abciximab

Hmm, *if* that is proved to be a cause-effect thing rather than a pure association, it could bring up a very interesting purpose for homosexuality. I've always wondered if homosexuality is intended to be a form of population control, and whether our population's recent increase in acceptance of homosexuality relates indirectly to the fact that we are quickly becoming overpopulated and realize that we don't need everyone having kids anymore. Maybe the hormonal feedback that causes later born sons to be homosexual is an intrinsic population control method; attenuating the number of sexually viable men that a mother produces. If they talk about this in the article sorry for being redundant, I didn't read it because I'm in a bit of a hurry... Do the authors mention whether having girls in between resets, reduces, or doesn't affect this effect?

Only mature red blood cells lose their nucleus; the various types of white blood cells (neutrophils, monocytes, eosinophils, lymphocytes, etc) keep their nucleus for their entire life and are high enough in number to have enough DNA to ID a person as psynapse said...

The moths were not silver initially because the trees were initially the white birch trees that we are familiar with. It's not that easy to see a silvery white moth on this, so they were initially camoflauged. Then industrial soot started depositing on these same birch trees, and silvery moths weren't all that camo anymore against a black background. They stood out, and were quickly eaten up. If they happened to have a darker kid, though, it would survive to pass its dark genes on because the hawks wouldn't see it as fast. This would continue and over many generations the standard colour of the moths was black because that was (almost) the only gene left in the gene pool. Your example about the plant and the berry is one of co-evolution; I thought I'd give you the official name because many books and essays have been written on it and it might interest you to read some. Generally co-evolution occurs between species when there is either mutual benefit or an "arms war" in which one or both change to be able to better help or hurt each other. One thing I always try to remember is that there is no intention, force, desire, will, or anything else 'directing' evolution. It is all just a direct response to the ecosystem that makes certain members of a species more likely to be killed. By being killed before having kids, they don't get to pass on their genes. Thus, the right colour wasn't "chosen" for the butterfly eggs, and in the case of the industrial moths there was no choice of when to change colour. All just response to environment. In the case of the plant and butterfly, I'm going to assume that the plant had berries in the first place, because many do (it's how they spread their seed), but let's say they were large and red, not small and yellow like the butterfly eggs. Genes for colour are often determined by varying degrees of expression of a few colours that blend to make the colour we know. Now, the butterfly starts landing on the plant and laying eggs - but they are yellow and small, not red and big. Regardless, other animals enjoy eating eggs because they provide nutrition. So animals start eating these yellow eggs on the plant, which is killing off the butterfly's eggs. By chance, though, once plant may mutate to make a batch of berries that is very unusually small for that species, and perhaps a bit of a lighter red. The butterfly continues laying its eggs on, but when predators come to eat their eggs, some colourblind species might be fooled into thinking the berries are eggs, and eat them instead! This is awesome for both the plant and the buttefly, because: 1) Plants want their berries to be eaten. The whole reason berries taste good is so creatures eat them and disperse the seeds inside. 2) The butterfly doesn't want its eggs to be eaten. It means having fewer children. So by having other animals mistaken the eggs for the berries and the berries for the eggs, that batch of berries and that batch of eggs is able to better pass its genes on, while the larger redder berries don't get eaten as much (thus don't pass on their genes) because other animals don't think they are butterfly eggs which are more appetizing. So the genes that were involved in chance mutating the berries to be smaller get passed on and survive very well, and this happens again and again - when there is some mutation in either the eggs or the berries that makes them look more similar to each other, it will be preserved not because of any sort of design, but those genes survive the best, and eventually they will converge in shape and pigment to look exactly the same. I hope this helps; these kinds of things are better explained in conversation but I hope you get the idea. Just remember that it's not force, will, or design, merely preservation of random genetic mutations because those members of the species survived a bit longer to pass genes on.

^ what he said in addition, it might be beneficial to know that dopamine is elevated in the brains of people experiencing pleasure, so dopamine receptors in the nucleus accumbens (pleasure center) of your brain could be classified as "pleasure receptors". Not all dopamine receptors are for pleasure though (they are also on the kidney and heart and other parts of the brain, and these have completely different functions.)

there is also St. John's Wort which has apparently been shown to be as effective as certiain SSRIs (sertraline, fluoxetine) for *mild* depression, (1)with fewer side effects, BUT although it is available over-the-counter it interacts with many drugs INCLUDING SSRIs like Celexa so do not just go and use it without consulting your doctor. Perhaps next time you see your doc ask about SJW. Some of its effect may be placebo, but that's also the case for SSRIs often which is why it is hard to design a study that is truly conclusive. (1) http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=12053635&query_hl=5&itool=pubmed_docsum

(repost)

Interesting... if viruses were ever produced by living forms, though, you would think they'd have some beneficial purpose. Are there any cases of species infection with a virus that is good? The thing about HIV to remember is that the virus itself does not kill a person. AIDS patients generally die from a secondary infection due to things like Pneumonia, Tuberculosis, or Esophagitis. The reason they get these infections is because the virus manages to destroy our immune cells - lymphocytes and macrophages - and we cannot defend ourselves against these normally treatable pathogens. So what HIV does is just insert DNA into our immune cells that says "replicate me!" but the cells replicate too many copies and just explode and die. From an evolutionary success standpoint, HIV is actually a "stupid" virus. As the guy in the above study said, "you need to have a cell to even obtain a virus." By biting the hand that feeds it, HIV and any lethal virus is killing itself off as it kills its host. The harm done by a virus is not in its own defense (like a bacterial toxin is), it's a very unintentional side effect. My point: SIV being inocuous in monkeys and harmful in humans is NOT a defense from the monkey to keep humans away, just a mere difference in the species' reaction to the particle. In simians the virus does not snowball in replication so fast that the monkey can't produce more immune cells as fast as they are being destroyed. My thoughts on viruses are that they are kind of a life-mistake. I don't think they can have too intentional a purpose because of several factors. First of all, they replicate very sloppily. If they were specifically designed for a purpose they would likely have evolved regulations on their replication, in the way highly conserved DNA of all other species is regulated if it has a useful purpose. Also, they are not really alive. A virus is just DNA or RNA in a shell, that says "make more of me!" AFAIK (please correct me if I'm wrong), viruses are not a major part of any ecosystem as nutrition, commensals, or symbiotes. In other words, if you erased viruses from the world, would any ecosystem fail? That's why I lean to the side that thinks they were possibly an altered take on life in the beginning; a random aggregation of particles that happened to have function without serving a purpose.