The 'evolution' of language

This story, on today's BBC News, rather surprised me: **LINK**

http://www.bbc.co.uk/news/science-environment-42103058

The headline is "Galapagos finches caught in act of becoming new species" ... But it would perhaps be more true to say "Researchers caught in the act of re-defining terminology, to suit their own agenda"

MichaelG.

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[quote]

In the past, it was thought that two different species must be unable to produce fertile offspring in order to be defined as such. But in more recent years, it has been established that many birds and other animals that we consider to be unique species are in fact able to interbreed with others to produce fertile young.

"We tend not to argue about what defines a species anymore, because that doesn't get you anywhere," said Prof Butlin. What he says is more interesting is understanding the role that hybridisation can have in the process of creating new species, which is why this observation of Galapagos finches is so important.

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Well, you write as if that were a disreputable thing, but in practice language, and especially nomenclature, does have to evolve to match empirical findings.

There has long been discussion of the part of Neanderthal DNA in current human genetics, so the interbreeding of what might at one time have been considered discrete species should come as no surprise. The fact seems to be that the paleontological record of species existing in former times consists of snapshots, mostly rare and dispersed, of a process that's really more-or-less continuous but only patchily recorded in fossils.

Life moves from one era to another as fluidly as clouds across the sky. There really is no box to think outside or inside of.

Edited By Mick B1 on 24/11/2017 08:18:16

The poor professor is rather clumsily expressing something that is not 'new' at all.

In the early 80s I was taught that 'species' is a human concept we use to classify living things into useful, homogenous groups, and that as far as nature is concerned it is wholly artificial.

The 'interbreeding' definition was a convenience that has little meaning if applied strictly. To defend its use as well as genetic barriers between species (i.e. they simply cannot interbreed - goats and giraffes) one must resort to brining in other rules such as 'behavioural barriers', 'geographical barriers' and 'well in practice they don't interbreed very often'.

Of course this was more plainly obvious to botanists at the time, but it's plainly nonsense if any thought is given to the methods by which evolution takes place.

Ultimately 'species' is simply a label to help us distinguish individuals from two similar but distinct populations (with little or no gene flow between them) of living creatures when placed side-by side.

The distinction 'sub-species' is even more tenuous and might apply when there is 'limited gene flow between the populations'.

If sepcies wasn't so damn useful for classifying things it would have been abandoned as a concept decades ago. To understand evolution and genetics it is far more useful to think in terms of populations (of individuals that interbreed within themselves and may have different levels of genetic exchange with other populations) and clades (of individuals with a common ancestor). Even these concepts are stained by the realisation that DNA can make dramatic leaps between hugely distinct populations.

Neil

Edited By Neil Wyatt on 24/11/2017 08:41:14

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I beg to differ, Neil

[ in my opinion ] The 'interbreeding' definition is [was] a very explicit one

and the distinction 'sub-species' is more appropriate for the case in point.

MichaelG.

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... I wonder what Charles Darwin would make of it.

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Edit: useful discussion here:

 http://www.ucl.ac.uk/taxome/jim/Mim/darwin_on_spp.html

Edited By Michael Gilligan on 24/11/2017 09:21:27

The interbreeding definition may have been both explicit and simple, but unfortunately it is not definitive. The lesser black-backed gull cannot interbreed with the herring gull. Each can however interbreed with neighbouring species, which can in turn interbreed with another, eventually forming a ring of seven interbreeding species. Therefore the classical definition that you are attempting to justify says that all of those species are the same as each can interbreed with another, whilst at the same time says that two of them are not the same.

Brian G

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I take your point, Mick ... but yes, I do think it's a disreputable thing to conveniently adjust definitions.

The reason that I mentioned it on this forum is that it brought to mind the 'evolved' usage of terms like

"precision", "inspected" and "individual test certificate"

... all of which now apparently mean less than they did; and are the subject of much discussion here.

MichaelG.

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Brian,

Does that not simply mean that there are seven sub-species ?

MichaelG.

All very interesting! Was it not the study of Galapagos Finches that started all this? However, more to the point, it is the position on the autistic spectrum of the human male, in counting, collecting and classifying items into groups, (he said carefully, avoiding any mention of any hobby whatsoever) from the backrooms of the Natural History museum to the collectors of ephemera.....

