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The seemingly endless weirdosity of the Milu

The views expressed are those of the author and are not necessarily those of Scientific American.


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Thanks to everyone who had a go at identifying the ‘mystery object’ I was recently photographed holding. Obviously, said object is an antler. So, well done if you got that bit right. But it’s a very weird antler.

It obviously comes from one of the larger deer species and is consistent in overall anatomy with a cervine (and not with any of the mostly North American odocoileines – the white-tailed deer, mule deer, brockets, moose, reindeer and so on). Unlike the majority of cervine deer, however, it lacks the relatively short brow and bez tines that normally project anterodorsally from near the base of the main beam. Instead, there are two roughly equal-sized branches, both of which are forked at their tips.

A variety of antlers from my personal collection, badly photographed. The main thing to note here is the presence of what seems to be a hypertrophied brow tine in the 'Elaphurus' antler.

This very distinctive anatomy is characteristic of the globally endangered, extremely peculiar Père David’s deer, David’s deer or Milu Cervus davidianus (previously Elaphurus davidianus). While the posterior branch of the antler is probably the beam, the long anterior branch is generally thought to be a massively enlarged brow tine, in which case the bez tine has been lost. I grew up knowing this species as Père David’s deer but now normally think of it as the Milu. I’ll use both names here as and when I see fit. Hey, it’s my blog.

Milu photographed at Greater Vancouver Zoo by Canuckle, from wikipedia.

The light brown colour of that antler, its large size and somewhat ‘woody’ feel and surface texture are also consistent with this identification, as is the fact that it comes from a collection of English antlers. In recent history, England has been as much the home of this distinctive deer as its native China. I can’t totally exclude the possibility that the antler isn’t from a freak member of another deer species (deer are notoriously plastic in antler development), but I think Père David’s deer is the most likely identification, and other people who have seen and handled the antler think this too. Well done Dartian, welsh peregrine, Sordes, puppygod, AnimalDoc, larajlcouldwell, PlatypusKimberly and everyone else who identified it as a Père David’s deer antler.

Late discovery, survival in captivity, salvation by exportation – a curious history

Reconstruction of the Taiwanese E. formosanus, by Tori Morris.

Père David’s deer has a particularly interesting (and oft-recounted) history (if you share my interests you’ll already be fairly familiar with it). Fossils show that the species previously occurred widely in China (Wu 1991) and also on Japan and in Korea. In addition, five fossil species thought to be part of the same lineage (and conventionally classified as additional species in the genus Elaphurus) have been named from the Late Pliocene and Pleistocene: E. bifurcatus from northern China, E. menziesianus from eastern China, E. akashiensis and E. shikamai from Japan, and E. formosanus from Taiwan [adjacent reconstruction from here on deviantart].

Due to unspecified reasons (but most likely hunting for the supposed aphrodisiac qualities of its antlers), C. davidianus became extinct in the wild about 1000 years ago (though read on), with only a single captive herd at Beijing’s Imperial Hunting Park remaining. Chinese people knew these deer by several names, including Milu (also written Mi-Lou) and Sibuxiang (also written Sze-pu-hsiang and Ssu-pu-hsiang). The latter apparently means something like “unlike the other four”, the “other four” being some combination of cow, deer, horse, donkey, camel and goat. Entrance to the park was forbidden on pain of death (Laidler & Laidler 1992).

The species remained unknown to European until the 1860s when Père Armand David – perhaps best known today for his discovery of the Giant panda Ailuropoda melanoleuca – learnt of that single captive herd, by then consisting of 34 animals. Heuvelmans (1995) says that David eluded the guards to the park and scaled the wall, thereby making sight of these deer for the first time (other sources say that he found a section of wall that was being repaired, and stood on a pile of bricks to peer over it). He later bribed the guards and managed to obtain a pair of antlers and two skins that he sent back to France; these were described by Henri Milne-Edwards in 1866 as a new species named in his honour.

One of the Duke of Bedford's deer, as figured by Richard Lydekker in 1903.

