The Top 5 Most Irritating Terms In Evolution Reporting

| 28 Comments


The first one, “Survival of the Fittest” is the one that is most annoying to me. Why? Because it is often used as a synonym for evolution, but evolution is about so much more!


1. The fittest are not the only ones who survive.

Y’know who survives? The individuals that are sufficient. Sure, some individuals might be more fit than others, and they may have more offspring than others, but many individuals survive (and reproduce) who are certainly not the fittest. And some, who are arguably the fittest, may not survive to reproduce, just due to chance. 


2. The term is not specific about the difference between individuals and populations

While the fittest individuals may be more likely to survive to reproduce, they are not, themselves, evolving. New mutations occur in individuals, and individuals are subject to their environment. Yes, selection acts on individuals, but evolution occurs on populations. This point, that populations evolve, not individuals is crucial, and also wildly interesting because things as simple as the size and structure of populations can affect the efficiency of natural selection. For example, natural selection is more efficient in large populations. Alternatively, deleterious mutations are more likely to drift to high frequency in small populations. So, the fitness of individuals is related to the overall population of which they are a member.


3. Evolution isn’t all (or likely even primarily) about survival of the fittest

Survival of the fittest is often used to refer specifically to positive selection acting to favor the reproductive success of individuals with higher fitness in their given environment. This term gives the implication that nearly all of evolution is selection acting on mutations. with a beneficial effect Yes, this happens. But, there are other forces at work; two very important ones are:


1. purifying selection, which acts to remove harmful mutations from the population. An extreme example: if a mutation occurs that makes it impossible for all sperm to swim, that mutation will be eliminated from the population because the affected individual will not produce offspring.

2. (nearly) neutral evolution, whereby mutations with (little or) no effect on the fitness of the individual may drift to high frequency by chance, or because they are linked to mutations with an effect. For example, there are hundreds of thousands of repetitive elements that invasively insert themselves throughout our genome, and generally have no observable effect on fitness, but  continue to accumulate and even become fixed, simply because they do not significantly adversely affect  fitness. 



Whenever I hear “Survival of the Fittest”, I am reminded of this quotation:


Think of how stupid the average person is, and realize half of them are stupider than that.


- George Carlin

28 Comments

Well then how about “survival of the most adequate”? :)

Or more seriously, “differential reproductive success”.

An extreme example: if a mutation occurs that makes it impossible for all sperm to swim, that mutation will be eliminated from the population because the affected individual will not produce offspring.

Unless the individual is female, in which case its daughters might (or might not) manage to produce more offspring. (Unless you meant a mutation that caused the female to prevent sperm from getting to the destination, in which case make that male and sons instead.)

Yes, if the mutation occurs in females, it can get propagated, and perhaps even reach high frequency before it is selected against in males, or the species goes extinct. This is a great example of why, “survival of the fittest” is so confusing. Even the fittest female might make terribly unfit sons.

How about a “bit more fit than the rest”

It would be great to come up with a list of alternative phases for journalists to use. They need to be correct, concise, and catchy.

M. Wilson Sayres said:

It would be great to come up with a list of alternative phases for journalists to use. They need to be correct, concise, and catchy.

Save your breadth. Journalists are basically scientifically illiterates.

They need to be correct, concise, and catchy.

All three of those in one phrase? I don’t see how.

I agree that the first four terms are annoying, but so is this -

This is because it isn’t really the survival of the fittest organism that drives evolution. It’s the death of the least fit organism.

It’s not necessarily death or survival of individuals at all. It’s reproductive rate. A trait that confers longevity at the expense of relatively low reproductive rate may be selected against - individuals with the trait will individually live long lives, but there will gradually be less of them, relative to individuals without the trait. A trait that lowers life expectancy but increases reproductive success may be selected for. Individuals may die young but leave a lot of offspring that survive just long enough to leave a lot more offspring.

Humans just can’t seem to get their brains around the fact that, although selection acts on individuals, it is populations that evolve.

