Evolution does not stop

One thing I often hear regarding evolution is the notion that it can end. That is, I hear people make the claim that in one way or another, a species can (or has) reached a point where it will no longer evolve. This idea is generally applied exclusively to humans, but perhaps advocates would extend their arguments. I’m not sure. At any rate, it’s a surprisingly popular claim. Geneticist Steve Jones even made a version of it. He was speaking more of rates than anything, and I’m likely to chalk up his statements to hyperbole, but he did title one of his talks, “Human Evolution is Over.” Unfortunately for him, he’s wrong.

Evolution at its most basic is the transmission of genes from one organism to another. That isn’t to say individuals can evolve – they can’t – but broken down to its constituent parts, evolution is the flow of alleles from one vehicle (individual organism) to another. So long as that is occurring, evolution is occurring. To put it another way:

Evolution happens every single time an organism reproduces.

Evolutionary rates – generation time, mutational rate, environmental pressures, frequency of drift, etc – will vary from species to species and over great swaths of time, but they can never reach zero for any given population unless that population ceases to exist. At the point where members of the group no longer produce offspring is when evolution stops. It is literally the only time it can stop.

The fact is, evolutionary theory is the most integral part of the field of biology. The famous Theodosius Dobzhansky paper and now phrase, ‘Nothing in biology makes sense except in the light of evolution’, couldn’t be any more true; from the moment the first replicator evolved into something more, evolution has not once taken a break. So long as there is life, there is evolution.

The confusion over Steve Jones

Steve Jones has, according to media reports, made the claim that human evolution has stopped, or is at least slowing down in the West. At times we see conflicting statements from Jones himself over this.

I really just know about snails, and the beauty of evolution is that it gives biology a structure, so the rules that apply to snails or to fruit flies to some extent apply to ourselves. Obviously there’s much more that applies to us. But if you ask the simple Darwinian question about natural selection, inherited differences in the ability to pass on genes (which is only part of the evolutionary argument) it’s pretty clear to me that at least for the time being and at least in the developed world, natural selection has stopped or at least slowed down.

First, snail evolution is quite beautiful. Second, we see here that Jones is referring to natural selection, not evolution. Some sort of argument can be made that there is much less selection pressure on humans in Western nations than there was in the past. Of course, that wouldn’t be a very satisfying argument since natural selection is still ‘weeding out’ people with certain diseases and predispositions. It’s just that some of them, depending upon their economic situation as well as their particular affliction, happen to have reduced overall selection pressure on their alleles. But even then, there are people with diseases which will kill them before they get a chance to reproduce.

At any rate, this whole argument becomes rather moot because Jones also goes on to specifically speak of evolution rather than just one of its mechanisms. In fact, his talk is titled “Human Evolution is over”. He is wrong. Even if we were to ignore all the problems involved with making an argument that natural selection is over in humans (in the West), the evolution-is-over argument still does not fly because evolution is not simply selection. Genetic drift and mutation are two other major mechanisms. While he seems to ignore drift, Jones does, however, argue that there are fewer mutations in the population. His argument goes like this.

Men are fathering children at far younger ages than they did in the past. Given the fact that mutations accumulate in a person over time, these young men have fewer mutations than older men. Thus, subsequent generations are inheriting fewer and fewer mutations.

Okay, the first question which comes to mind is “So what?” The mutation rate of younger fathers is still, by far, substantial enough to maintain the continuing of human evolution. There is no shortage of mutations in each and every person at birth. Jones probably was born with around 100 mutations. You, too.

The second thing which comes to mind is to wonder why Jones would first make this age-mutation argument, but then go on to argue this.

Similarly, child survival rates, abysmal in antiquity, have dramatically improved in much of the world, cutting natural selection pressures.

In other words, more people live to reproductive age. This means there are more people reproducing, which means more mutations. His argument is dreadfully weak.

One wonders why such a quality scientist would make such a poor proposition.

John Lott is wrong again

It has been well-documented that John Lott is a big, fat liar. He writes slanted pieces to pursue his own agenda, not truth. So it comes as no surprise that he would post an article on his blog which claims that an Obama advisor is “wacky” for being concerned about global warming. Okay, so no big deal. Just another ignorant mook that cites non-scientific sources in order to pursue lies. Sure, it’d be nice if he would just go and post at Conservapedia, FOX News, or WorldNetDaily, but the whole concept of free speech does allow for anyone to speak his mind, even if the thoughts within said mind are utterly ignorant. Ignorant how? As is so common (especially among conservatives – extra-especially among FOX News conservatives), John Lott is ignorant in science. In this case, it’s sun spots.

