Why do museums have genetics labs?
The answer to that question depends to some extent on what you think when we say “genetics”. While generally museums don’t engage in the type of genetic engineering that lead to the cloning of Dolly the Sheep, we do use DNA extensively to complement our fundamental biodiversity research programs in taxonomy and systematics.
Taxonomy is the science of the discovery, description, classification and naming of species.
Systematics is an expansion of this work, classifying species according to their evolutionary relationships.
Species are traditionally described on the basis of their morphology, that is, their internal and external physical features e.g. their size, number of appendages, skeletal structures, colour patterns, growth forms, scale shape and so on.
There are, however, a number of problems inherent in using morphology to classify organisms:
- Morphology is influenced to some extent by the environment. Unrelated organisms can independently evolve very similar features as a result of having to adapt to living in similar environments. A classic example is the dorsal fin and torpedo-like body shape of ichthyosaurs (extinct marine reptiles), sharks (fish) and dolphins (mammals).
- Speciation is not always accompanied by morphological changes. Some groups are morphologically “austere”, that is, they lack distinguishing physical characters and in some groups morphology is highly conserved. These issues can lead to 2 or more species being classified as one because they are superficially indistinguishable resulting in what is known as “cryptic species.”
So how can DNA help? The variability in DNA sequences can provide greater resolution and allow us to identify species objectively. Furthermore, DNA is much less susceptible to environmental influences. By comparing DNA sequences from different organisms and measuring the number of changes (mutations) between them, it is possible to determine if species are closely or distantly related.
As a result genetic analyses have now become commonplace in scientific research conducted at museums. DNA does not and will never replace classical morphology-based taxonomic studies but works as a valuable complement to them.
Queensland Museum's Find out about... is proudly supported by the Thyne Reid Foundation and the Tim Fairfax Family Foundation.