Showing posts with label evolution. Show all posts
Showing posts with label evolution. Show all posts

Monday, July 19, 2010

The fruits of accomodationism?

PZ and Jerry Coyne have both discussed the PLOS paper on a survey of high school biology teachers in the US.

The graphic I want to discuss is here:


If we remove those who failed to express an opinion (the same in both surveys - 9%) we can do a "triangle plot" or Ternary plot, showing the three other percentages:



On this plot, moving up is "more creationism", moving (roughly) southwest is "more acceptance of evolution" and moving southeast is "more acceptance of ID".

We see that the general public (in blue) and the high school biology teachers (red) are not in the same place. We can't from this tell for sure whether it's the training of biology teachers and the materials and curricula that they have to work with that makes a difference or whether those who might become biology teachers are a priori different from the rest of the population, but numerous anecdotes (which attest to the fact that education does change people's opinions) suggest that training and the teacher's available teaching materials (like textbooks and so on) and curricula will have a substantial impact on what positions they will endorse. Cognitive dissonance is a powerful motivator.

Since training at a university level will generally tend to be based directly on evolution rather than be ID-oriented, while school-level teaching materials and curricula will tend to be more influenced by (for example) NCSE policy, one has to wonder at the overall effect of the two.

If we attribute the shift between the red and the blue points largely to effects other than pre-disposition, we must say that these have produced a shift away from Creationism... but not even slightly shifted toward the position of actual biological science relative to ID.

The suggestion that I take away from this is that this may be in part to the effectively accomodationist stances of influential organizations like the NCSE - by openly tolerating, sometimes even advocating unscientific positions like ID (that God "guides evolution", rather than the scientific position of evolution operating by natural selection, sexual selection, genetic drift and so on is basically ID), they merely succeed in replacing one load of unscientific nonsense with another.

This is not science education.

Enough with accomodationism. Let's advocate actual science, and get everyone's favourite god(s) out of biology class.

Even though I am in Australia, this sort of thing has particular relevance for me because the Australian school curriculum in under review right now... and while the science curriculum is safe, look what's in the senior History curriculum:

UNIT 2A, pg 8

Controversies

Students develop their historical skills in an investigation of TWO of the following controversial issues:

a) human origins (e.g. Darwin’s theory of evolution and its critics).

b) dating the past (e.g. radio-carbon dating, tracing human migrations using DNA)
...


Yep. Maybe if we looked at the controversy itself as historical, this would count as 19th century history. But this is the Ancient History curriculum... as if human origins and radio-carbon dating are actually substantially in doubt now as being useful for informing us about the past - as if we don't really know these things quite well, and as if actual human origins (and carbon dating, for crying out loud) were at issue.

If these are controversies, why not look at the flat earth/round earth controvery, and while we're at it, germ theory too?

I think accomodationism is poisoning our education, by trying to make us accept as equally reasonable points of view that have nothing to do with the actual science.

I think it's insidious. I think it ruins everything it touches.

If it doesn't work, try something else.

Here's an idea - why don't we try NOT being accomodationist for a decade or so. Try actually insisting on science as science - no holds barred. Actually advocate for science. Insist that we teach the accepted scientific positions (and even the parts where there's some actual scientific disagreement if you like) as is. Without trying to fit in everyone's pet unscientific ideas as well, just because it makes them feel all warm-and-fuzzy.

Let's see what happens.

Monday, April 5, 2010

Human Brain Evolution - a clear kink

Jerry Coyne has discussed human brain size evolution a couple of times recently, the latest one here.

Anyway, I grabbed the data from Lee and Wolpoff (2003) ("The pattern of evolution in Pleistocene human brain size", Paleobiology, 29(2), 2003, pp. 186–196), read it into R and looked at log brain size (since linear trend on the log scale corresponds to constant percentage growth). If there was a sudden jump in growth rate, it should show as a kink.

