Central
Australia:
Certain desert
regions of central Australia have the highest diversity of lizard species
in the world. I have been working on ecomorphological relationships of
desert lizards in the Northern Territory, where I have seen a high diversity
of lizard species. The five groups of lizards in this region are varanids,
skinks, agamids, geckos and pygopodids (see pictures below). I have been
working on the ecology, behavior and morphology of the agamid lizards in
this region. Agamids are a sister group to the iguanids. Thus, comparing
these two groups on different continents but similar habitats (deserts)
will allow me to test hypotheses concerning evolutionary patterns and convergence.
| 1. Ctenotus
schomburgkii (skink) |
| 2. Ctenophorus
nuchalis (agamid) |
| 3. Varanusgiganteus
(varanid) |
| 4. Nephurus
levis (gecko) |
| 5. Pygopus
nigriceps (pygopodid) |
| 6. Varanus
tristus (varanid) |
| 7. Rhynchoedura
ornata (gecko) |
|
As with the Mojave
Desert (USA), central Australian deserts have a wide range of habitats
which lizards can occupy, from mulga woodlands to rocky gibber plains.
One of the most common habitats are the open spinifex deserts, as found
at Uluru National Park (photo above). An agamid species found in this type
of habitat is Ctenophorus clayi (pictured above); this is a small
ground-dwelling species which can often be seen moving from one spinifex
to the next. Another common habitat type are the desert ranges, such as
those in Kings Canyon National Park (pictured below). The most common agamid
species found in such rocky outcrops is Ctenophorus caudicinctus
(see below); this is a medium sized lizard that is agile and can move very
quickly across the rocky surfaces.
This study will allow
me to compare similar habitats on each continent and determine if similar
morphological and behavioral specialisation has evolved independently in
iguanids and agamids. For example, by examining sand dunes in Australia
(see below) and North America (see Mojave desert)
I can determine if convergent evolution has occurred in the sand specialists
on each continent. Does Ctenophorus isolepis (pictured below)
and Uma scoparia (see Mojave desert)
have similar morphological and behavioral adaptations to living on loose
sand? I will be using a comparative approach that combines ecological,
behavioural, morphological and phylogenetic information that will generate
several types of data for biogeographic and historical analysis, as well
as necessary information to test hypotheses of the origins of these assemblages.
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