First passage from the set, and this one is not so bad. The argument structure in this passage is incredibly straightforward.

It's about as straightforward as it gets on the LSAT.

And despite the fact that this is a science, biology, natural selection passage,

there's actually very, very little science that you actually need to know at all.

So don't be scared off by this. For timing, I think 5 to 6 minutes for this passage.

So, let's take a look.

You just can't reduce evolution to natural selection. Evolution is more than just natural selection.

So, you know, this had better not be the first time you're reading about evolution, right?

I mean, if you've done any RC prep at all, it's like every other science passage about evolution.

And I mention this because there's another reason why this passage has to go pretty fast.

Like, this bit here, this has to just be like background information you already had.

Anyway, so back to this. Natural selection has been the main but not the exclusive means of modification, right?

Darwin said, look, it is the main method of modification, but it's not the only method of modification, he declared.

Nonetheless, a group of self-proclaimed strict constructionist Darwinians has risen to the promise by reducing Darwin's theory in just this way.

So, this is not going to go well for these strict constructionists, right?

I mean, they're contradicting the guy who wrote the book on this.

So our author is probably going to spend the rest of this passage convincing us why these guys are idiots.

So these theorists use the mechanism of natural selection to explain all biological phenomena.

All bi—it's not—it's—you know, look at the way the author is setting us up.

When you say that these strict constructionists use this theory to explain all biological phenomena—

to be wrong—do you see how easy it is to be wrong on this point?

You just need to show me one biological phenomena that is not explainable by the mechanism of natural selection, then we're all set, right?

They assert—so here we're just—before the author tears apart their argument,

the author is giving us a clear view of what their argument actually is, right?

Very standard LSAT practice.

They assert that natural selection is responsible for—here we go—every aspect of every species form and behavior.

I mean, look at this. Are you serious?

Every aspect of every species form and behavior—like, the fact that we have forearm hair.

What the hell is forearm hair there for, right?

That that is supposed to be like a reproductive, like, advantageous thing to have, right?

That's ridiculous, right?

So, first point.

Second point, for the success or failure of species in general, right?

So, for, you know, for every aspect—like, your—the length of your hair, the color of your hair, the fineness of your skin, right?

Every form, every behavior, right?

Your reaction to bears, although that's probably a survival advantage.

That's one point. Second point is, generally, just whether your species even exists, right?

Has continued to survive, right?

So, these are the two points, and now let's see the author take them down.

Yes, we already know this.

If strict constructionists are right, the persistence of every attribute—this is sort of like a just repetition of this, right?

Every attribute, survival of every species are due to such adaptation, but—so, here we go.

Author starts to tear down the strict constructionists at this point.

But, in fact, nature provides numerous examples of attributes that are not adaptations for reproductive success,

and species whose success or failure has little to do—you know, I already mentioned, like, forearm hair.

Just think of some, like, you know, or like the fineness or the coarseness of your skin, right?

Just, like, really accidental random things.

and others produce harmful attributes and thus are weeded out—see, the author is—

while it is true that, you know, although it's true that, I can see this point to you, right?

We've seen this language being used for—these are not points that help the author's argument.

Author's just sort of, like, clearing the air, getting this stuff out of the way.

Obviously, there are some random mutations that natural selection will favor,

and some that natural selection will disfavor, right?

The vast majority fall into neither category.

We know from—right? We now know from population that most mutations—most mutations fall into neither.

They're neither good or bad. They're just random.

Research has revealed that neutral, non-adaptive changes account for a large extent of evolution of DNA.

Most substitutions of one unit of DNA for another within a population has no effect on reproductive success, right?

Like, all the random mutations that are happening in the DNA, most of them are, you know, like they say, neutral.

No effect on reproductive success.

But these alterations often change the attributes of species, right?

You know, again, forearm hair, coarseness of skin, right?

But their persistence from one generation to the next is not explainable by natural selection

because they've just no effect on reproductive success, right?

So that's one point. That's this, like, every aspect of every species' form and behavior.

See, this is a teardown of this point of the strict constructionist.

success or failure of species in general.

Author is going to claim that is also not right.

The study of mass extinction in paleontology undermines strict constructionist claim

that natural selection can account for every species' success or failure.

That was point number two.

Okay, how?

The extinction of the dinosaurs 65 million years ago is probably caused by the impact of an asteroid.

Smaller animal species generally better able to survive catastrophic change in climate

that we would expect to follow from such an impact once the asteroid impacts.

And like radioactive ash clouds cover the earth, cooling, climate cooling, blocking out the sun.

So all of these things that happen as the aftermath of the impact,

smaller animal species just happen to be better able to survive.

And why were the animals so small?

Is it because they anticipated the impact of the extraterrestrial—

like, you know, the animals conspired to breed with small animals only to keep their sizes small

because they anticipated, you know, the foretelling of the eventual impact?

No, that's ridiculous.

It's because they just cannot compete on the same scale as the dominant dinosaurs.

The only way for them to survive is to remain small.

That was the environmental pressure exerted on mammals.

But while the scenario explains why dinosaurs died off, mammals fared relatively well,

see, what we just talked about right here, that's the hypothesis.

That is the story you tell for why small animals fare well, whereas large dinosaurs didn't.

That's not the strict constructionist view.

Where did natural selection come in?

It does not conform to strict constructionist view of adaptive reasons for the species.

See, because, you know, here's what it would look like to conform to that view, right?

To conform to the strict constructionist view, you'd have to say that adaptations are a response

to conditions that are already in place at the time that the adaptation occurs.

In other words, the potentiality of an asteroid impact, right?

And mammals could not have adapted in advance to the conditions caused by the impact, right?

And there's just no way.

In a sense, our author concludes, their success, the mammal's success, was just a result of dumb luck.

Well, okay, I mean, yeah, it's a fine argument, but I feel like that's probably not fair to dinosaurs.

First question to be expected. Main point question. We know the main point is these guys are just wrong.

The natural selection is the only driving force behind evolution. Yeah, so they described the claim

correctly over here, right? This is the correct description of the claim. Two areas of science.

Yes, we have from genetics, DNA, genetics, and also paleontology. These are very different

areas of science. So there you go. Choose it. Then you kind of just scan it because this is

so obviously right. You kind of just scan the rest, quickly get through the rest. According

in most. What? How can that be the answer to the main point? The main point has to be,

you know, you guys are wrong, right? So forget the details here. It's wrong on a higher level.

See, again, you're not talking about the strict construction list. You're just,

you're not even on the same level. Strict constructionist followers, Darwin,

point. You have to say you can describe their views like A does, but then you have to say

they're wrong, right? You have to say that they're wrong. Evidence from study of population

I mean, this bit is incomplete, but accurate, right? This bit is incomplete, but accurate.

Sure. We do have evidence from study of population genetics and evidence from

paleontology, right? That would be a complete and accurate. Here's just accurate, incomplete

to disprove the claim, right? And here you got to replace all this bit with of the strict

constructionists, right? Then this will be, so this is it just, this is not what the strict

constructionists would say. So a couple of points wrong about E.