ALCEINI
Moose / Elk
The Moose / Elk (Alces alces) is the largest species of deer and there is a long history of arguing whether there are one or two species: Alces alces The European elk from W of the Yelisei River and Alces americana the Moose from E of the Yenisei river and North America. Among most experts the consensus is that Moose should be treated as one species, but non-surprisingly G&G argue for the recognition of two species. Unfortunately I cannot access the study (Boeskorov 1999) which supplies the data for the split, so I will simply follow the description given by G&G
Skins
alces is described as having an evenly brownish overall color, with legs whitish. americana is said to have an overall color from light brown to black, with legs from light to dark brown or grey.
Skulls & Antlers
In the skull of alces the posterior end of the nasal branch of the premaxilla is spoonlike, whereas in americanca it is narrow and pointed, though in both populations the other type also exists in rare cases. Antlers of alces mostly have a single palm, whereas most americana have a double palm. Subspecies cameloides from Mongolia and N China has almost unpalmated antlers. Antler shaft averages 91.3 mm in alces and 120 mm in americana.
Additional data
G&G state that the body size index (body length as percentage of shoulder height) of alces is 80.8-84.5%, whereas this is 77.8-89.6% in americana. There also exists a difference in karyotype between alces (2n = 68) and americana (2n = 70). Boeskorov (2003) also mentions that different rutting calls and fauna of helminth worms have been described between alces and americana
Although there seem to be clear differences in karyotype, as well as differences in size, skull and antlers, the overall picture is not as clear. Genetic research (e.g. Hundertmark et al. 2002; Hundertmark & Bowyer 2004) has shown that until very recently, ~60.000 years, there was no difference between americana and alces. So all differences have originated very recently. Moose also only seem to have colonised America in the past 15.000 years. Lister et al. (2004) compared the shape of the premaxilla (part of skull) across the range of Alces alces and found that though the European type dominated west of the Yenisei River and the American type E of the Yelnsei River, there was a very broad zone, where both types commonly occured and only in the western and eastern extremes of the range did all individuals have the same premaxilla type. This indicates a broad hybrid zone.
Summarizing
Moose / Elk present an interesting case where we seem to have speciation in progress and this is a case where in an evolutionary species concept one would recognize two separate species, whereas under a biological species concept both taxa belong to the same species. I am not sure what to make of this and we cannot look into the far future to see how both taxa would develop. Unfortunately not much seems to be known of animals in the hybrid zone and it would be interesting to see whether animals with hybrid characteristics have lower reproductive success than others. Until more evidence becomes available it seems better to me to keep americana as a subspecies of Alces alces.
In addition to the question whether alces and americana constitute different species, there is also debate about the validity of the multiple subspecies described in N America. Bowyer et al. (2002) provide some evidence that gigas from Alaska is not only bigger because of a different diet, but that there is some genetic basis for this as well.
The following 8 subspecies are normally recognized, of which all but alces would belong to the putative species americana:
A.a. alces Europe, Russia W of Yenisei River
A.a. pfizenmayeri Siberia, E of Yenisei River
A.a. burturlini extreme E Russia (sometimes included in gigas)
A.a. cameloides E Mongolia, extreme N China, SE Russia
A.a. gigas Alaska
A.a. shirasi NW USA,
A.a. andersoni, most of W and C Canada and parts of N USA
A.a. americana E Canada and NE USA
A.a. alces
@alexkant , Mogilev Zoo, Belarus
@gentle lemur , Highland Wildlife Park, Kingussie, UK
A.a. gigas
@zoo_enthusiast , Alaska Wildlife Conservation Center, USA
@Pleistohorse , Alaska, USA
A.a. andersoni
@geomorph , Minnesota Zoo, Minneapolis, USA
A.a. shirasi
@savethelephant , Shiras Moose Rocky Mountain National Park, USA
A.a. americana
@Pleistohorse , Maine, USA
References
Bowyer et al. (2002): https://www.researchgate.net/profil...d_genetics/links/0deec522f8757ad798000000.pdf
Boeskorov (2003): http://natuurtijdschriften.nl/download?type=document&docid=523503
Hundertmark et al. (2002): Mitochondrial Phylogeography of Moose (Alces alces): Late Pleistocene Divergence and Population Expansion - ScienceDirect
Hundertmark & Bowyer (2004): https://www.researchgate.net/profil...ics-evolution-and-phylogeography-of-moose.pdf
Lister et al. (2004): https://www.researchgate.net/profil...graphical-variation-in-cranial-morphology.pdf
Moose / Elk
The Moose / Elk (Alces alces) is the largest species of deer and there is a long history of arguing whether there are one or two species: Alces alces The European elk from W of the Yelisei River and Alces americana the Moose from E of the Yenisei river and North America. Among most experts the consensus is that Moose should be treated as one species, but non-surprisingly G&G argue for the recognition of two species. Unfortunately I cannot access the study (Boeskorov 1999) which supplies the data for the split, so I will simply follow the description given by G&G
Skins
alces is described as having an evenly brownish overall color, with legs whitish. americana is said to have an overall color from light brown to black, with legs from light to dark brown or grey.