I then used the lowess function (which is a form of locally-linear regression) in R to smooth the data, to hopefully identify any such kinks and see where they fell. I used the default value of the smoothing parameter (f = 2/3). I then tried a range of other f-values, and all values between roughly 0.5 and 0.8 (a fairly wide range, so the conclusion is robust to the smoothing parameter) give very similar-looking fits, and a clear kink at the same x-value:





The smooth shown in green here is for f = 0.8

(Click the image for a larger version)

With this analysis, the kink plainly appears at 300 thousand years ago (but the ages of the observations are approximate and subsequently rounded).




There does seem to have been a substantial acceleration in growth in brain volume approximately 300 thousand years ago.




Edit: Here's a link to a somewhat related article at Panda's Thumb from some years ago, based on a different paper. Much of the data is the same, but contains additional information.

Thursday, September 3, 2009

"Why Evolution Is True" mini-review

I recently bought Coyne's book "Why Evolution Is True". I had not planned on finishing it quite so quickly, but an enforced 5 days in hospital made short work of it; I could have read it four times over.



Overall: It's a solid covering of a lot of both the evidence that evolution has occurred (and continues to occur), and the evidence that a major driver of evolutionary change is natural selection. It's clearly and engagingly written - the level is a bit lighter than I'd like (there are many places where just a bit more detail and depth would help), but probably spot on for the audience it's aimed at.

Nits: Actually, I have quite a lot of nits to pick. I won't list them all just now (I may visit some in a later post), but they're mostly minor. I'd love to have seen more on ERVs, for example. A number of assertions are made that really should have some evidence to back them up -- and at least one of those assertions is, I think, very likely wrong, and reads like accomodationism. (Coyne is no accomodationist, which makes it seem weird.)

Who this book is for:
- anyone who wants to learn what evolution is, what is the evidence that it happens, and why natural selection is such a powerful explanation of it.
- anyone who finds themselves in the position of having to try to explain to someone else what evolution is, ... and so on. This includes me. The moment a creationist finds out I am interested in science, I'm enthusiastically Gish-galloped. This is a good start on background for being able to give better responses than my original laser-like response of "uh-whuh-huh?".
- anyone who wants to argue that evolution is wrong. This is a basic introduction to what they have to try to argue against - that straw man they currently pound makes them look like morons.

In short, "Why Evolution Is True" is an enjoyable book. Well worthwhile, even at the relatively exhorbitant price I had to pay for it in Australia.

Wednesday, August 19, 2009

Finally managed to get hold of "Why Evolution Is True"

I've been trying to get hold of Why Evolution Is True" for months and months... and I finally found a copy. It was always "[typity-type] oh, our store in outer Mongolia has a copy. Or I could order it in for you... (... for $45)".

Anyway the bookstore on campus actually finally got it in. Yay. $46 (WTF!?) but with discount it was just under $43 ($35 US - yeah, I should have just waited 4 weeks and I'd be in Chicago and could have got it for heaps less, or even had it shipped from the US by Amazon, for that matter). But anyway, I decided not to wait and just get it.

Haven't had much time to read it, but the little I have read so far is very good.

I have put Darwin aside for a little (I'm about halfway through), because reading Darwin constantly had me saying "but don't we know such-and-such now?" - I really wanted to have a better understanding of current evolutionary ideas; actually I'm not too badly off, since I read around a fair bit, but it's always been in tiny disconnected pieces - this book of Jerry Coyne's looks like a good laymans overview.

Thursday, August 28, 2008

Transitional forms

Creationists deny transitional forms by asking for evidence of implausible chimeras - "half-fish, half-cow" and the like. That's like denying that coffee cools down because there's no time at which half the cup is scalding and the other half is cold.


[The plausible transitions - that is, actual transitional forms, such as lineages of fossils displaying characteristics of both fish and amphibians, for example - are not asked for much these days - because there are far too many of them, and more all the time.]


(Related post: A creationist looks at Janie's photo album)