The Chinese herd then became the victim of misfortunate. In 1894 and/or 1895, flooding from the Han River swept through the hunting park, destroying part of the wall. Some of the deer escaped, but they were eaten by starving local peasants. Deer were also killed during the Boxer Rebellion in 1900 (Laidler & Laidler 1992, Heuvelmans 1995, Nowak 1999). Some sources imply that all of the deer were killed at this time, but it actually seems that the last of them survived at Beijing Zoo until 1922. And while convention has it that the hunting park herd was the only remaining population (that is, that the species was long extinct in the wild), Dobroruka (1970) reported two skins, collected on the island of Hainan (off the southern coast of China) in 1869. If this report is accurate, the species did actually persist in the wild much later than generally thought. Li et al. (2011) recently studied captive Milu herds to see if they still react to the predators they would once have lived alongside, and showed that they seem to respond to the tiger as a potential source of danger. Incidentally, I’m pretty sure that I recall seeing the Milu’s story portrayed in comic strip form on children’s TV during the 1980s – I think in the BBC series Blue Peter. Does anyone else know what I’m talking about?

Anyway, after 1922, the Milu was extinct in China. Fortunately, a number of individuals had been illegally exported to various collections in Europe. The Duke of Bedford became especially interested in this curious deer and, following the purchase of specimens from various collections, ended up with 18 of them. It is 11 of this 18 that formed the ancestral stock for the modern population of c. 2000. People began sending individuals back to China during the 1950s and herds were released into the wild in China during the 1980s. Somewhat surprisingly, inbreeding depression does not (yet) seem severe in these animals (Sternicki et al. 2003).

Fighting Milu stags. Photo by T. Voekler, from wikipedia.

Incidentally, England very nearly had its own feral population of Milu. In 1981, 12 members of a herd kept near Swindon in Wiltshire escaped simultaneously from captivity (Baker 1990). All 12 individuals returned to captivity, apparently of their own accord, but – had they bred – they could very well have established a wild colony. We already know that the Milu is easily hardy enough to survive in the wild in western Europe. Incidentally, the Milu readily produces hybrids with the Red deer C. elaphus, and the hybrids are readily fertile too. However, different breeding seasons mean that the two don’t ordinarily mate on contact, so hybrids have to be produced via artificial insemination (Tate et al. 1997). Hybrids are large (larger than average Red deer) and long-headed [one of these hybrids is shown below].

It looks weird, it acts weird

Père David’s deer is pretty weird looking. It’s a very large deer with highly pronounced sexual size dimorphism (males are typically about 214 kg while females are more like 150 kg). It has an especially long snout with a superficially cow-like face that appears to be peculiarly flat dorsally (Colin Tudge once described its face as “lugubrious”). Its hooves are especially large and seemingly not well suited for movement on hard ground: one of several features indicating specialisation for life in wet, swampy grassland. Its tail has a tassel at the end and is the longest of any deer. It has a shaggy coat, with long guard hairs being present throughout the year.

Milu stags engaging in parallel marching, their antlers adorned with mud and foliage. Photo by Jon McGowan.

Many aspects of its behaviour, biology and life cycle are odd. Many male deer spray their bodies with urine during the rut in order to make themselves as pungent as possible. Uniquely, Père David’s deer swings “the penis horizontally from side to side with an upward swing at the end of the traverse” (Geist 1999, p. 102). Males also seem to adorn their antlers with mud and vegetation more than other deer do, and it’s even been suggested that their peculiar antlers are somehow specialised for this sort of decoration (Walton & Hosey 1984). They roar often compared to other deer but various aspects of their dominance displays (especially the parallel marching) are much like those of Red deer and very different from those of the three-pronged Asian deer (axis deer, sambar and kin) they’re sometimes supposed to be closest to. Uniquely for cervine deer, males grow their antlers over the winter, shedding them in December or January. They’re also known to grow two sets of antler in a year, but only when extensive hand-feeding is provided.

Milu box in bipedal pose (note to self: must discuss bipedality in deer some time) and also bite with their fairly large canines. Females fight as well as males. I’m sure you all know that female animals fight (either against other females, or against offending males), but I just wanted to remind you – you sometimes get the impression from nature documentaries that aggression is just for the boys.

The weirdest deer – - the weirdest origin?

Exactly how Père David’s deer might be related to other deer has been somewhat controversial, as is admittedly usual for aberrant, weird-looking species.

Male Milu, by Lilly M, from wikipedia. Looks weird.

Partly this is because it combines features of various different deer groups. Geist (1999) suggested that Père David’s deer evolved from early, three-pronged, axis-style deer and that its large size and behavioural and morphological similarities with Red deer and so on were convergences. Pitra et al. (2004) found Père David’s deer to belong to a lineage that also included Eld’s deer C. eldi. This Eld’s deer + Milu clade was the sister-group to a much larger one that included the majority of other cervine deer (including the many forms of Red deer and Sika, sambars and axis deer).

