Wednesday, 31 December 2008

On reading "On the Origin of Species"

p. 99

I believe that the conditions of life, from their action on the reproductive system, are so far of the highest importance as causing variability. I do not believe that variability is an inherent and necessary contingency, under all circumstances, with all organic beings, as some authors have thought. The effects of variability are modified by various degrees of inheritance and of reversion. Variability is governed by many unknown laws, more especially by that of correlation of growth. Something may be attributed to the direct action of the conditions of life. Something must be attributed to use and disuse.
Some of this passage, the conclusion to the chapter on 'Variation under Domestication', confuses me. I get the impression that what I understand by variation is a more general meaning than that used in this passage.

I also do not know quite what he means by "correlation of growth".

I assume that by "conditions of life" he is talking about deaths by natural causes, and the like.

The comment on "use and disuse" sounds rather Lamarckian. I wonder if it is a throw-away comment, a nod to Lamarck's work.

Tuesday, 30 December 2008

Speed limits on cars

From reading the BBC news article: Calls for 'speed-limiting' car
It talks about a call to add voluntary speed limiting devices to cars. Voluntary is good, and it does suggest that there would be the possibility of overriding the device. That allays my concern that you would find accidents occurring precisely because the device would prevent you from adding that burst of speed to get out of an otherwise unavoidable situation - but only a bit. The time you need the burst of speed is the time when you need a split-second reaction - and if you had to disable the device, you've lost that reaction time.

A while ago I had the idea that a speedometer device could be devised that highlighted the speed limit on the display, perhaps by reading a signal broadcast by speed limit signs. I have something like this already on my sat-nav. It has a record of the speed limits in place (exactly the method suggested in the article), and highlights when my speed (as calculated by the satnav) exceeds the stored limit.

There are a few advantages to my method, I believe. 1) It reads the limit directly from the road, so temporary limits would be recognised, and out of date data in the digital record would be reduced. 2) Having the display directly in front of you would make it more obvious. 3) The satnav calculation of speed is not the speed calculated by the car's built-in system. The built-in system is more accurate - the satellite system is not an instantaneous measurement, but is averaged over whatever the sampling rate is, and includes any inaccuracies in the calculation of position.

Of course, there are downsides. If the limits were broadcast (or, more likely, queried by the devices) from the roadside, it would be possible for rogue limit indicators to be placed by mal-intentioned individuals. However, I do not see that as a huge issue - at worst you'd find that it affected only some signals along some roads. The issue could also be ameliorated by combining the data received from the roadside with data from a satnav-like stored database.

It would also mean that an initial implementation cost was required to upgrade current speed limit signs. Again, a database would mean that cost could be spread over a reasonable period - new roadsigns would have the transponder, and the older ones could be fitted in a long-term upgrade.

I do not know exactly how the transponder would work - I imagine it would be an integral part of the sign, rather than a separate device fitted to the sign. My initial concept had been to have the in-car devices read the signs themselves - optical character recognition should be able to cope with the standard lettering. My other thought was having markings on the road to represent the speed limit that were read by the in-car device.

Anyway, I am sure the government will do something that some group finds ever!

Of biblical aliens

A friend commented that the bible mentions aliens. I was skeptical, so he made a comment about Jesus saying he was leaving Earth and going to tend his "other flocks". I pointed out that that was a rather vague reference if it did in fact mean aliens.

However, I was intrigued, and went to look it up. I think this is the passage he was referring to:
John 10:16 And other sheep I have, which are not of this fold: them also I must bring, and they shall hear my voice; and there shall be one fold, and one shepherd.
The Skeptic's Annotated Bible links this with an almost identical Book of Mormon passage, and says that there it refers to the Nephites. Not entirely convinced of the conclusion there, but it is certainly a fairly general statement, and could mean almost anything.

Pope's Christmas address

"May the divine light of Bethlehem radiate throughout the Holy Land," he said. "May it spread throughout Lebanon, Iraq and the whole Middle East."
(Pope's Christmas address)

One has to wonder if the pope realises that that sentiment is probably quite insulting to those people who are not catholic (at a guess, the majority) in said lands... Or if he is completely oblivious to the tones of "my religion is the only one that matters".

On reading Evolution After the Fact

(link: Evolution After the Fact)
Patrik Nosil gathered “walking stick” insects from one location and put them in another. He and his co-worker found that coloration patterns, such as a white line along the body, changed as they adapted to a new location. Then, the ones that could detoxify leaves of unfamiliar plants survived to “seal the deal” of speciation.
Creationists might agree that the two species in the study had a common ancestor anyway.
(a little after the list of items)

So, we have an experiment which attempts to show speciation happening in the field. The results are perhaps a bit questionable...and in their formal paper they say so.

But I had to do a double take on the latter comment about creationists accepting that the two (or was it just one?) new 'species' had developed from the same ancestor... Surely that was the point that was apparently being refuted.

Monday, 29 December 2008

Thoughts on studying

The OU are doing a short course on "Darwin and evolution" to mark the 150th anniversary of the publication of "On the Origin of Species" (and, iirc, the 200th anniversary of his birth).

I'd like to put some effort into learning more about the supporting evidence - the course seems to focus on that to a degree. They recommend 5 to 7 hours a week; should be possible. That is assuming I actually put my back into it and don't slack off part-way in.

The other question is whether it should be part of a more directed course of study. I did have an idea while walking back from town the other day about a subject that would be worthy of research and something that would interest me wrt evolution. For the life of me I can't remember what it is...

On the definition of "species"

Apparently there are some 18(? must check) definitions for 'species'. The creationist's arguments imply that 'evolutionists' only use one of the definitions - or use the one that suits them at the time...

In the former case, it would be interesting to note any examples of speciation for each particular definition.

In the latter case, well, much the same - but if a speciation event by each of the different definitions can be shown, is that not sufficient to prove that speciation does occur via natural selection?

Things to look up:
1) How many definitions of 'species' or 'speciation' are there (How many does evolution claim? How many do creationists claim?)
2) Examples of speciation under each definition.

Questions from reading "The Origin of Species", Charles Darwin


The same principles are followed by horticulturalists; but the variations are here often more abrupt. No one supposes that our choicest productions have been produced by a single variation from the aboriginal stock. We have proofs that this is not so in some cases, in which exact records have been kept; thus, to give a very trifling instance, the steadily-increasing size of the gooseberry may be quoted.

What proofs was Darwin pointing at? Did he leave records of the items he had taken as proofs?

Further, what information do we have nowadays? Presumably record-keeping has become a much easier task down the ages, and we have a deluge of information to pick from. What examples are there of, say, plants that can no longer pollinate or be pollinated from the aboriginal stock (or an intermediate, for that matter). Surely there are many.

Of course, not being able to reproduce is part of the definition of being a separate species - or at least one of the definitions, depending on who you listen to! (An upcoming post on this is in the writing...)

Questions from reading "God is not Great", by Christopher Hitchens


Even what was first known about the comparatively consoling symmetry of the solar system, with its nonetheless evident tendency to instability and entropy, upset Sir Isaac Newton enough to make him propose that god intervened every now and then to put the orbits back on an even keel. This exposed him to teasing from Leibniz, who asked why god couldn't have got it right the first time.
I'm curious where this account comes from. I have looked at various quotes and stories concerning the various Newton-Leibniz (and Newton-Hooke) arguments, but nothing about this particular item has surfaced...