A terse but accurate definition of evolution is “change in frequency of alleles within a population”.

Earthly life evolves in an environment where resources are scarce, but that isn’t necessary for evolution. If there are 50% blue unicorns and 50% pink unicorns on a magical planet where resources can never run out, and they all love each other, and all babies born live long happy lives, but the blue unicorns have babies 0.1% more often than the pink ones (and they don’t interbreed), then there will be evolution. Alleles associated with the blue color will increase in frequency. As the happy magical population of unicorns trends toward infinity, the proportion of blue unicorns will trend toward (although never quite reach) 100%.

Premature death, predation, parasitism, and all that stuff happens on earth, because it is inevitable here, but evolution is the change in frequency of alleles in a population.

I’ve always liked “live long enough to get laid”.

And

fnxtr said:

I’ve always liked “live long enough to get laid”.

And successfully live with the consequences.…

fnxtr said:

I’ve always liked “live long enough to get laid”.

And it’s only that complicated for sexual diploids and polyploids like us.

“Live long enough to divide” is good enough for the vast majority of the biosphere.

harold said:

fnxtr said:

I’ve always liked “live long enough to get laid”.

And it’s only that complicated for sexual diploids and polyploids like us.

“Live long enough to divide” is good enough for the vast majority of the biosphere.

“Divide and conquer;” that’s why they are in the majority.

Journalists are basically scientifically illiterates.

Not Carl Zimmer

harold said:

Humans just can’t seem to get their brains around the fact that, although selection acts on individuals, it is populations that evolve.

I think that phrase (or some variation) ought to be “it”: “Populations evolve, not individuals.”

The phrase is clear, concise, catchy, and most importantly, it’s true. It avoids, contradicts, and explains the misconceptions of both, “If people evolved from monkeys, why are there still monkeys”, and the ever popular question of which monkey gave birth to the first human (or rephrased a different way, “How long did the first human male have to wait for the first human female to be born?”) It also differentiates Evolution from Lamarckism, which Marilyn was recently having trouble with in these pages.

Despite having an intellectual understanding of the mechanics of evolution (with mutations, and DNA, and changes, and selection happening over deep time), it wasn’t until relatively recently (perhaps since Dover?) that the importance of “populations evolve” struck home with a real “Aha!” moment. (Or was that a, “Well, duh!” moment?)

The key to that understanding (and the misunderstandings) is that “mutations” happen to individuals. So, naturally, it must be individuals that change from one generation to the next. Right? So, it would seem that this same mutation must occur in each individual separately in order for the mutation to become “fixed” in the population, and thus a new species to be born.

But it isn’t like that at all. Even though mutations happen to individuals, it’s the population that is constantly changing over time, drifting first one direction and then another, until, at some point in time, the population (as a whole, or in part) ceases to be reproductively viable relative to the population at some previous point in time (or geographically separate space). The “break” from one species to the next only appears to be abrupt when viewed through the widely spaced crenelations of the fossil record.

Yeah, I know. It’s old news to everyone else here. But I think that the people to ask for the catchy phrase that would appeal to the uninitiated are those more “recent” converts. Because they are closer to the misunderstanding, they might appreciate more why someone misunderstands. (Yes, good teachers probably know that too.)

I vote for: “Populations evolve, not individuals”.

How about “Individuals reproduce, populations evolve”.

Henry J said:

How about “Individuals reproduce, populations evolve”.

‘nuff said!?

A phrase I’ve often seen floating around here sometimes is reproduction of the good enough. I’m surprised it hasn’t been mentioned yet.

Anyway, before I click on the link to the article in question, let me see if I can predict some of the other irritating terms.

missing link

living fossil

more evolved/less evolved

de-evolution

micro-/macro-evolution

Another problem, not limited to a single term, is teleological language in general. i.e. gazelles evolve speed because they want to evade the cheetahs. As if their desire had anything to do with it.

Well, I got three of the four. :)

Paradigm Shift.

As long as I live, I never want to hear the phrase “Paradigm Shift” ever again.