Cervid phylogeny from Pitra et al. (2004). You should be able to see the Eld's deer + Milu clade near the middle of the diagram. Click to enlarge.

However, because the Milu combines features of Eld’s deer (including adaptation to swampy habitats, weird antlers that lack a bez tine, absence of a rump patch and presence of large canines) with those of more ‘advanced’ cervine deer like Red deer and Wapiti C. canadensis (it adopts a head-down dominance posture, is temperate-adapted, has tines on the beam that are nearly at right angles), it’s something of an anomaly in deer phylogeny. It could be a fairly primitive cervine that has convergently evolved ‘advanced’ characters, presumably as its ancestors moved into temperate climes. But could it be exactly what it looks like – that is, a weird (and self-perpetuating) hybrid between ‘primitive’ and ‘advanced’ cervine deer?

Well, this is exactly what Meijaard & Groves (2004), Pitra et al. (2004) and Groves (2005) have suggested. They think that an Eld’s deer-type maternal parent mated with a Wapiti-type paternal parent some time in the Late Pliocene, and that the Milu lineage is the result. Mitochondrial data puts Père David’s deer close to Eld’s deer, but studies of its y chromosome have yet to reported, so far as I can tell. According to these authors, it’s now most appropriate to sink Elaphurus into Cervus.

Italian sparrow, by I. Ivanov.

The idea that new species might arise via hybridisation from phylogenetically distinct parental species has become increasingly popular in recent years, mostly as molecular investigations have revealed genetic contributions from different parental ancestors in the genomes of some populations. Among tetrapods, classic examples include certain of the whiptail lizards, but the hybrid origins of Audubon’s warbler Dendroica auduboni (or D. coronata auduboni) and the Italian sparrow Passer italiae are now quite well known. We saw recently that the Wisent or European bison Bison bonasus (or Bos bonasus) might have arisen following hybridisation between members of the bison and aurochs lineages, and the recent discovery that Neanderthals and Denisovans have contributed to the gene pool of Homo sapiens also raises the possibility that our own species emerged after complex hybridisation involving more than two species.

More work is needed before we can be more confident about this hypothesis. It seems odd, but I don’t really see why it can’t be true: we already know that phylogenetically disparate deer lineages can produce fertile hybrids without problem, we know that hybridisation is not rare in the wild (despite what textbooks have taught you about the ‘biological species concept’), we know that those entities we term species can be produced in this way, and we know that Père David’s deer exhibits a curious mix of features that seemingly ‘belong’ to other lineages.

If this proposal is valid, what might it mean for nomenclature? Elaphurus has mostly been given its own ‘genus’ because it’s morphologically distinctive compared to other deer. The fact that it was potentially created by hybridisation doesn’t negate this; hybrids between distantly related parental taxa often look peculiar and we don’t go around given them distinct new taxonomic names, but I suppose we should if they become self-perpetuating lineages that persist for millions of years. However, the idea that Elaphurus (and Axis, Rucervus and Rusa) should be absorbed into Cervus has become increasingly popular lately due to phylogenetic work (Pitra et al. 2004, Groves 2005).

Milu x Red deer hybrid, from the cover of the issue of Journal of Heredity that included Tate et al. (1997).

And what would a hybrid origin mean for the depiction of cladograms and other evolutionary trees? Should the Milu be shown occupying two different positions on diagrammatic trees, or should we show lineages from the Eld’s deer group and Wapiti group merging to create the Milu lineage? These are just musings that I’m throwing out there for debate – I don’t especially have answers (though do note that cladograms are not generally meant to be evolutionary trees: rather, they’re schematic representations of branching sequences).

I’ve always had a great fondness of Père David’s deer, and I’ve long been familiar with its interesting back-story, its unusual morphology, and the controversy over its phylogenetic position. But I admit that I had no immediate plans to write about any of this stuff and have only ended up doing so because I happened to be given a box full of antlers about a week ago. I hope you find this very special deer to be as fascinating as I do, and thanks to those of you who had a go at guessing the identity of that unusual antler in the first place. Thanks to Richard Reeves for supplying the antler!

For previous Tet Zoo articles on deer, see…

Refs – -

Baker, S. J. 1990. Escaped exotic mammals in Britain. Mammal Review 20, 75-96.

