In an BBC article describing a Royal Society paper on the rate of mutation in warm vs. cooler climates, the BBC made this statement:
DNA can mutate and change imperceptibly every time a cell divides and makes a copy of itself.
But when one of these mutations causes a change that is advantageous for the animal – for example, rendering it resistant to a particular disease – it is often “selected for”, or passed down to the next few generations of that same species.
Such changes, which create differences within a population but do not give rise to new species, are known as “microevolution”.
I suppose the BBC is into the Hopeful Monster theory or something.
Read it here, come back, and fight it out.
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Sounds like some anti-evolutionists sit on the editors’ board. Either that, or they’re making a faux-pas that will be eaten up by cdesign proponentsists. Sorta like the “Darwin Was Wrong” cover of New Scientist.
You have to be so careful to word everything so perfectly just to keep them from latching onto the least little fundamental misunderstanding on the part of a science writer. I don’t envy the average science writer’s job, having to walk the line between “readable” and “not totally fundamentally wrong”.
I take it they mean that the genes in different subsets of a population can change without immediately rendering members of one subset incapable of mating with members of another.
Errmm.. is that a big deal? Did you somehow read this to imply that such changes would never result in a new species be they pushed ever so far? If so, that might be a product of your cultural environment? Or else I’m missing something. Are you upset about the ‘passed down for a few generations part’?
Well, I’m personally waiting for them to go nuts and use it as a bludgeon, like the creationists did with that New Scientist cover. I dunno if that’s the point Greg was driving at, but it’s certainly my personal facepalm reaction.
Do they even understand how life works?
Do they mean cell division in egg cells which do not change since birth of a mammal? Or do they mean cell division in the other 99.9999999999999999999999999% of the cells that have nothing to do with reproduction?
Technically, speciation doesn’t occur until two populations are unable to have offspring with each other, though. Just because the evolutionary pressure of malaria has selected for sickle cell trait hasn’t yet made humans that carry hemoglobin S a separate species.
Technically, speciation doesn’t occur until two populations are unable to have offspring with each other, though. Just because the evolutionary pressure of malaria has selected for sickle cell trait hasn’t yet made humans that carry hemoglobin S a separate species. Or am I missing something?
If you read the article, you can’t help getting these two things out of it:
1) This article is not about speciation; but nonetheless
2) Speciation is different form micromution and has a different cause, that cause not being mentioned in the article (because of #1).
I couldn’t find the article itself. Has it been published yet?
I was interested to see if they controlled for population density – for instance looking at the mutation rate in high temperature low population number ecosystems (such as deserts).
I think it comes over even worse when I read the whole article. They seem to to be stating quite clearly that speciation does not happen through many small steps. Crazy. Pity no comments are all allowed.
Yeah, sorry, I haven’t read the actual paper itself, but I just don’t get the sense that the summary on the BBC is implying that mutation can’t cause speciation. I am clearly missing something. From my understanding of biology, the only difference between microevolution and speciation is whether or not individuals with the mutation can still interbreed with the wild-type. But it’s still the same mechanism for mutation: cosmic rays, transposons, errors by the DNA replication enzymes, etc. And I don’t think it’s a settled question as to whether or not macroevolution is always entirely due to the additive effects of microevolution, or whether it is possible for the genome to sometimes evolve in sudden jumps.
So, each mutation means a new species, now? That’s a new one (but not necessarily wrong).
There are as more definitions for “species” than there are zoologists, because each uses lots, and botanists get their own. Most don’t use the “able to produce viable offspring” ones any more; otherwise most of the feline, and canine, and ursine species in the world would have to merge. (Not that that would necessarily be a bad thing.)
A common practical definition lately is “don’t seem to mate enough for significant mixing to occur”. It’s important to be practical, because it’s fundamentally arbitrary. Nature doesn’t care for your species, it only has populations.
It’s entirely legitimate to be interested in evolutionary changes of magnitude smaller than that which distinguishes one species from another — whatever your working definition may be. So, shame on you Greg.
The entire tone of the article indicates that Gill understands what she’s talking about, which argues against your claim, and the context of that one comment indicates correctly that one mutation will not cause speciation, so no, you’re wrong. They’re not discussing speciation here per se, but the rate of mutation. There’s nothing wrong with the comment and it certainly doesn’t indicate what you’re trying to suggest it does.
A much more interesting topic for discussion from Gill’s article is this: if we have only a certain number of cell divisions within us before we die, and if these divisions are sped up in the tropics, shouldn’t this mean that tropical life-forms tend to live shorter lives than organisms which live at higher latitudes or elevations?
If it doesn’t, then what is it which preserves lifespans there? Do tropical organisms harbor a secret of longevity or are cell divisions actually not sped-up significantly enough to matter in this regard?
Sigmund, sorry, I don’t mean the original published paper, I mean the BBC article. I have not looked at the original paper in RSB yet.
What’s the problem? The BBC article is correct about microevolution.
As far as maroevolution is concerned, some biologists think that it’s just a lot of microevolution while others (I am one) disagree. See Macroevolution.
Larry,
The difference between ‘microevolution’ and ‘macroevolution’ is a difference in the observed pattern. Microevovlution is, by by definition, evolutionary change that happens within the morpho-time-space thing we agree to call a spcies. Macroevolutionary change is thought of as larger scale, though it need not necessarily be speciation.
Neither concept speaks to mechanism. A large part of the misunderstanding people have of evolution is confusing pattern and process especially in relation to ideas like micro vs. macro evolution.
