Output Stream of Consciousness

They are normally fairly timely with moderating comments over on the Expelled! movie blog but, unusually, the moderation has been out of commission there for over a week and a half so far.

Now it could be that there is just one guy and he went on holiday, but in the absence of any news in this regard, I wish to save my one post from moderation purgatory, and post it here instead...

One of the users was posting on the blog, complaining that nobody had answered his seven questions:

Now, I’m going to repeat a few questions everyone seems very comfortable leaving alone. I posted them earlier and it’s just a few of many I could ask you.

Now, he claims to be a "molecular biologist in the medical research area", which makes me wonder what classes he skipped... or where, indeed, he learned his biology, but fair enough :)

I answered him, but the answer is held, at this time, in moderation limbo.

So here it is, albeit in my obscure blog in a corner of the internet :)

Paul said:

1)If bone comes from the hardening of cartiledge, then how come cartilaginous fish are more highly developed and younger than bony fish? How come we can find, so called archaic fossils or fish like the coelacanth and it hasn’t ever changed in form?

Hmmm? Chrondichthyes (rays, skates, sharks) and Teleostomi (eventually becoming tetrapods and the bony fish we know today) split from each other. How would that make the cartilaginous fish “more highly developed and younger”?

Also, referring to “the coelacanth” as having never changed is incorrect. For one, the fossil record has coelacanths, emphasis on the plural, including genera in the same family as the modern coelacanth like Macropoma, and others that are in different families like Wimania. The modern coelacanths are of the genus Latimeria.

2)When all the necessary adaptations were taking place from one organism to another, how did the animal survive? And what would have formed first in such sequences seeing as you need veins for blood but blood for veins in our circulatory system, stomach acid for digestion yet the proper stomach to hold the acid, etc.

This is better than the “3/4 of a heart” question I’ve seen from others :)

The “intermediates” would have had to survive on their own terms. There is no evolutionary hypothesis for preserving the lives of creatures just so they can survive while their lineage is adapting to an environment. Some of these are still open questions, others have had research done on them. The two you have posed are interesting. I don’t have a lot of time to look things up at the moment, but clues to these questions can be found generally in the variety of systems in nature and the relations of the tissues in question. Veins are related to skin, for example, and insects have an open circulatory system, but which is only used for food and waste, but not generally not oxygen carriage.

3)How is it possible by random chance that two organisms, both fully developed and opposite sex were in the same place at exactly the same time in order to propagate? Also, why on earth for two sexes anyways? It’s much more efficient for assexual reproduction according to survival of the fittest and if single celled bacteria propagate like this, and we are a result of that, then why change that?

Asexual reproduction may be more ‘efficient’, but sexual reproduction is a lot better at sharing and shuffling genes, as well as making bad genes more survivable (that is the essence of recessive genes). Meiosis is the sole requirement for sexual reproduction and does not require opposite sexes. Asymmetry in the sexes does help out organisms that have trouble “finding” one another. Plant pollen is a pretty spectacular example - millions upon millions of pollen grains help find the sessile ovaries by sheer numbers.

4) Why have feelings? They make survival much more difficult.

How do they make survival more difficult? Our Vulcan friend was wrong. Without feelings, you have no actions. We know some of this even medically in part from observations of lesions in the limbic system in (non-experimental! :) humans and experimental animals. If hunger provided no emotional reaction, how would you ever survive long enough to be able to cerebrally observe that food is a requirement?

...or did you have something else in mind?

5) In order for a mutation to be accepted and survive, it has to be beneficial. However, even the smallest of mutations in the animal kingdom causes the parents to kill the child (look at monkeys or runts of the litter). So how did all the mutations survive from then until now?

Truth be told, runts are usually just runts due to placement in the uterus. With a bad head start, animal parents with limited resources make their investments. All of the children carry mutations. Most of them don’t matter. Many of them involve matters of degree.

I’m unaffected by caffeine or sedatives. Mutation (at least genealogically)? Probably. Fatal? Not hardly :)

7)Can you give me one example where random genetic mutation or drift leads to an INCREASE in genetic information? (It’s always a loss or condensing in organisms we can see as far as I know, unless you can tell me different)

Well, I could quote you nylonase bacteria or the lizards on the atoll that formed a cecum in 37 years, but it really comes down to what metric you are using for "information". After all, total randomness in a gene would contain a lot of Shannon information. It could even be kept intact in a test tube.

I am guessing that you are using some intuitive notion of "information that keeps the creature alive", but such a thing is not, to my knowledge, rigorously defined anywhere. Whatever metric that is, it is not interchangeable with the pure mathematical notion of information, which is where some of the communication breakdown occurs.

Is this what you were looking for?