Dobroruka, L. J. 1970. To the supposed former occurrence of the David’s deer, Elaphurus davidianus Milne Edwards, 1866, in Hainan. Mammalia 34, 162-164.

Geist, V. 1999. Deer of the World. Swan Hill Press, Shrewsbury.

Groves, C. 2005. The genus Cervus in eastern Eurasia. European Journal of Wildlife Research 52, 14-22.

Heuvelmans, B. 1995. On the Track of Unknown Animals. Kegan Paul International, London.

Laidler, K. & Laidler, L. 1992. Pandas: Giants of the Bamboo Forest. BBC Books, London.

Li C, Yang X, Ding Y, Zhang L, Fang H, Tang S, & Jiang Z (2011). Do Père David’s Deer Lose Memories of Their Ancestral Predators? PloS one, 6 (8) PMID: 21887286 [free pdf]

Meijaard, E. & Groves, C. P. 2004. Morphometrical relationships between South-east Asian deer (Cervidae, tribe Cervini): evolutionary and biogeographic implications. Journal of Zoology 263, 179-196.

Nowak, R. M. 1999. Walker’s Mammals of the World, Sixth Edition. The Johns Hopkins University Press, Baltimore and London.

Sternicki, T., Szablewski, P. & Szwaczkowski, T. 2003. Inbreeding effects on lifetime in David’s deer (Elaphurus davidianus, Milne Edwards 1866) population. Journal of Applied Genetics 44, 175-183.

Pitra, C., Fickel, J., Meijaard, E. & Groves, P. C. 2004. Evolution and phylogeny of old world deer. Molecular Phylogenetics and Evolution 33, 880-895.

Tate, M. L., Goosen, G. J., Patene, H., Pearse, A. J., McEwan, K. M. & Fennessy, P. F. 1997. Genetic analysis of Père David’s x Red deer interspecies hybrids. The Journal of Heredity 88, 361-365.

Walton, R. A. & Hosey, G. R. 1984. Observations on social interactions in captive Père David’s deer (Elaphurus davidianus). Applied Animal Ethology 11, 211-215.

Wu, J.-y. 1991. The ungulates of northern China. Rangifer 14, 57-64.

Darren Naish About the Author: Darren Naish is a science writer, technical editor and palaeozoologist (affiliated with the University of Southampton, UK). He mostly works on Cretaceous dinosaurs and pterosaurs but has an avid interest in all things tetrapod. His publications can be downloaded at darrennaish.wordpress.com. He has been blogging at Tetrapod Zoology since 2006. Check out the Tet Zoo podcast at tetzoo.com! Follow on Twitter @TetZoo.

The views expressed are those of the author and are not necessarily those of Scientific American.





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  1. 1. Surroundx 9:09 am 10/11/2011

    Re. hybrid species, there was also the recent revelation that polar bears are a hybrid species. Very fascinating stuff!

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  2. 2. Mark Evans 10:31 am 10/11/2011

    I definitley remember the story of Père David’s deer being on Blue Peter. I’m guessing perhaps early 1980′s.

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  3. 3. Maija Karala 10:33 am 10/11/2011

    “Somewhat surprisingly, inbreeding depression does not (yet) seem severe in these animals.”

    Could it be that resistance to inbreeding depression is common in deer trough some strange genetic mechanism?

    The Finnish introduced population of white-tailed deer originated from four individuals imported from Minnesota in 1934. Apparently, they imported a few more individuals in 1948, but that’s it. Even if all the released deer survived to breed, there can’t have been more than ten of them. Today the country has a still-growing population of more than 30 000 individuals, with no signs of inbreeding problems.

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  4. 4. vdinets 11:33 am 10/11/2011

    Milu is now really easy to see in the wild – there is a nature reserve called Dafeng Milu, close enough to Nanjing and Shanghai to be visited on a weekend trip. Of course, the reserve doesn’t look like Yellowstone – it’s a small patch of forest and a tiny marsh surrounded on all sides by villages.

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  5. 5. victorg 12:07 pm 10/11/2011

    For (some) whiptail lizards, demonstration of hybrid origins of some “species” was demonstrated by experimentally “creating” them again from the parent species. Given a “Milu x Red deer hybrid” was recorded, is it possible that hybrids from stocks similar to Milu’s parent ones are known?