Skulls & Antlers
In the skull of alces the posterior end of the nasal branch of the premaxilla is spoonlike, whereas in americanca it is narrow and pointed, though in both populations the other type also exists in rare cases. Antlers of alces mostly have a single palm, whereas most americana have a double palm. Subspecies cameloides from Mongolia and N China has almost unpalmated antlers. Antler shaft averages 91.3 mm in alces and 120 mm in americana.
Additional data
G&G state that the body size index (body length as percentage of shoulder height) of alces is 80.8-84.5%, whereas this is 77.8-89.6% in americana. There also exists a difference in karyotype between alces (2n = 68) and americana (2n = 70). Boeskorov (2003) also mentions that different rutting calls and fauna of helminth worms have been described between alces and americana
Although there seem to be clear differences in karyotype, as well as differences in size, skull and antlers, the overall picture is not as clear. Genetic research (e.g. Hundertmark et al. 2002; Hundertmark & Bowyer 2004) has shown that until very recently, ~60.000 years, there was no difference between americana and alces. So all differences have originated very recently. Moose also only seem to have colonised America in the past 15.000 years. Lister et al. (2004) compared the shape of the premaxilla (part of skull) across the range of Alces alces and found that though the European type dominated west of the Yenisei River and the American type E of the Yelnsei River, there was a very broad zone, where both types commonly occured and only in the western and eastern extremes of the range did all individuals have the same premaxilla type. This indicates a broad hybrid zone.
Summarizing
Moose / Elk present an interesting case where we seem to have speciation in progress and this is a case where in an evolutionary species concept one would recognize two separate species, whereas under a biological species concept both taxa belong to the same species. I am not sure what to make of this and we cannot look into the far future to see how both taxa would develop. Unfortunately not much seems to be known of animals in the hybrid zone and it would be interesting to see whether animals with hybrid characteristics have lower reproductive success than others. Until more evidence becomes available it seems better to me to keep americana as a subspecies of Alces alces.
In addition to the question whether alces and americana constitute different species, there is also debate about the validity of the multiple subspecies described in N America. Bowyer et al. (2002) provide some evidence that gigas from Alaska is not only bigger because of a different diet, but that there is some genetic basis for this as well.
The following 8 subspecies are normally recognized, of which all but alces would belong to the putative species americana:
A.a. alces Europe, Russia W of Yenisei River
A.a. pfizenmayeri Siberia, E of Yenisei River
A.a. burturlini extreme E Russia (sometimes included in gigas)
A.a. cameloides E Mongolia, extreme N China, SE Russia
A.a. gigas Alaska
A.a. shirasi NW USA,
A.a. andersoni, most of W and C Canada and parts of N USA
A.a. americana E Canada and NE USA
A.a. alces
@alexkant , Mogilev Zoo, Belarus
@gentle lemur , Highland Wildlife Park, Kingussie, UK
A.a. gigas
@zoo_enthusiast , Alaska Wildlife Conservation Center, USA
@Pleistohorse , Alaska, USA
A.a. andersoni
@geomorph , Minnesota Zoo, Minneapolis, USA
A.a. shirasi
@savethelephant , Shiras Moose Rocky Mountain National Park, USA
A.a. americana
@Pleistohorse , Maine, USA
References
Bowyer et al. (2002): https://www.researchgate.net/profil...d_genetics/links/0deec522f8757ad798000000.pdf
Boeskorov (2003): http://natuurtijdschriften.nl/download?type=document&docid=523503
Hundertmark et al. (2002): Mitochondrial Phylogeography of Moose (Alces alces): Late Pleistocene Divergence and Population Expansion - ScienceDirect
Hundertmark & Bowyer (2004): https://www.researchgate.net/profil...ics-evolution-and-phylogeography-of-moose.pdf
Lister et al. (2004): https://www.researchgate.net/profil...graphical-variation-in-cranial-morphology.pdf
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