene that affects Manx cats stem from the same mutation event that brought bob-tail genes into dog populations? Are Balaev’s piebald foxes carrying genes from the same mutation event as dogs of similar coloration?
When mutations are benign when heterozygous, they are very weakly selected against in a natural population that avoids inbreeding. Thus they only rear their ugly heads when people start inbreeding and increasing homozygosity.
Do I have this wrong? Or is this another ‘no one knows’ question?
I think the concept that you’re stuck on is that new mutations in any ONE locus are rare. And, new mutations which don’t quickly disappear due to drift are also rare. Buuut, new mutations in general? Pretty common.
http://www.sanger.ac.uk/about/press/2011/110612.html
I’m comfortable with the idea that mutations are frequent. But the literature on mutation rates repeatedly says rates of mutation are much higher in some parts of the genome, and that many loci are strongly conserved, particularly those with functional implications. I’ve been trying to read (hard slogging but an interesting read) Anderson et al’s (2009) Molecular and Evolutionary History of Melanism in North American Gray Wolves, Science Vol. 323 no. 5919 pp. 1339-1343. These authors conclude that the K^B haplotype came into the canid genome before coyotes split from wolves, and has come into the N American wolf population through hybridization with dogs. Ie, black coyotes are not a mutant form of normal coyotes, they are carrying an ancient trait. Ie, the 60 mutations you or I are likely to carry will be strongly concentrated in ‘junk’ regions of our DNA. I don’t think we can say whether many of the things that are termed ‘mutants’ — eg., is the ‘rare mutant’ color budgee that is much sought after by breeders actually a mutant, or the chance product of a mating of two individuals carrying a rare recessive gene that arose from a mutation thousands of years ago? Same with Balyaev’s new fox colors…selection for tameness is likely to have resulted in greater homozygosity, and thus more expression of rare recessive genes. Or maybe it was pleiotrophy. I doubt it was a mutation.
P.s. here’s a paper that puts the effective mutation rate for the entire human genome at about 70 mutations /generation
http://www.genetics.org/content/190/2/295.full.pdf
They looked at differences between humans and chimps.
Questions:
1. How many species of zebra are there?
2. Can they all interbreed and produce fertile offspring?
I think that will show why there isn’t a lot of merit to what you’re saying at all.
Wolves have very high levels of inbreeding avoidance behavior. It’s so bad they will mate with coyotes and run hundreds of miles from their parents’ packs just to avoid inbreeding.
Dogs have not evolved to be inbred. They have evolved to have mating system based upon a breeding pair, which we have largely destroyed through domestication.
The delusion is that you can inbreed and purge all the bad genes with no unintended consequences. To be able to do what dog breeders claim to be able to do, you’d have to have more knowledge of the dog genome than the elite of elite among molecular genetics.
Inbreeding is a delusion in that in the short term it fixes traits, but in the long term, there are many, many unintended consequence.
Just look up the literature on how often wolves actually do inbreed and how strong their inbreeding avoidance behavior is.
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One of the problems in dog breeding is that we don’t let the females select their own mates. I have read a theory (don’t recall where) that animals are drawn to mates that have different different MHC profiles than their own. Hopefully in a few years the genetic tests will be able to provide that information so breeders can add that info to their considerations.
This has been found in humans, too. One study showed that women rate shirts worn by close male relatives as smelling less attractive than those shirts worn by men who are not related to them. The women in the study did not know who had worn the shirts.
According to this article, the Isle Royale wolf population is now down to eight (or maybe seven, not clear how Isabelle’s departure and death is counted) BUT three of the population are under one year of age.
http://www.latimes.com/nation/nationnow/la-na-nn-isle-royale-wolves-climate-change-20140228,0,3350160.story#axzz2vNArSL6E
Apparently there was a successful whelping in 2013. If the ice bridge of 2014 eventually does bring in fresh recruits, the population may yet linger.