    Maybe there just isn’t an active hybridization fetish for deer like the one we have for big felines :)

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  6. 6. DMA12 1:07 pm 10/11/2011

    Nice banner at the top. By the way, I’m starting my own blog. It’s at http://www.devin-adler.blogspot.com. Spread the word.

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  7. 7. WillemvanderMerwe 1:38 pm 10/11/2011

    Hello Darren and thank you very much for this fascinating article! Here in South Africa I am lucky enough to have seen the Milu. Even when I was very young (five or six years old) I remember seeing it in the Pretoria Zoo! What struck me was its large splayed hoofs and its long weird face. We came home from the zoo and found it illustrated in the Colliers Encyclopedia. I have subsequently always made a point to go and see them whenever I visited the zoo. I wonder how many there are here in South Africa? I wonder how many there are in the world?

    By the way the Red Deer/Milu hybrid looks very interesting. It has a more ‘handsome’ red-deer like face, but the antlers are quite weird, being so long and hardly branching!

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  8. 8. John Harshman 2:05 pm 10/11/2011

    Breaking out of the tetrapod mold, remember that hybrid speciation has been accepted in plants for a long time. Botanists (at least in my experience) solve the tree problem by showing two branches leading to the hybrid species (or clade), one from each parent lineage. Makes perfect sense to me, though if you accumulate enough of it the tree gets messy looking.

    Most of those hybrid speciations are examples of allopolyploidy, in which each parent contributes exactly half the genome. In the case of mammals, we might grade into a situation in which one of the two “parent” lineages contributes only a small percentage of the genome, with speciation otherwise being of the ordinary allopatric sort. How much introgression do you need before you start talking about hybrid speciation?

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  9. 9. Max Blake 2:22 pm 10/11/2011

    According to Lever (2009) (referencing a variety of sources, inc. Baker 1990), Milu have escaped a number of times into the wild in Britain. One was seen near Aston Abbotts in Buckinghamshire around 1963-4, which probably came from Woburn. Apparently several from the Swindon herd were at large for a couple of years.

    A herd of 25-30 has been “frequently observed up to 16km from the estate”. The estate in question is at Ashton Wold near Peterborough. In 1977 two yearling males were reported in Monks Wood (13km away), and two stags were shot 14km away from the estate in Wooley. Then:

    “Young calves seen well away from the estate have almost certainly been born in the wild.”

    In Scotland, in the late 1940′s a group escaped from a zoo in Stirlingshire, one of which lived at Balmaha near Loch Lomond in 1952-3.

    Interesting stuff, I will try and dig through his references when I have time.

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  10. 10. victorg 4:16 pm 10/11/2011

    OT…

    @DMA12: Here’s what I’d post there if you didn’t require a ‘profile’: “Bookmarked and subscribed, blame your nice and knowledgeable comments at TetZoo :) ”. The option to post without association with an existing account would be nice (but might be more trouble than it’s worth).

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  11. 11. naishd 4:37 pm 10/11/2011

    Thanks for comments. With regard to comment 6: the current banner is, in my opinion, pretty lame – it’s very much provisional and was cropped in a hurry (you might be able to see that it’s just part of the ver 2 banner). It’s due to be replaced any time now, stay tuned…

    Darren

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  12. 12. Andrew O 5:36 pm 10/11/2011

    about the “weird” male milu in the photo right above the cladogram- does it’s head look [i]really[/i] asymmetrical to anyone else? I don’t just mean the antlers- [i]everyone[/i] has asymmetrical antlers, after all- but it looks like its skull is almost banana-shaped, with the rostrum curving to the right, and the right frontal bulging significantly more than the left.

    Could just be the camera angle, but it’d be fascinating if it isn’t. What caused the bent skull- trauma? some developmental abnormality? Is this just an aberrant individual, or does such cranial asymmetry pop up often amongst milu- or cervidae in general? Does it serve any adaptive purpose? What effect, if any, does it have on antler growth?

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  13. 13. Andrew O 5:42 pm 10/11/2011

    (btw, sorry for the stray html tags. I only just registered, and I didn’t realize they aren’t enabled. Is there any other system in place? or is formatting just disabled in general for comments?)

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  14. 14. naishd 6:15 pm 10/11/2011

    Hi Andrew – the lack of functionality here as goes html tags is a bit of a nagging problem. I’ve voiced my opinion behind the scenes – nothing else I can do. Anyway… yes, I think you’re right – that individual does have a bent skull. And this isn’t tremendously rare in deer – it’s called campylognathia or bent-nose syndrome. No idea what causes it but I assume it’s just a developmental anomaly. Anyone know any more?

