The Australian aquascape
To anyone who has lived within Australia for a given period time, and likely many from across the globe, it is clear that water is a precious resource. Rainfall across much of the continent is patchy and variable, and the availability of water is a critical aspect in the distribution, survival and evolution of many Australian species. Expectedly, these aspects play an even bigger role for those taxonomic groups that heavily rely on the presence of water; freshwater-dependent taxa such as fish, amphibians or aquatic invertebrates show a keen evolutionary relationship with water across the landscape.
Understanding genetic determinants
You’ve probably been exposed to one news headline or another in the recent past (let’s say the last 5 years) that reads something like “SCIENTISTS DISCOVER GENES THAT CAUSE (X).” X, of course, varies massively based on the study itself (and sometimes the bastardisation of said study by media): it can include describing medical conditions such as cancer, autism or congenital diseases; behavioural traits, such as sexual preferences; or broad physical traits, such as the classic problem of the inheritability of height. Unsurprisingly, you may think that trying to find the genes responsible for some traits should be either a) super easy, or b) super hard, depending on your own philosophical preference or the trait in question. So how do these studies come about, anyway?
Many things in life are the product of their history, and nothing exemplifies this better than evolution. Given the often-gradual nature of evolution by natural selection, environmental stressors and factors operating on long-term scales (i.e. over thousands or millions of years) can have major impacts on evolutionary changes across the diversity of biota. While many of these are specific to the characteristics of the target organism (i.e. are related to adaptive traits), non-adaptive (neutral) traits are also critically important in driving the path of evolution.
The concept of a species
We’ve spent some time before discussing the nature of the term ‘species’ and what it means in reality. Of course, answers to questions in biology are always more complicated than we wish they might be, and despite the common nomenclature of the word ‘species’ the underlying definition is convoluted and variable.