In case the newspaper photos weren’t enough, here is a video clip of the pelican-pigeon encounter.
I doubt if the whole incident took anything like the 20 minutes claimed by some witnesses. Eye witnesses are notoriously bad at estimating the duration of events. Based on the video clip, I guess it may have taken up to 5 minutes.
This week’s Ask a ScienceBlogger:
What’s the most underfunded scientific field that shouldn’t be underfunded?…
I’ll say old fashioned biological anthropology. There’s a reason that a pall was cast over thsi field after World War II, but we need to start pushing an analysis of man the animal on all levels again, as the post-genomic era is starting with an explosion centered on the most important animal of all, and the moment is ripe for the re-emergence of complementary fields.
There is a working paper out which reports on the nature of the religiousness of the professoriate. Some data of interest….
* Proportion of professors with “No religion” – 31% (vs. ~10% for the general public)
“I don’t believe in God” – 10% (vs. 2.8% for the general public)
“I don’t know whether there is a God, and I don’t believe there is a way to find out” – 13.4% (vs. 4.1% for the general public)
“I don’t believe in a personal God, but I do believe in a Higher Power of some kind” – 19.6%
“I find myself believing in God some of the time, but not at others” – 4.4%
“While I have my doubts, I feel that I do believe in God” – 16.9%
“I know God really exists and I have no doubts about it” – 35.7%
I just received a review copy of Saxons, Vikings and Celts: The Genetic Roots of Britain and Ireland. I won’t be talking about it until January as I’ve agreed to hold it until it starts being marketed after it’s published here in the states. But, I do think it is kosher if I report the data which Bryan Sykes repeats from the 19th century work The Races of Britain.
1) Blonde hair is most common in East Anglia and Lincolnshire, with high values in Yorkshire, Cumbria, the north of Scotland and the Hebrides. It is least common in Ireland and Cornwall. Intermediate values can be found in most of England and Wales.
2) When it comes to eye color the cline is different. Brown eyes are common in the south and the east, where they exceed 40% in East Anglia and Cornwall. In Ireland, Yorkshire and Cumbria the frequency of blue or grey eyes rises to 75%.
If you want a genetic moral from all this it is that eye color and hair color are not closely linked. There does seem to be some correlation between areas with a high frequency of red hair and light eyes (e.g., Scotland), but that is likely because the former trait is derived from a serial loss off function for melanin production on several loci, and light eyes are a natural byproduct of this genetic architecture. There are implied modal combinations, such as many dark eyed blondes in East Anglia, and the dominance of dark haired but blue eyed folk in Ireland, and the dark eyed and dark haired Cornish. Since I have British readers I will leave it to them to judge the accuracy of these ascertainments, though keep in mind that the data was collected in the late 1800s, so population movement might have homogenized the distribution of traits a bit.
We’ve received a lot of search engine traffic over the past few days because of the phenomenon of “black” and “white” fraternal twins (two cases within the last week). Aside from the original post on this blog, I’ve commented on it a few times at my other blog, here, here and here. Also, some of you might find this 20/20 segment on the original British twins interesting, click on the video. I can’t but help wonder if Brazilian readers don’t find the commotion a bit amusing…
There’s another article in Science about women and science.
It appears to consist predominately of (1) rebuttals to straw-men arguments and (2) Lewontin-like claims that we’re all the same despite our differences. A great deal of the text deals with describing (without much detail) male-female differences on a variety of criteria.
The magnitude of each gender difference was measured using the d statistic (6), d = (MM – MF)/sw,where MM is the mean score for males, MF is the mean score for females, and sw is the pooled within-sex standard deviation. The d statistic measures the distance between male and female means, in standard deviation units.
They list a variety of metrics on which the sex-difference (measured in d) is small. They fail to mention the male advantage in spatial ability, but do mention the male advantage(?) in aggression. While focusing on differences in measures of ability among children, they relegate discussion of tail effects to the supplemental online text. There they mention tail effects as an effect of differences in variance, but ignore the fact that mean differences also cause tail effects.