The article is ‘wrong’ not because it has microevolution right. Obviously. It is strange because it implies that small changes do not add up to large changes. They can.
Larry, I think you are going to have a hard time finding a way to disagree with me on this (once you get the reading of the BBC piece correct, which is what we are talking about here) so I’ll help you: I believe that adaptations are real. That is off topic, but now you can firmly disagree with me … 🙂
… and sometimes small changes just noodle around indefinitely, like skin, eye, and hair color in H. sap. It doesn’t matter how much you fool around with the melanin, you’re not going to get a new species out of it.
Greg, I really think you owe some folks an apology. Much more obvious targets for your scorn are going sadly unscorned.
Nathan, you can’t possibly be remotely serious.
What I find interesting about this thread is how utterly vague almost everything everyone has said is. Would people start using nouns or something please?
I’m happy to provide some invective, if you’d like. You DID say to “fight it out.”
Macroevolution and microevolution are useless delineations between subset and superset of the exact same activity. It’s like differentiating between running across the room and running to the corner store, as being microrunning and macrorunning, and that just opens the doors for idiots to then claim that macrorunning can’t possibly exist because it contradicts their worldview. (Somehow. I can’t think of a way to include that in the metaphor.)
All there is, is evolution. Evolution takes place within the scope of a population of creatures. If that population is split up, or has to compete for resources, or whatnot, then a speciation “event” occurs and the population is subdivided. Even once subdivided, for a short distance in genetic drift, they can intermingle and keep the “species” together. But if they don’t, for whatever reason, then they speciate, fo’ realz.
Saying that this is equal to a crocodile having a crocoduck baby is just losing the plot entirely.
Greg says,
You are correct. There’s nothing much wrong with the BBC article or with the part you quoted above.
I can’t for the life of me figure out what you are objecting to. I assumed it might have something to do with the decoupling of microevolution and macroevolutionâ??a concept that I supportâ??but that doesn’t seem to be your problem this time.
I’m pretty agnostic on the decoupling because I think the concepts are really shorthands and gloss the actual real life complexity of the question they (the concepts, as it were) are trying to answer.
Who knows, we may simply be in agreement here!
Stephanie Z: Are you saying that you think you can get a new species out of fooling around with melanin? Or that Greg never, ever misses scorning whoever deserves it? Please be more specific.
What creationists might make out of a research program, or its name, is about the last thing I will ever worry about.
I’m sure there is a way to get a new species by screwing around with melanin. There must be examples. There are plenty of species where signaling is closely related to group membership, boundaries, and mating, and where the signaling is visual. There are probably examples among insects. It is remotely possible that there are examples among the forest guenons.
Nathan, what you can’t possibly be serious about is coming to the blog of a member of MnCSE and telling him he needs to be ashamed and apologize to people because he cares more about wording that creationists will use as a political tool than you do. You can’t really be that much of a skeevy troll. Can you?
SZ: At least I’m not here name-calling.
Victoria Gill is a hard-working BBC reporter helping to explain real science to real people, and does not deserve scorn. She does deserve an apology. Nothing in her article is scientifically objectionable. Crazies will cite anything without concern for facts; looking over your shoulder for what crazies might do is a way to become one yourself. I don’t, and I don’t expect Ms. Gill to. Minnesotans may have a problem, but their problem is not Ms. Gill.
No one can predict whether any particular variation might be a step on the road to a speciation. But it’s perfectly reasonable to look at a set of changes and note that they spread throughout a breeding population and did not contribute to speciation, because, in fact, no speciation occurred. Such changes are valid subjects for study, and deserve a name. Reporters are welcome to use the name correctly, as Ms. Gill did in this case.
Study of evolution started with accounting for speciation, but there’s no reason to confine it there. H. sap. has experienced a great deal of micro-evolution over the last N millennia, and the likelihood of its speciating seems more remote now than it’s ever been, no matter what happens to the melanin.
(If you don’t think I’m allowed to disagree with Greg here, how do you account for his invitation to “come back here and fight it out”? Surely that’s up to him to decide.)
Nathan, what you’re allowed to do here has no bearing on whether you’re being an ass about it.
This is about Victoria Gill??? I had no idea. See, you have to be less vague.
She’s brilliant, I love her writing. She does a great job.
The article in question implies by omission and a little more than omission, and quite by accident, that tiny mutations do not add up to macro evolution. I think that’s funny.
I’m also absolutely confident that Victoria Gill does not have such a simplistic view of evolution, and to the extent that this article is screwed up in this way I’m certain can be blamed entirely on the editors.
SZ: I’m not used to seeing quite so much name-calling welcomed around here. Evidently some people don’t feel obliged to live up to the standard of discourse the rest of us do. If I were Greg, I would take that as disrespect, but, again, that’s up to Greg to enforce.
It appears Greg’s objection to the article is a matter of an anonymous editor (or the author) mistakenly substituting exactly one instance of “which” in place of “that”. Any grammatical error may be a great crime, of course. I have even seen Greg misplace an apostrophe more than once, but I would not long pillory him for it.
SZ, you’re probably right. A misreading of “such” by the copyeditor, perhaps prompted by a misplaced comma by the author, could account for this mess. There’s no way to determine where the problem originated just by looking at this snippet, so Greg’s claim that it “can be blamed entirely on the editors” is untenable.
The theory of evolution is a rational theory that has considerable support from scientific experiments and observations. What disturbs me most is that many “self-proclaimed open minded people” seem to be very anxious to stop trying to find flaws with it. I propose that taking such a stance is equivalent to intellectual suicide.