    Darren

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  15. 15. Jerzy New 6:58 pm 10/11/2011

    Some quick comments…
    1. It is normal that inbred vertebrates don’t show any ill effects. Apparently, european badger and euro beaver are seriously lacking genetic diversity without ill effects.

    2. I heard that all Pere David’s deer in existence are in fact descended from 1,2 from Berlin Zoo. Apparently, there was additional inbreeding before and after Duke of Woburn work. I would be interested in confirming/refuting this.

    3. Hybrid origin: I think PDD result can be better explained by single genes being non-representsative. But in principle, doesn’t common intergeneric hybridization mean that: a) large mammals and birds are historically oversplit, and becoming more oversplit still, b) cladistics is wrong approach in principle, at least up to family level, and basing genera and species on monophyly is wrong approach?

    4. I also long wondered why PDD is always put in own genus, despite the genetic work placing it within Cervus and fertile hybrids. Perhaps historical latency.

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  16. 16. DMA12 9:47 pm 10/11/2011

    @victorg. Do you think I should switch to wordpress instead.

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  17. 17. David Marjanović 10:33 pm 10/11/2011

    cladograms are not generally meant to be evolutionary trees: rather, they’re
    schematic representations of branching sequences

    No. Cladograms are phylogenetic hypotheses produced and tested by a cladistic analysis.

    And yes, cladistic analysis cannot directly deal with hybrids. Possible hybrids can only be identified from cladograms by their occurring in polytomies.

    Most of those hybrid speciations are examples of allopolyploidy, in which each parent contributes exactly half the genome.

    Animals don’t do polyploidy well at all. It happens, but it occurs very rarely.

    btw, sorry for the stray html tags. I only just registered, and I didn’t realize they aren’t enabled.

    A few, such as <i>, are enabled. You just have to type them as HTML, with <pointy brackets> (“greater than” and “less than” signs), not as BBCode. This is not a forum.

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  18. 18. Dartian 4:19 am 10/12/2011

    Surroundx:
    polar bears are a hybrid species

    Not quite, at least not in the same sense that the milu is purported to be. The polar bear didn’t originate by interspecific hybridisation – it originated when some brown bears relatively recently split off from the main population and adapted to living in the Arctic. What the Edwards et al. (2011) paper (which I presume you’re referring to) suggests is just that there has since then been occasional interbreeding between representatives of the brown and the polar bear lineages.

    There has, however, been a bizarre-ish claim in the literature that the polar bear would indeed be of interspecific hybrid origin. In 1993, Zhang & Ryder published a paper in PNAS where they presented the results of an mtDNA comparison of arctoid carnivores. According to their results, the closest living relative of the polar bear was – the South American spectacled bear Tremarctos ornatus! The authors suggested that this supposed polar bear-spectacled bear clade split from the other extant bears 2 Mya.

    In 1994, Zhang & Ryder published the results of a new study, with an expanded data set. They failed to replicate their earlier results; this time their data recovered a brown bear-polar bear clade. As an explanation of their anomalous earlier result, Zhang & Ryder suggested that there might have been ancient hybridisation between tremarctine and ursine bears when the latter invaded North America in the early Pleistocene, and that the traces of this were still visible in the mitochondrial DNA of some individual polar bears. AFAIK, that was as close to a retraction* of their earlier result that the authors got. (Personally, I suspect that their samples in the 1993 study were contaminated.)

    * As is so often the case, the spectacular results are published in a high-profile journal, while a follow-up study with a correction/retraction is published in a lower-ranking journal – or not at all. (No offense intended to Mol. Phylogenet. Evol.; it is an excellent journal, but a paper there doesn’t quite have the same visibility as a paper in PNAS.)

    Maija:
    Could it be that resistance to inbreeding depression is common in deer trough some strange genetic mechanism?

    Your point about the introduced Finnish white-tailed deer Odocoileus virginianus population having descended from a tiny handful of individuals is a good one. I don’t know the answer to your question, but I rather think it’s too early to suspect that cervids in general would be somehow particularly resistant to deleterious effects of inbreeding. For hundreds (or even thousands) of years, people have been trying to introduce several species of cervids to various parts of the world. Some of these introduction attempts have failed, while others have succeeded. There may well be a pattern to this, but genetic (non)diversity of the founding population is surely only one of the variables that affects the outcome.