"Male pattern behaviour"

Geoff

I don't think those terms could ever have an absolute meaning.

'Precision' is always highly relative to the subject under discussion, and both the latter two terms don't state exactly what features have been inspected or tested, or whether these match the recipient's focus of interest.

Of course there are existing standards, but even if these are stated it's often too irksome to check against specific requirements, particularly in what's for most of us a recreational activity. No aeroplanes are going to fall out of the sky if my lathe's spindle nose has 0,01mm more TIR runout than is stated in its Individual Test Certificate - though in point of fact my belief is that it has less.

Personally I would agree with that, but by the most popular definition (the impossibility of interbreeding or the sterility of hybrid offspring), two of them are different species. To a layman such as myself this is confusing.

Should "species" just be maintained as a convenience as rightly or wrongly it forms part of the traditional naming of things in the same way as we still use conventional current in electrical circuits? Alternatively, does the combination of genetics and morphology require the terms "species" and "sub-species" to be retired or reinterpreted in the same way as quantum mechanics did for "wave" and "particle"?

Brian G

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Mick,

Please forgive the severe edit ^^^ but I think that line nicely supports my statement.

... it is indeed "often too irksome" for suppliers to the hobbyist market to actually "check against specific requirements" ... much easier for them to just soften the definition of the words a little.

MichaelG.

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A very good question, Brian ... and the answer is beyond me !

[but, unless and until the terms are retired, and reinterpreted, I shall remain reasonably content with the old definitions]

MichaelG.

Maybe a better definition to adopt when describing species as separate would be 2 genomes that are diverging.

Inability to interbreed or the production of sterile offspring would indicate that some considerable divergence has occured. Speciation (divergence) has to involve some degree of isolation of populations (gene pools) wether by geography, food supply or other factors. If you take the example of the removal of a land bridge between two populations in the case of sea level rise in a post glacial period. Suddenly the genomic mixing has ceased between the two populations and so they can diverge but clearly initially at least they are the same animals and would remain very closely related for some generations to come. Where and how you define the two as separate species rather than separate populations is open to question. The important thing as far as evolutionary biology is concerned is the divergence.

regards Martin

If a species is the lowest taxonomic rank, who sneaked in the concept of a 'sub-species'? (Terminology makes my head hurt!)

Quite often words change meaning usefully. A youngster might say that's random, meaning good. It's also common for words to change stupidly and unhelpfully. I'm confident that 'random' meaning 'good' is gormless, but often have trouble telling the difference between improved new usage and sloppy new usage. Policing language doesn't work well. Despite the efforts of the French Academy to come up with an acceptable native alternative, 'le car park' has caught on. Less picky English benefits hugely by nicking other people's words: for example restaurant and cafe improve on 'eating house'.

My pet hate is the gobbledygook written by social scientists. They've created an academic style using terminology in imitation of hard-science, mathematics and engineering. Unfortunately most of the borrowed technical words lose their original precision in the process. I think the result is turgid obfuscation. Even worse to me the style screams 'fake', probably not what the authors intended!

Dave

Edit: Can't spell (or type)

Edited By SillyOldDuffer on 24/11/2017 11:22:46

Edited By SillyOldDuffer on 24/11/2017 11:23:44

Is that post-modern irony?

And then there is "hardened bed ways", a sub-species of cheddar cheese.

That's an easy target, but not fair in all cases. There's some good social science work been done - it's just filtering it from the noise...

Perhaps our language is just getting more sophisticated?

I will leave it up to others to decide which of the available meanings to attribute to that statement

Brian G

Sorry about that Mick! My bad. I meant to criticise the style and misuse of terms rather than the underlying content or purpose. Nothing wrong with Social Science.

I'm an engineer hoist by his own petard - AGAIN!

Dave

Edited By SillyOldDuffer on 24/11/2017 12:55:21

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Dave,

[ my hypothesis ] : Given a rigid [and as Neil says, artificial] definition of 'Species' ... it seems inevitable that there will be some 'rule breakers'.

'Sub-Species' is therefore a convenient catch-all for those that "Would be a new Species, if it wasn't for the fact that [insert the appropriate awkward observation]."

MichaelG.