Fuck you, Thomas Kuhn.

Scott F said:

I think that phrase (or some variation) ought to be “it”: “Populations evolve, not individuals.”

The phrase is clear, concise, catchy, and most importantly, it’s true. It avoids, contradicts, and explains the misconceptions of both, “If people evolved from monkeys, why are there still monkeys”,

I don’t agree. A set of individuals will encompass all the events affecting those individuals (including mutations), but this does not by itself encompass evolution. To encompass evolution, so that it becomes meaningful to say “populations evolve”, we must extend the abstraction of a “population” over time, such that we can include individual 1 and its great-great-grandchild individual 2 in the “same” population, even when 1 and 2 never lived at the same time. This condition of continuity over time is hidden inside your concept of population.

Now we can consider something like an origin-fixation event, in which a mutation emerges and, over time, spreads through the “population”, so that some successor type has replaced a progenitor type.

This presents 2 problems with the argument you have presented. If, during an allele replacement, successors replace progenitors, then why doesn’t this always happen? Why are there still chimps if humans evolved from chimps?

That question is perfectly legitimate. It is not based on a misconception. It is a logical question that any philosopher would ask upon seeing your model. The answer is that it is not sufficient to attribute evolution to shifting gene frequencies in a population. At least, one must include the concept that there are isolating mechanisms that split one population into two.

The second problem has to do with the hidden concept of time-continuity. Which is more important for understanding what is essential about evolution, the “aggregating individuals” aspect of your concept of “population”, or the “continuity over time” aspect? Clearly if we are considering asexual organisms (i.e., most of the earth’s organisms) we can invoke the abstraction of a “lineage” that has continuity over time but is not a population. A “population” of asexual organisms is merely a collection of lineages. They are not necessarily independent, but they could be largely independent. Obviously, asexual organisms can evolve, even though there is no (or little) cohesion in asexual populations.

Can “evolution” be said to happen in a lineage? There are some reasons why I would not say “yes” unequivocally, but I think this issue reveals that the “genes mutate, populations evolve” catechism of the Modern Synthesis does not really get to the heart of the matter– this is more about Modern Synthesis apologetics (i.e., drinking Ernst Mayr’s kool-aid) than about developing a philosophically coherent system for considering genetical evolution.

Yes! This:

AltairIV said:

Another problem, not limited to a single term, is teleological language in general. i.e. gazelles evolve speed because they want to evade the cheetahs. As if their desire had anything to do with it.

I am very excited to see more labs start to study the difference between selection on new mutations, and selection on standing variation.

If an individual has a mutation conferring a ten percent reproductive advantage there is a twenty percent chance that mutation will eventually spread through the entire future population.

I feel this statement answers most of the concerns raised. But I admit it is neither catchy nor concise. So what follows are some attempts at catchy and concise that admittedly leave behind some accuracy: Mutations are hard. Evolution is easy. Populations can evolve rapidly once they get that special allele. A population will take an advantageous mutation and run with it. Population army is only looking for a few good men. (Evolution will make the rest of them good). One North European got a mutation conferring lactose tolerance. Evolution gave that advantage to nearly the entire European population.

Am I even getting close?

This is how I meant for that to look:

Mutations are hard. Evolution is easy.

Populations can evolve rapidly once they get that special allele.

A population will take an advantageous mutation and run with it.

Population army is only looking for a few good men. (Evolution will make the rest of them good).

One North European got a mutation conferring lactose tolerance. Evolution gave that advantage to nearly the entire European population.

Sorry.

Mutations and recombination increase genetic variety.

Selection reduces it. (Genetic drift also reduces it.)

Positive feedback between the two can increase or decrease the intensity of a given trait, which can resemble optimization of something.

Yeah, I know that’s not concise or catchy, but concise and catchy will always leave out details that are needed to actually understand it.

Evolutionary change may be understood as a dual process of the introduction and reproductive sorting of variants, where “reproductive sorting” covers selection and drift, and the introduction process implicates mutation and altered development.