    Jerzy:
    doesn’t common intergeneric hybridization mean that: a) large mammals and birds are historically oversplit, and becoming more oversplit still, b) cladistics is wrong approach in principle, at least up to family level, and basing genera and species on monophyly is wrong approach?

    a) How do you define what is a “genus”?
    b) How do you define what is “family level”?

    You need to have good answers to those questions before you can continue with your line of reasoning.

    References:
    Edwards, C.J., et al. 2011. Ancient hybridization and an Irish origin for the modern polar bear matriline. Current Biology 21, 1251-1258.

    Zhang, Y.-P. & Ryder, O.A. 1993. Mitochondrial DNA sequence evolution in the Arctoidea. Proceedings of the National Academy of Sciences of the United States of America 90, 9557-9561.

    Zhang, Y.-P. & Ryder, O.A. 1994. Phylogenetic relationships of bears (the Ursidae) inferred from mitochondrial DNA sequences. Molecular Phylogenetics and Evolution 3, 351-359.

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  19. 19. farandfew 5:35 am 10/12/2011

    I would have thought that the Milu, a species which was maintained for a very long time in captivity as a small population, is exactly the kind of animal which you would expect not to show inbreeding depression. Deleterious alleles should have largely paired up and dropped out. Why it isn’t more ‘domesticated’ is perhaps a different question.

    btw, Robert Twigger’s odd half-novel about the Milu, ‘The Extinction Club’ has a bit about the Blue Peter episode on Pere David.

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  20. 20. Dartian 6:06 am 10/12/2011

    Oh, and Darren; you mentioned Dendroica in your post. That genus is no more.

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  21. 21. Jerzy New 7:54 pm 10/12/2011

    @Dartian
    True, cladistics is useless tool in lower-level taxonomy in general (because we cannot be sure at what point hybridization becomes impossible).

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  22. 22. Jerzy New 8:03 pm 10/12/2011

    BTW, I always thought that speciation in most cases takes place by whole populations diverging from each other. So “hybrid origin” as seen by “mtDNA grouping differently than nuclear DNA” would be a bit difficult – how a whole population of hybrids of male one species and female of another can appear in real life? I guess it is more an artifact of theories of phylogenetic trees and statistics in evolution.

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  23. 23. Dartian 4:44 am 10/13/2011

    Jerzy:
    I always thought that speciation in most cases takes place by whole populations diverging from each other

    The size of the (whole) founding population that initially branches off from the main population can be very small. In principle, just one pregnant female* may be enough to start a new population, which, if the conditions are favourable, may survive long enough to become specifically distinct from its parent species. And this new species, in turn, might be the starting point of a huge evolutionary radiation (cf. the discussion in the recent hoatzin thread).

    * To be really pedantic, even one single individual will be a ‘population’, if it happens to be the only one of its kind (either locally or globally).

    Link to this
  24. 24. naishd 5:26 am 10/13/2011

    I forgot to thank Max in particular for the info on escapee Milu in the UK (comment 9) – I don’t have Lever (2009) so this info was new to me. Wow, Milu calves being reportedly born in the wild! Thanks to others for comments too. And note that the new banner has gone live – more on that soon.

    Darren

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  25. 25. KarMannJRO 6:32 am 10/13/2011

    One last question just came to me. Is it pronounced like “me-loo”, “my-loo”, “milieu”, or some other way?

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  26. 26. puppygod 11:33 am 10/13/2011

    Approx. “me-loo”. You can listen to original pronunciation on the nciku dictionary: http://www.nciku.com/search/zh/detail/麋鹿/27217

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  27. 27. Jerzy New 4:28 pm 10/13/2011

    @Dartian
    In many (maybe most) cases, species is started by a whole population, that’s you have for example phenomena like incomplete lineage sorting.

    I agree, that eg. for land animals colonizing oceanic island, species sprouting from one or very few individuals is likely. But this is not only, or necessary most common, situation.

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  28. 28. victorg 4:41 pm 10/13/2011

    OT again…

    @DMA12 Adding the option to post a comment with name/URL or even anonymously would make it easier to post (as well as increase the chance of getting spam). It should be an option in Blogger, you can always restrict comments to registered people later on if want to.