First let’s note how Lott cites an article from Investor’s Business Daily (that highly regarded scientific organizati…business newspaper). He excludes eight grafs on his blog. Three of the grafs are either introductory or conclusion grafs. The other five are as follows.

The Little Ice Age has been a problem for global warmers because it serves as a reminder of how the earth warms and cools naturally over time. It had to be ignored in the calculations that produced the infamous and since-discredited hockey stick graph that showed a sharp rise in warming alleged to be caused by man.

The answer to this dilemma has supposedly been found by two Stanford researchers, Richard Nevle and Dennis Bird, who announced their “findings” at the annual meeting of the American Geophysical Union in San Francisco. According to them, man not only is causing contemporary warming. He also caused the cooling that preceded it.

According to Bird and Nevle, before Columbus ruined paradise, native Americans had deforested a significant portion of the continent and converted the land to agricultural purposes. Less CO2 was then absorbed from the atmosphere, and the earth was toasty.

Then a bunch of nasty old white guys arrived and depopulated the native populations through war and the diseases they brought with them. This led to the large-scale abandonment of agricultural lands. The subsequent reforestation of the continent caused temperatures to drop enough to bring on the Little Ice Age.

Implicit in this research is that the world would be fine if man wasn’t in the way. We either make the world too cold or too hot, a view held by many in high places.

Given the derisive nature of these grafs, it may actually may have made sense for Lott to publish them, but two of them contain some contradictory science to his silly dogma. That just doesn’t fly for these global warming denialists. I’m beginning to think Lott maybe does visit Conservapedia.

So now that we have Lott’s continued dishonesty out of the way, let’s tackle the main issue: sun spots. The unscientific, babbling article the unscientific, babbling Lott cites tries to stake a claim that all this hoo-hah about global warming is really just scientists misinterpreting data because they never considered sun spots.

When the sun is active, it’s not uncommon to see sunspot numbers of 100 or more in a single month. Every 11 years, activity slows, and numbers briefly drop near zero. Normally sunspots return very quickly, as a new cycle begins. But this year, the start of a new cycle, the sun has been eerily quiet.

The first seven months averaged a sunspot count of only three and in August there were no sunspots at all — zero — something that has not occurred since 1913.

According to the publication Daily Tech, in the past 1,000 years, three previous such events — what are called the Dalton, Maunder and Sporer Minimums — have all led to rapid cooling. One was large enough to be called the Little Ice Age (1500-1750).

(Don’t worry, Lott posted that part).

Okay, so because there are few sun spots to be seen toward the end of this current solar cycle and global temperatures have dropped in 2008, global warming is due to that. There are so many things wrong with this it makes me mad.

First of all, this horrific article cites the first seven months of this year. Guess what? Those months correspond to the end of the last solar cycle. It wasn’t until the past three months that the new 11-year cycle was detected (Hey, John, that’s a scientific citation; use it sometime).

Of course, it’s possible to go so far as to use the misleading information provided by this business newspaper and still show it to be wrong. Let’s assume this solar cycle does correspond with the change in global temperature. It would necessarily follow because there was a rise in temperature in the first seven years of this century that there was also a rise in solar activity. In truth, this past 11-year solar cycle peaked in 2000 and has been decaying ever since. Wow! The wonder of slight research and knowledge! Oh, how it destroys ignorance so quickly. It’s too bad John Lott isn’t interested in doing that.

What’s more, this article cites the Little Ice Age, as if it was entirely and decidely caused by solar activity. The issue is far more nuanced than that – and certainly too nuanced for such an unqualified business newspaper.

Global thermometers stopped rising after 1998, and have plummeted in the last two years by more than 0.5 degrees Celsius. The 2007-2008 temperature drop was not predicted by global climate models. But it was predictable by a decline in sunspot activity since 2000.

Wow. This is just so fucking wrong that it just made me go and fucking swear at its wrongness. Global temperatures have been rising since 1998. From 1995-2006, 11 of the 12 warmest years on record were recorded. As far as this past year goes, it was a decline over the first years of this century – of course, that doesn’t really matter when it was still the 10th warmest year on record. In fact, part of the reason it was cooler than other years was the moderation experienced from La Niña. As is well known (except by John Lott, in all likelihood), water is tremendously useful for retaining temperature. Since La Niña shrinks the warm pool of water in parts of the Pacific, it can make a noticable difference in global temperatures. Still, because of man-made pollution and deforestation, La Niña was not strong enough to prevent 2008 from being the 10th warmest year on record.

