STARTING OFF BIG
Today we will attempt to address some of the larger issues in this
blog series, beginning the story with a review of the most supported theories
of how fauna came to disappear during the Quaternary.
We will do this in the context of three species. It is really important to
understand some of the main theories for faunal disappearance, in order to answer our questions. So, we will start by concentrating on two of these. Climate and people.
To do this, we will assess these ideas in the context of some larger mammals of
the late-Quaternary. The woolly mammoth,
the straight-tusked
elephant, and the European
cave lion.
Today’s Contenders
As the sort of ‘logo’ of the Ice Ages,
mammoth species are both
well-known and well studied (Stuart,
2005). Towards the end of the Pleistocene woolly mammoths (Mammuthus primigenius)
were still present in Europe, and are good indicators of megafaunal disappearance. As well as mammoths we
will discuss the European Cave Lion (Pantheraleo
spelaea), and the straight-tusked elephant (Palaeoloxodon
(Elephas) antiquus), both are fairly well documented during the late-Quaternary. All three species were residing in Europe during the Pleistocene and offer us an insight into the reason so many large animals
disappeared during a geologically short period of time. The largest and most recent transition in climate
occurred during the switch from the last cold phase to the present warm phase (Lister
and Stuart, 2008). At around 45-50,000 years ago modern
humans entered Europe (Hoffecker, 2009; Müller et al., 2011). For this
reason, it is important to understand the interaction between these animals and
the factors that may have caused their demise.
(left) Woolly mammoth calf (Maschenko et al., 2006 p.154). (centre) Straight-tusked Elephant (Diedrich, 2014 p. 274). (right) Cave Lion (Diedrich, 2011 p.210).
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The woolly mammoth: Mammuthus primigenius
The woolly mammoth was both widespread and in recent decades has been rigorously studied by scientists. As a cold adapted species,
they thrived in cool episodes when open grassland environments covered the
landscape. When the climate deteriorated it is thought that this species
survived in Siberia, whilst in
Europe its presence continued up until the late-glacial (below) (Stuart,
2005). During the most recent glacial-interglacial
cycle this animal became
extinct in Europe. The difference between this cycle, and those previous, was
the presence of humans as predators (Stuart et
al., 2004). It is likely that they played a role in mammoth
disappearance. For example, during a stadial (cool interval) that lasted between
around 34 and 24 thousand years ago the woolly mammoth occupied large areas of Europe, but
this extent reduced before the Last Glacial
Maximum (coldest point in
stadial) (Markova et
al., 2013). As a cold adapted species it would be expected that
this animal would not begin to decrease its population size during a
favorable climate. Humans were not around during previous cycles, and
mammoths survived these (Stuart,
2005). This could suggest an interplay between humans and
climate, contributing to mammoth decline.
Woolly mammoth distribution until
disappearance from fossil record.
(Stuart, 2005 p.172) |
The straight-tusked elephant: Palaeoloxodon
antiquus
The straight-tusked elephant had a very different ecology to the mammoth.
Their greatest range was during warmer episodes. They preferred forested areas, temperate regions, and are well recorded in the Mediterranean (Stuart,
2005). Their extinction in Europe was earlier than the Woolly mammoth, and the difference between these species,
ecologically, makes this a great comparison! There is much suggestion that this
animal disappeared from Europe at the onset of the most recent cold period with
the move towards grassland environments (Stuart,
2005). Very recently a study in Italy has provided evidence
that humans scavenged the remains of this species, in this case where the animal had become trapped, and the carcass was then
exploited by the local population (Santucci et
al., 2016). Though there
is evidence for scavenging, and some
evidence for hunting. Whether
this was sufficient enough to drive this species to extinction is
questionable.
The Cave Lion: Panthera spelaea
The European cave lion became extinct during the
late-Pleistocene. This disappearance is thought to have occurred at around 14,000
years ago. There are suggestions that this was due to a move towards
warmer temperatures, which resulted in a reduction in open habitat (Stuart and Lister, 2011). Though, there has been proof that
humans exploited these animals for their furs, as well as evidence of the hunting of these animals. It is difficult to know to what extent
this affected their survival, though, large hunting events have been recorded (Cueto et al., 2016). There are alternatives to this. For instance, the loss of
prey. Data gathered on cave lion diet may suggest that they had a preference for preying
on reindeer whose extinction is suggested to be at a similar time to that of
the cave lion (Bocherens et al., 2011). Meaning that their disappearance could be the product of prey decline, or more likely multiple factors.
In all...
Stuart (2005) makes an important point, and in fact I like this paper a lot (which you may notice if you look at the citations!). Many species survived glacial-interglacial cycles in Europe, but not the last one. So why? Today has been a brief and broad summary and discussion of the disappearance of just three of the large mammals still around in the late-Quaternary, but there are many many more!
In Summary,
?
There are still a lot of questions... & we will look at these in the coming weeks!
In the following days we will be addressing two topics! Firstly, with one of the more controversial theories of species extinction in the Quaternary, as well as beginning to look at how animals moved in and out of Europe with climate change, and if that was the only reason for dispersal (likely not)...
This has been compiled by articles i have researched. Any add-ons, article links, and suggestions for future topics would be really appreciated (especially if there is any current evidence/news)!
Cya soon!
Wonderful and refreshing to read about a complicated topic in a simplistic, easy-to-understand way. I look forward to reading more about the theories of species extinction and migration in the Quaternary. Many thanks.
ReplyDeleteThanks Dan, many more to go yet!
DeleteI find your blog very interesting. It is as Daniel said, refreshing not to be overcome by jargon.
ReplyDeleteI personally think that the demise of endangered species today, could well supply some of the answers to the past and would like to hear more about smaller animals.
Thank you!!
We will be discussing smaller animals at some pint yes!
Deletehttp://www.nhm.ac.uk/our-science/our-work/origins-evolution-and-futures/extinction-large-mammals-late-quaternary.html
ReplyDeleteMay be interesting to take a look
Lister has a lot of papers on this subject, great author! There are also a few attached to the page, thanks for the link!
DeleteAs someone who is interested in these kinds of issues but doesn't have a thorough enough background in the truly scientific side, I highly appreciate the public, easy to read and understandable approach that this article takes. The questions which are asked by this article tackle much larger current issues and I am incredibly excited to see how the next article develops these ideas further! Will there be even more variety of the mammals covered? I look forward to reading more!
ReplyDeleteThanks for the lovely comment Hannah! There will certainly be more variety, yes! Keep following!
Delete