Rather than dig any deeper into this paper, I will present what they chose to ignore: the theoretical effects of small differences in mean and variance between males and females will produce large differences at the tails of a normally distributed trait.
This table presents the percentage of females above a +3 SD threshold as various differences in mean (pink) and SD (orange) in standardized units units. Thus, if the mean and SD are equal (0,0) then women make up 50% of the population above 3 SD on this imaginary trait. But if d=0.3 and males have a variance that is 0.06 SD units greater than women, then the female percentage above 3 SD will be 17.1%. A d of 0.3 is labeled “small”, and an SD difference of 0.06 (women SD = 0.97, men SD = 1.03) would be hard to establish in small samples. Nonetheless, it would produce exactly the kind of large differences in male:female ratios among the most talented individuals that we observe in math-heavy disciplines.
| 3.00 | 0.00 | 0.02 | 0.04 | 0.06 | 0.08 | 0.10 |
| 0.00 | 50.0% | 45.1% | 40.3% | 35.6% | 31.2% | 27.1% |
| 0.05 | 45.9% | 41.1% | 36.4% | 31.9% | 27.8% | 24.0% |
| 0.10 | 41.9% | 37.2% | 32.7% | 28.5% | 24.6% | 21.1% |
| 0.15 | 37.9% | 33.4% | 29.2% | 25.2% | 21.7% | 18.5% |
| 0.20 | 34.1% | 29.9% | 25.9% | 22.3% | 19.0% | 16.1% |
| 0.25 | 30.6% | 26.5% | 22.9% | 19.5% | 16.6% | 14.0% |
| 0.30 | 27.2% | 23.5% | 20.1% | 17.1% | 14.4% | 12.1% |
| 0.35 | 24.1% | 20.6% | 17.6% | 14.9% | 12.5% | 10.4% |
| 0.40 | 21.2% | 18.1% | 15.3% | 12.9% | 10.8% | 9.0% |
| 0.45 | 18.6% | 15.8% | 13.3% | 11.1% | 9.3% | 7.7% |
| 0.50 | 16.2% | 13.7% | 11.5% | 9.6% | 8.0% | 6.6% |
Afarensis points me to this new story in National Geographic about the Neandertal sequencing effort:
A new study by geneticist James Noonan at Lawrence Berkeley National Laboratory, however, reveals that modern humans and Neandertals’ most recent common ancestor probably perished about 400,000 years ago.
…
Noonan’s work represents a significant advance over earlier studies of Neandertal genetics, such as those conducted by William Goodwin of the University of Glasgow in Scotland….That early work involved analysis of mitochondrial DNA, which tends to stay preserved longer than DNA found inside the nuclei of cells. But Noonan analyzed nuclear DNA, which holds a much greater wealth of information.
…
Based on his results to date, Paabo expects to see some surprises as his project proceeds.“Neandertal DNA is degraded in specific ways that we had not anticipated, and in some ways Neandertals actually look closer to humans than we had expected,” he said.
What could Paabo mean??? Stay tuned over the next few weeks….
I noticed today that I was receiving a lot of search engine queries for black and white twins. Well, I have posted on it several times, but I thought it was a bit much, so I checked the news, and lo & behold, another case just popped up. Like the Australian twins the mother here was biracial (Nigerian and English) while the father was white (in contrast to the earlier British case where the parents were both biracial). I’m sure you’re getting tired of this, but I have to comment when I see headlines this: Mum defies million-to-one odds to give birth to black and white boys. I’ve posted on it, and the odds in this particular case are not “a million to one,” and since you’ve had three recent cases in the public eye within the past 6 months you would figure that we would re-evalute our priors here in regards to the expectation of probability.
But in any case, I did think it was worth posting on this specifically because this pair of “black” and white twins were male and not female.1 What if they mated??? Let’s focus on skin color here, since that is what people are focusing on:
Dark + Light = ?
Dark + Dark = ?
Light + Light = ?