(not to deny that inbreeding has made a mess of this population . . . just to say island populations may linger for a long time with occasional new blood from the mainland population).
Wild animals eat a varied diet and are exposed to more viruses than captive animals as viruses are airborne. Food and Viruses don’t change our genome and offer protection against inbreeding continuously in the long run?
I’m not sure that you can so easily say that wild animals eat a more varied diet than domestic. We might see kibble or whatnot as mush, but the realities of the modern market mean that what goes into pet food are meats and grains and legumes, etc. from all over the planet.
And speaking of diet and genome, I think it would be uncontroversial to say that diet can certainly change gene expression, but that doesn’t at all defend against inbreeding depression. Inbreeding depression is caused by the wholesale loss of genetic diversity via homozygosity. Gene expression, or epigenetics, can’t activate or not activate genes that are simply not there. Frankly the fetish over epigenetics is silly and myopic in this manner. Even if we give epigenetics great power to turn on and off expression, if you limit what is even available to express, the damage is done. It’s rather like saying being multilingual is the greatest, but then you only teach English. Well sure, the other languages exist in theory or existed, but they don’t exist in your current population, so there’s no way any of your current population can speak them. Only way to bring them back in is by bringing in genetic diversity to your population.
So food is not some magic fix. Frankly I think it would be obvious that domestic animals are coddled regarding food and more wild animals die of starvation (compounded by infirmity, disease, i.e. you get feeble and sick and can’t hunt, also making you easier prey) than perhaps any other issue…. so just lack of food in general is a major issue.
Now viruses actually do write themselves in to your genetic code. That’s how they work, they hijack certain cells in the body to replicate themselves and if they make it in to germline cells their dna can be passed on. Something like 5-8% of our genome is made up of ancient (deactivated via mutations) retrovirus DNA. And like half of our DNA is just really really old non-coding junk that we can’t even recognize as much of anything, much if it is perhaps even older viral trash.
Now, are wild animals exposed to more viruses than domestic? I’d say that being coddled by domestication allows more domestic animals to live longer than 2-3 years and thus even if we accept that somehow there is more exposure to a virus in an animal that lives in the wild (I don’t actually see any reason to believe this one way or the other without evidence), that domestic animals living longer by being sheltered are also more likely to be exposed to viral elements in total before they breed. And also perhaps because of the global-community transmission model… i.e. in many ways we are closer to humans (and thus their dogs) from across the globe than some wild populations are from animals mere miles away because our world is highly mobile and connected.
In other words, no, I don’t think food and viruses are protective of inbreeding in wild populations. Seems more like a conclusion looking for reasoning (i.e. anti-science) to me.
I am pro science and I’ve guinea pigged myself with a “variety” of food and different temperature environments for many years.
A “variety” of food and viruses does lead to genetic diversity. My siblings mostly eat land animals, dairy and grains. They aren’t attractive. I eat seafood, nuts, fruit and carrots. I’m tall, attractive and developed attractive lips after I was 25. My cranial increased in size from eating more omega fatty acids from high quality whole foods relative to saturated fat.
My hair use to be dark brown but since eating food with more arginine relative to other amino acids.. my hair started turning blond/light brown.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3481182/
Wild herbivores eat many different types of leaf vegetation as they migrate and these plants have their own unique genome which is then digested and incorporated into the genome of these animals. As plants and herbivores diversify… so do wild carnivores as they eat a variety of these animals. If animals within a group eat the same foods and breed… Then they will obviously suffer from inbreeding depression.
Another example is sled dogs having blue eyes from being fed fish instead of land animals.
Domesticated animals are always fed the same domesticated food. Hence very little genetic diversity and genetic disorders follow.
There is also the deficiency of Vitamin D factor leading to genetic mutations and a weak immune system.
https://blogs.scientificamerican.com/observations/vitamin-d-deficiency-linked-to-genetic-polymorphisms/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2906676/
If a variety of foods, viruses and different temperature environments doesn’t diversify our genome. What does?