The Daily Bucket is a regular feature of the Backyard Science group. It is a place to note any observations you have made of the world around you. Insects, weather, fish, climate, birds and/or flowers. All are worthy additions to the bucket. Please let us know what is going on around you in a comment. Include, as close as is comfortable for you, where you are located.
Cold (for April) and damp in Tallahassee today. I don't have much new to report but thought I would post a bucket as none seem to be waiting in the wings. I did see one of the fledgling eagles this morning and right before dawn a pair of Great Horned Owls were perched on the snag across the street. I don't think I have seen two together before in our neighborhood. I don't know when they breed here - will have to look that up.
A short while back Milly Watt gave up a very nice bucket about the names of organisms and the names of the people who name them.
I thought I'd follow up with a bit more information on names and why they change. I don't have a lot of time to write today so I'll spread it out over several diaries.
The main purpose of having names is communication. It is very difficult to talk about anything without names. An important related point is that accurate communication requires agreement about names.
The very nature of spoken language immediately causes a problem here. Language that is in use all the time evolves. Words fall out of use, new words are created, and most commonly, words take on new meanings. The word 'gay' is a particularly dramatic example of this. At least in North America, I would guess that close to 100% of its use now is as an adjective or noun meaning homosexual completely supplanting the older meaning of the word.
Plants and animals often have different colloquial names in different regions. We bucketeers recently encountered this with the name 'blue bill'. This is a commonly used name for Scaup in some areas. Others of us had never heard this name before.
The system of scientific nomenclature devised by Linnaeus in the 1700s was designed to accomplish two functions. One was to incorporate all organisms into a single classification scheme. One of Darwin's great insights, several decades later, was that this classification scheme reflected evolutionary history. So one aspect of Linnean classification is that it should ideally reflect evolutionary relationships. I'll touch on this briefly here and can expand on it more in a later diary if there is interest.
The other function is to establish a single correct name for every species. That way there can be no doubt about what is meant if the correct name is used. When a new species is named a formal description is published and a specific specimen or set of specimens in a museum collection are designated as the 'type'. This way if there is any later confusion the specimens can be re-examined.
Precedence - One of the most common problems with this system is that many species have been described more than once. Particularly during the 18th and 19th centuries workers in museums would be receiving material shipped to them from collectors around the world. The same species could easily be described as 'new' half a dozen times at different museums.
When multiple names have been published the rule is that the earliest published name has precedence. Experts on different groups often spend years going through museum collections and revising classification to make it consistent. It can turn out that commonly used names are not the oldest. The most famous case of this is the name Brontosaurus and its 'replacement' Apatosaurus. Both names were coined by the same scientist for two different sets of fossils. Later workers proposed that the two fossils represented two very similar species in the same genus. As Apatosaurus was described two years before Brontosaurus the name had precedence and is the official name.
Classification Another common reason for changes in name is a change in classification. The general trend has been to make finer distinctions among groups. In other words the tendency has been to split things up rather than group them together. For example many North American reptiles and amphibians were once parts of genera (plural of genus) that occurred over large parts of the world. Examples include Bufo (toads), Rana ('true' frogs), Hyla (tree frogs), Natrix (water snakes), Elaphe (rat snakes), and Trionyx (soft shell turtles). In most cases (soft shell turtles are an exception) these animals had a fairly generalized body form for their group and a large number of species with that form were thrown into very large genera. More detailed studies have broken each of these genera down into multiple genera. In most cases the species from Europe were the first ones named and so they 'get' to keep the original genus name. So, for example, North American water snakes are now in the genus Nerodia while Natrix is only used for old world snakes.