    Link to this
  29. 29. Dartian 3:28 am 10/14/2011

    Jerzy:
    In many (maybe most) cases, species is started by a whole population

    But, as I pointed out (apparently not clearly enough) in comment #23, that “whole population” may be two individuals just as well as it may be two thousand individuals. (Of course, the larger the founding population is, the more likely it becomes that enough of its members leave enough surviving descendants – but that’s a different issue.)

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  30. 30. John Scanlon FCD 9:35 am 10/18/2011

    “cladistics is useless tool in lower-level taxonomy in general (because we cannot be sure at what point hybridization becomes impossible)” (Jerzy New)

    At what ‘point’ going up or down? Going down far enough, it’s not hybridization but chromosome fission and fusion, recombination between linkage groups, between genes, within genes; eventually it gets lost in the stochastic fuzz and cladistics becomes a poor approximation to maximum-likelihood.
    Going up, remember that interfertility is symplesiomorphy, but you can still always do cladistics on short enough bits of DNA (gene trees) and potentially recover all the topologies that contribute to ancestry of modern taxa, and their relative importance (see recent papers on the Neandertal/Denisovan stuff). Hybridization will be indicated if the topologies are different enough, unless they’re so different that we call it ‘lateral gene transfer’ (I’d say it’s really the same thing, so hybridization is never impossible). Mitochondria and Y chromosomes are the biggest non-recombining chunks (‘genes’) in mammals, but won’t get you the whole story if it’s really messy.
    Also, a large enough set of phenotypic characters can potentially be analysed for multiple component topologies in the same sort of way, though it’s hard because they don’t come in a definite sequence, and a lot of the apomorphies of both parents will get lost in the hybrid (I once tried this on paper with pythons).

    Those Milu antlers are quite variable, and I notice the formosanus is shown with a basal polytomy. Is the forked anterior tine a case of LBA between brow and bez? If you ever find an antler that anastomoses as well as branching, I think we can accept the hybrid-origin hypothesis…

    A few papers of interest:

    Carstens, B.C. & L.L. Knowles. 2007. Estimating Species
    Phylogeny from Gene-Tree Probabilities Despite Incomplete Lineage Sorting: An Example from Melanoplus Grasshoppers. Systematic Biology 56, 400-411. doi: 10.1080/10635150701405560

    Huson, D.H. & D. Bryant. 2006. Application of Phylogenetic Networks in Evolutionary Studies. Mol. Biol. Evol. 23, 254–267. doi:10.1093/molbev/msj030

    Legendre, P. & V. Makarenkov. 2002. Reconstruction of Biogeographic and Evolutionary Networks Using Reticulograms. Syst. Biol. 51, 199-216.

    Mallet, J. 2007. Hybrid speciation. Nature 446, 279-283. doi:10.1038/nature05706

    Reich, D. et al. 2011 Denisova Admixture and the First Modern Human Dispersals into Southeast Asia and Oceania.
    The American Journal of Human Genetics 89, 1-13. doi:10.1016/j.ajhg.2011.09.005

    Schwenk, K., N. Brede, & B. Streit. 2008. Introduction. Extent, processes and evolutionary impact of interspecific hybridization in animals. Phil. Trans. R. Soc. B 363, 2805–2811. doi:10.1098/rstb.2008.0055

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  31. 31. David Marjanović 5:33 pm 10/22/2011

    Mitochondria and Y chromosomes are the biggest non-recombining chunks (‘genes’) in mammals

    …and the Y chromosome does, AFAIK, recombine with the X one, it just happens very rarely.

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  32. 32. James Hudson 5:06 am 10/23/2011

    Surprisingly, I had never heard of the milu before this series of posts. Really interesting stuff. The thing that struck me most about the antlers was the bending near the tips. I guess you see some of that in our North American cervids (specifically I’m talking about north temperate species: Odocoileus virginianus, O. hemionus, Cervus canadensis, and Rangifer tarandus) but I don’t think I’ve ever seen one with that much curviness in the antlers. Combined with the lack of branching and the antlers certainly don’t look to me like an elk, mulie, or white-tail.

    Slightly off topic: is the elk or wapiti definitely now separated from the red deer and no longer Cervus elaphus? I took mammalogy just a year or two ago and I’m pretty sure we learned they were one species then.

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  33. 33. Brandi 8:50 pm 11/16/2011

    So happy to see this. I was looking up giraffe facts for work (education dept at a zoo) and not only found some great giraffe info, but also stumbled on this article with a photo of Pere Davids from my zoo! Love your antler collection. Thanks and bookmarked!

    Link to this

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