Here’s a recent xkcd strip called “Magic tree”, which has an evolutionary twist:
When you “mouse over” the strip, you see this:
In other words, artist Randall Munroe is giving a humorous example of “convergent evolution,” in which those trees that most closely resemble cellphone towers are those that leave their genes. This form of evolution would, over time, produce trees that resemble those towers. This example is bogus, of course, because a tree generation lasts a long time—longer than cellphone towers have been around. But if you want to read about real examples of convergent evolution, try the Wikipedia article or Eric Pianka’s nice essay at the University of Texas zoology website.
In WEIT I briefly discuss convergent evolution, giving the famous example of convergence between species of placental mammals and marsupials in Australia. I also give an example from plants: the strong resemblance between cacti in the New World and euphorbs in the old.
But there are also examples in which non-treelike plants have, similar to the example above, evolved to resemble trees. I’ll leave readers to hunt for those, but put your answers in the comments below.
h/t: Steve, John
ferns, groundsels, lilies (Joshua “trees”)
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Would that be the legumes? Most people think of peas and beans and the like as decidedly non-treelike, mostly climbing vines…but the mesquite, palo verde, carob, ironwood, and I’m sure many others are all legumes. (And, incidentally, some of my favorite trees….)
Also, if I remember right, palm trees are rather closely related to the grasses…but I might not be remembering that right….
b&
The books column continues to sit on top of the blog entry on most of my browsers. I can’t see the cartoon.
You mean the top of the web site entry, right? 😉
Just click the link to see the original.
…also, a request for clarification.
I would think that Randall’s example isn’t of convergent evolution but rather of mimicry — like a non-Monarch butterfly evolving to resemble a Monarch because the Monarchs taste bad and thus aren’t as prone to predation.
I’ve understood convergent evolution to be, for example, why sharks, tuna, and porpoises are all torpedo-shaped despite having radically different ancestry — including a radically different morphology not that long ago, evolutionarily speaking, in the case of porpoises.
…?
b&
My very first thought was “Batesian mimicry!”
(Actually, I have to confess, it wasn’t. My first thought was “Müllerian”, because I always get them mixed up. But what I meant by my very first thought was Batesian mimicry…)
Actually, it has been established that the Viceroy is also unpalatable, so the famous Monarch/Viceroy example is actually Mullerian, not Batesian:
Ritland & Brower 1991:
Nature 350, 497 – 498 (11 April 1991); doi:10.1038/350497a0
I swear, I’ll never get caught up in the first place, let alone have a prayer of staying caught up….
b&
Yes, I am surprised by Jerry’s description here! Checking Wikipedia it comes down on mimicry # convergent evolution, since the former is correlated (or causal) and the latter is supposed to be uncorrelated. (IIRC, and it is too late to check, I’m headed for bed.)
There were many with me that commented on Munroe’s blog that he had finally, after 1500+ comics, made a science mistake. Maybe I need to go back and link to Jerry’s version.
But first I want to know more about convergent evolution vs mimicry, what is the differences and what is the similarities. How is convergent evolution correlated between species that doesn’t even need to exist at the same time, except by the environment? Sounds like teleology is creeping in!?
I wondered about that, too. Is mimicry a subset of convergent evolution?
Yes it is, Jerry has said this more or less explicitly in a recent post.
Thanks
I thought this too. Would not this example just be evolution period? Convergent evolution would be that trees became cell tower like to adapt to similar situations so they looked just like cell towers even though they were not related to cell towers. So maybe they started to look like cell towers because they found it advantageous to have people climb them or something….
But not only are the trees growing to resemble cell towers, the towers are growing to resemble the trees. They are both evolving towards a similar form, thus convergent evolution.
My question too. Isn’t this mimicry?
Related question. In the stock examples, like the marsupials mentioned, the species that show convergent evolution are separated geographically. Aside from mimicry, are there examples which are not separated?
Speaking of cartoons, have you seen Ruben Bolling’s The Miracle of Consciousness?
http://www.dailykos.com/story/2015/09/03/1415546/-Cartoon-The-miracle-of-consciousness
(Maybe that will do for a link.)
Palms and bamboo. Some of the extinct lycopods would also count.
Bonsai trees! 😉
I don’t think a bonsai cell tower would be too useful …
Of course the trees are at risk if they run into Doc of Edward Abbey’s, The Monkey Wrench Gang.
I’m with Ben Goren on this one. Species converge on a particular form, because they are pushed by the same selective pressure. A living species which evolves to mimic an inanimate object is practicing camouflage, a form of mimicry. Think of a moth that looks like a drop of bird shit.
Flys used for fly fishing? There is a lot of thought that goes into them and how and when to use the right fly. On a long time scale could some fish learn to avoid human made flies and then pass on their genes so that no more fish ever fall for human made flies? Of course, we are clever, so I would think we should always have the ability to adapt and make flies that somehow fool some of the fish some of the time regardless.
In the cloud forests here in Ecuador, there are several unrelated plants that have evolved to resemble the native bamboo. An orchid ( Elleanthus sp.) and a fuchsia are two of the most dramatic. If I have time I’ll dig out my photos of them this week. I think plant mimicry of other plants is more common than people imagine.
But is your example mimicry or is it convergent evolution? Does the evolved form benefit from looking like bamboo specifically (i.e. mimicry), or is its appearance just a side-effect of an advantageous shape (convergent evolution).
(As I understand it, I’m not a biologist)
cr
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Is there a list of adaptations that have been human or human culture driven? Obvious dogs, cats, etc., that we have bred have changed because of us, but how many claims for human driven adaptations are there? What are our guesses for the future of such?
Do we think crows, squirrels, or gulls (or others) have had genetically altered behavioral or morphological changes due to living close to humans?
Do antibiotic microbes count?
Any thoughts? I know there have been posts here in the past on different of these topics.
Stephen Palumbi’s book, The Evolution Explosion: How Humans Cause Rapid Evolutionary Change, is all about that.
More pointedly, is there a case of human created mimicry out there?
Or more simply, has any animal adapted lighter skin/fur to blend in with concrete, or some other kind of minimal adaptation due to a human created environment?
What about the light colored moths in England that became dark to blend in with trees darkened by coal dust? (If I’m remembering this right.)
I haven’t looked up the details, but I remember that there are some varieties of the wild corn relative, teosinte, that have evolved to look like corn – farmers in Mexico think they are corn and don’t weed them out of the cornfields.
Off topic, sort of. In Southern California, in a desert-like area, I once saw a cell tower disguised as an evergreen tree in a terrain with no such trees. Perhaps, it would have been more appropriate to disguise them as exceedingly tall Joshua Trees, or other cacti.
Sounds like the tower wasn’t doing a very got job at not being seen.
b&