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Seriously Folks, At Least Try To Get Evolution Right

Quite what we should expect from an environment correspondent trying to do actual science I’m not sure but we could hope for better than this at least:

Foxgloves brought to the Americas 200 years ago have evolved to be bigger to allow pollination by hummingbirds, researchers have found, as a new study concludes flowers can rapidly change shape to adapt to their environment.

No, this is entirely the wrong way around. Evolution isn’t something that is done – by plant or animal – it’s something that happens to a life form. The whole subject just doesn’t make sense if we don;t get this the right way around.

Scientists compared the size of foxglove flowers brought to Colombia and Costa Rica with those found in their native environment of southern England and concluded that the cone-shaped flowers were up to a quarter larger in the south and central American countries.

That’s fine.

In the UK they are typically pollinated by bees but in both American countries this role is carried out by hummingbirds, which are better at pollinating longer flowers, said the study published in the British Ecological Society’s Journal of Ecology.

So is that. But this is that wrong way around:

Thought to have escaped from the gardens of English engineers, who brought them from home in the 19th century, the flowers have adapted to their new surroundings in just 85 generations, an unusually rapid evolution.

The flowers – the plants – haven’t done anything. They’ve certainly not adapted. Further, they’ve not changed in order to do anything.

Here’s how it does work. In any generation or reproduction there is variation. Flowers, randomly because of mutation, more directly because of differences in food stocks perhaps, will be of different sizes spread across that new generation.

As is also true of near every generation of everything only some will go on to reproduce the next generation. Which, or who, depends on all sorts of things, near random factors – who got eaten by a llama perhaps, and who didn’t – and rather less random things like the absence of bees and the presence of hummingbirds in the new location.

In the entire absence of bees and the only method of pollination being the hummingbirds it will be the larger flowers that get pollinated. So, to the extent that larger flowers are genetically determined – and not by that presence or absence of a nice bit of food of phosphorous or summat – the next generation will have larger flowers.

Not because the flowers have adapted. Not because they have evolved. But because the small flowered foxgloves are all dead and dead childless, while the long flowered ones are admiring their grandchildren from the heavenly clouds.

The same thing in reverse would happen if we took normally hummingbird pollinated flowers and grew them in England where only bees would do that job. Flower sizes would shrink over the generations.

Plants and animals do not adapt, they do not evolve in order to do something. Evolution is something that happens to them. That survival of the fittest thing is the environment surrounding selecting among those who best fit that environment. By acting upon the normal random variation in the population, plus any newly arisen mutations, to promote, or hinder, certain types or variations breeding successfully or not.

To talk of “plants evolving to” is to make the Watchmaker mistake. Don’t do it.

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The Mole
The Mole
1 month ago

It amazes and frustrates me how common this mistake is. Though if I wanted to be really picky what you have described isn’t even evolution at all, it is merely adaption of species. The key difference being whether its just an existing trait (size) becoming dominate through existing less useful gene variants not being inherited, compared to evolution which is a mutation of the DNA to spontaneously produce a new gene variant (which then turns out to be useful and becomes dominant). I’ve not read the research, but I wouldn’t be surprise in the case of these foxgloves if it… Read more »

John B
John B
1 month ago
Reply to  The Mole

‘… whether its just an existing trait (size) becoming dominate through existing less useful gene variants not being inherited, ‘

That’s evolution.

The Mole
The Mole
1 month ago
Reply to  John B

No there is difference between natural selection and evolution. The classic example being rabbits. They may have gene combinations which make them either brown or white. If you started off with an even distribution of the genes then a) in the artic you’d expect the white rabbits to more likely survive and birth rabbits that are more likely to be white. b) in woodland you’d expect the brown rabbits to more likely survive and birth rabbits that are more likely to be brown. After enough generations you’d get two distinct rabbit populations that are generally specialized in one or other… Read more »

Snarkys
Snarkys
1 month ago

To be precise, natural deselection in action

Esteban
Esteban
1 month ago

It’s a bit like Adam Smith’s invisible hand, the effects often do seem planned. So much so that it’s quite common to see veteran science writers use terms that impute design, such as “the owl’s feathers are designed to be quieter than other raptors”. Quite easy mistake to make.

John B
John B
1 month ago

As Darwin put it, organisms that acquire characteristics through gene mutation which make them best suited for survival in their particular environment, will be more successful at reproducing. Aka natural selection.

Last edited 1 month ago by John B
The Mole
The Mole
1 month ago
Reply to  John B

Where did Darwin put that? He did put that organisms may happen to have characteristics through gene selection which make them best suited for survival in their particular environment, will be more successful at reproducing. Aka natural selection picking the best cards from the gene pool and carrying them over to the next generation. The key difference is that natural selection is all about taking the existing deck and reshuffling it and potentially removing some cards (total genetic variants stays the same or decreases). Evolution is when new cards are spontaneously added to the deck hopefully with beneficial advantages (mutations… Read more »

Reed
Reed
1 month ago
Reply to  The Mole

Where did Darwin say that?

TD
TD
1 month ago

To throw in some extra complexities, there are bees in Central and South America as they too were introduced by European settlers (though the Africanization of bees in Latin America may be a bit of an issue). Some American Indians called them English flies. I would guess that a bee could handle the longer foxglove just fine and also that a hummingbird could sip from a shorter one. Tim’s overall point is true, but are we sure about the specifics of this case?

The Mole
The Mole
1 month ago
Reply to  TD

I’m not, the simplest explanation is that growing conditions are better. Clearly the smaller flowers can also be pollinated by the native wildlife as otherwise the first few generations would just have died out. The other explanation is that the original flowers already varied greatly enough to be large, and natural selection has meant only the large ones survived. The fact that they successfully escaped in multiple places to be widely spread would imply that a large proportion of the escaped flowers survived multiple generations – if only 1 in 1000 flowers are ‘strong’ enough to spread then they are… Read more »

Last edited 1 month ago by The Mole
Nessimmersion
Nessimmersion
1 month ago

But But, what about the giant killer bees spreading up to the USA from the south.
Where do they come into the equation, if there are indeed no bees ( I find the contention that insects don’t pollinate in South and Central America rather challenging)

Spike
Spike
1 month ago

I don’t mind “plants adapted” (plant as the subject of the sentence). We all understand that an individual plant took no action and made no change. My red line is if an author anthropomorphizes and writes about what a flower or the crop “opted for.”

Bongo
Bongo
29 days ago

“who brought them from home in the 19th century”
The researchers presumably don’t have the 19th century British gardens to compare their foxgloves against any more. Maybe the engineers took the seeds from their best and tallest ones over.
There are rather a lot of varieties now. Dwarfs, and some that do ok in poor soils like railway embankments.

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