This process takes place in some environment (which may be complex and variable), and often is compounded by the presence of multiple hierarchical levels of variation and reproduction.

How about this with regards to selection and adaptation:

“Those that didn’t aren’t.”

Not very detailed, but succinct.

Ugh. We must emphasize that evolutionary theory is our only way of understanding biological complexity. We must address two features of biological structures:

1. Their complexity.

2. Their adaptation.

These two are not the same thing, because complexity may be non-adaptive. If an insectivore had one arm for climbing and another that evolved into a wing (which is in fact what creationists say evolution “requires” transitional fossils to look like), then that would be very complex indeed, but not adaptive.

Complexity (specifically Kolmogorov complexity) is a measure of non-duplication, non-redundancy. If an exactly duplicated part is modified so it is no longer identical to the other part it was duplicated from, then that is an increase in Kolmogorov complexity– but not necessarily adaptive. It may or may not be adaptive.

For example, if we start with a repetitive sequence, ABCABCABC, a random mutation might change that to: ABCABXABC. That is less duplicative and thus more complex, but not necessarily adaptive.

To generalize: if a sequence starts out duplicative (e.g. due to observed processes of gene duplication), then random mutations, ON AVERAGE, will INCREASE COMPLEXITY (but not necessarily adaptation) by the Kolmogorov criteria.

What, then, increases adaptation? Natural selection, because adaptation is closely related to a particular measure of “information”. Information can be quantified as the distance (specifically Kullback-Liebler divergence) between the distribution of fitnesses in a population, and the distribution of fitnesses in hypothetical random genomes (which would be mostly dead.)

That is, think about the distribution of fitnesses in all the alleles of a gene in a population. Most are viable, some will have decreased fitness or be lethal, a small number may have increased fitness.

Now think about the distribution of fitnesses in a set of random scrambled sequences of the same length as the gene. Most have reduced or zero fitness; whether they are mostly lethal will depend on the gene, but if the gene is essential, most random scrambles of it will be lethal. A very small fraction will be viable.

How far apart are those two distributions? The information in the population is determined by how far apart the distribution of fitnesses in the population is from the distribution of fitnesses in the hypothetical random scrambled set. This is a measure of the adaptation of the population. Let’s call this adaptive information.

Now, to describe what random mutation does, as compared with what natural selection does, we must distinguish between the properties of individuals versus the properties of populations.

As I described it above, adaptive information can only be a property of populations, never of individuals.

Complexity can, in principle, be a property of populations or individuals– but if we imagine a single “random” mutation, that affects the complexity of AN INDIVIDUAL not a population.

Thus we summarize that evolution increases BOTH:

1. Random mutations on average increase the COMPLEXITY of individuals. On average they DECREASE the adaptive information of the population.

2. Natural selection INCREASES the adaptive information of the population, because NS pushes the distribution of fitness values in all the alleles in a population farther away from the distribution of fitness values you would expect in a hypothetical set of randomly scrambled genes. Increased distance (to be precise, Kullback-Liebler divergence) between distributions of fitness values are by definition an increase in information.

Evolution of super-complexity and super-adaptation is possible when the gain in adaptive information in natural selection is greater than the loss in adaptive information due to random mutation. This will be true only for certain values of mutation rates and for certain selection coefficients. For example, for hypothetical extremely high mutation rates and low selection coefficients, “devolution” or degeneration would probably occur, as creationists claim. However, in the real world of biology, mutation rates are very low and selection coefficients sometimes high. So there’s no reason why Australopithecus afaransis can’t evolve into Homo habilis.

However, in the real world of biology, mutation rates are very low

Yeah, I’m guessing that species with high mutation rates don’t last long.

I like to think of evolution as an application of Theseus’ Boat. You can never catch the boat in the act of ”becoming” another vessel, but the builder (or knowledgeable observer) of the ”original” boat would be able to spot the change instantly on Theseus’ return to Crete.

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This page contains a single entry by M. Wilson Sayres published on April 22, 2013 10:01 AM.

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