It’s unsurprising that John Lott would make a post like this. He has a history of making posts concerning things on which he has no knowledge. Take a look at his posts on evolution. They’re disparate, sometimes contradictory, often with no commentary to give some context. Granted, he shouldn’t be giving commentary on anything, but he also shouldn’t be making posts first concerned with human evolution accelerating and then subsequent posts concerned with human evolution slowing down. Bah. I don’t know why I continue to expect more out of these far-right, a-science mooks.

Novel Information

One of the more “sophisticated” creationists misconceptions about evolution/natural selection (they often conflate the two) is that new information can never be created. This actually has no sophistication in it at all, but it sounds fancy and for that reason it helps to trick a good number of people. It’s especially a shame when it confounds those who want to learn some actual science. So here’s a simple example of “novel information” being added to a genome.

Scientists Decode Cancer Patients’ DNA

ST. LOUIS, Nov. 10 (UPI) — Scientists in St. Louis say they have decoded the complete DNA of a cancer patient and traced her disease — acute myelogenous leukemia — to its genetic roots.

The research team at the Genome Sequencing Center and the Siteman Cancer Center at Washington University School of Medicine in St. Louis said the first-of-its-kind achievement involved sequencing the genome of the patient — a woman in her 50s who ultimately died of her disease — and the genome of her leukemia cells, to identify genetic changes unique to her cancer.

“Our work demonstrates the power of sequencing entire genomes to discover novel cancer-related mutations,” said senior author Richard Wilson, director of Washington University’s Genome Sequencing Center. “A genome-wide understanding of cancer, which is now possible with faster, less expensive DNA sequencing technology, is the foundation for developing more effective ways to diagnose and treat cancer.”

The study appears in the journal Nature.

When a cancer occurs, it is the usually the result of the loss of cell cycle control. Instead of the cell being told to die, it continues to replicate; it may lose its contact inhibition, meaning when an area gets too crowded, cells continue to replicate – this should not happen. There are other ways cancers occur, but they aren’t important for my purposes. What is important is the fact that a change in information in a genome is what caused the cancer in this woman in question. Let’s be clear from the get-go: this is not evolution. Individuals do not evolve. But what this does show is that novel changes occur to genomes all the time.

Recently, Steve Jones said evolution in humans is coming to an end. I haven’t heard his entire presentation, so I’m guessing he thinks it’s actually just slowing down, not ending. But either way, he’s wrong. But I bring him up because the reason why he’s wrong is interesting. He says that the fewer mutations present in reproducing males are contributing to less diversity in offspring. He says this because younger men are reproducing more than older men and older men, especially 35 and older, have more mutations in their DNA. (He later refutes his point by saying survival rates are up, inherently suggesting mutation rate must be up).

So why is this important? It’s important because mutations equal “novel information”. That’s what happens when cancers occur. That’s why the research team sequenced the genome of the woman plus the genome of her cancer cells. There are differences and those differences result in markedly different things. In this case, it’s unfortunate that cancer occurred. In other cases, it’s genetic diversity.

This is a bit of a roundabout way of explaining this, but I hope the point comes across. Cancer is a change in information. It’s obviously a bad one and it doesn’t get passed on in somatic cells, but let’s focus purely on the point: it is a change in information. It is a creation of new information. Although it is bad, it is new and it results in genotypic and phenotypic changes.

How we evolve

Seed has an article about How We Evolve. It’s a fantastic read that I won’t try to break down since it’s already written in an enormously friendly manner. I do, however, want to focus on one part.

“Intelligence builds on top of intelligence,” says Lahn. “[Culture] creates a stringent selection regime for enhanced intelligence. This is a positive feedback loop, I would think.” Increasing intelligence increases the complexity of culture, which pressures intelligence levels to rise, which creates a more complex culture, and so on. Culture is not an escape from conditioning environments. It is an environment of a different kind.

There’s the pervasive notion that human evolution has stopped because we have this flat-seas type of environment where no selection pressure is applied except in the most extreme of circumstances. Indeed, this is a major subject of the article (I guess I did break it down a little). I just find it tremendously unfortunate that even biologists have it in their heads that humans face such limited evolution; the recent comments from Steve Jones are especially disheartening. It’s just something everyone needs to face: evolution happens and nothing stops it except extinction.