by IW 25 Replies latest jw friends
Does the theory of evolution supply the genetic answer to the self-sacrificing nature of many animal parents as well as that of many men and women in general?
When a man or woman risks their life to help someone in danger is their response simply a response to the natural processes at work due to evolution's effect on their DNA? If so, can this self-sacrificing gene be isolated?
We are our genes, we are told.
IW
Look up anything with Hamilton's Rule, such as: http://www.brembs.net/hamilton/
Yes. Evolution selects lineages that promote the continued existence of their kind.
Self-sacrificing behavior is seen throughout the animal world, and as a rule, individuals are much more willing to take risks for closely related young. Many animals will give food to their nieces and nephews, but dote most loyally on their own offspring, which is what evolution would predict. A certain spider is even willing to kill himself after mating by sacrificing himself to the female, as this behavior usually satiates the female so that no further sex occurs, thereby raising the odds that the male's genes (and not someone else's) will live on.
Of course, the spider (and indeed the other self-sacrificers besides humans and perhaps other advanced primates) clearly have no conscious understanding of the reasons for their activity. But in these cases the activity was more successful at continuing the existence of the lineage than competing non-self-sacrificing behavior, and so it was reinforced.
SNG
Intelligence and especially civilization are anti-evolutionary forces. Evolution is only concerned with reproduction. Think of how much longer old people stay alive now, to no reproductive purpose--civilization is required for this. Think of how many people with congenital problems who would otherwise have died and not passed their genes on now survive and breed because of modern medicine.
For intelligent species evolution stops or changes drastically--it must--when civilization and advanced technology take over. The next hundred years, provided that we don't wipe ourselves out, will be very interesting indeed.
A certain spider is even willing to kill himself after mating by sacrificing himself to the female, as this behavior usually satiates the female so that no further sex occurs, thereby raising the odds that the male's genes (and not someone else's) will live on.
Well, and more critically, provides nourishment for her young. That's a huge advantage for seeing to it that his genes are passed on to viable descendents.
under_believer,
Intelligence and especially civilization are anti-evolutionary forces. Evolution is only concerned with reproduction. Think of how much longer old people stay alive now, to no reproductive purpose--civilization is required for this. Think of how many people with congenital problems who would otherwise have died and not passed their genes on now survive and breed because of modern medicine.
Intelligence, technology, and civilization are not anti-evolutionary at all. They simply change the selective pressure. In a technologically evolved society, people who in other environments would be selected out live on. But this is no different than, for example, fish that begin to live in underwater caves. Normally, blind fish would be disadvantaged and immediately be selected out, but in the new environment it is no longer an issue so selective pressure now works on other fronts. Remember, evolution has no inherent goal. Environments change, and selective pressure necessarily changes too.
SNG
Think of how much longer old people stay alive now, to no reproductive purpose
No reproductive purpose but still an evolutionary purpose. For example looking after their grandkids while the parents work to secure the grandkids a better education etc. This can give the next generation a big advantage.
For intelligent species evolution stops or changes drastically
I would agree that it changes, and focuses more on intelligence than physical strength. But evolution can never stop until reproduction stops, or the environment stops changing.
The next hundred years, provided that we don't wipe ourselves out, will be very interesting indeed.
I see man taking some control over his own evolution with genetic technologies. You're right very interesting. Will make or break the human species imho (without trying to be overly dramatic).
I acknowledge that I misspoke. What I was trying to convey is that technology, intelligence, and civilization affect evolution in ways that are unprecedented in observable history or in any existing theory of natural selection. I don't think that's a controversial statement.
I'd like to add that since technology gives every indication of allowing humans to take control of their (and other species) genes, thereby superseding mutation as the primary source of spontaneous, non-selectional changes, the evolution equation really does change greatly.
hey, no worries mate (in aussie drawl) no nothing controversial there
I remember reading a post back in the archives somewhere with the question about whether evolution has stopped because man hasnt changed for a couple of thousand years
I dont think you'll be able to say that in a thousand years time
cheers
pak
Does the theory of evolution supply the genetic answer to the self-sacrificing nature of many animal parents as well as that of many men and women in general?
Yes; a behaviour exhibited in a parent that increases the chance of its young surviving over and above that of an otherwise identical organism NOT exhibiting that behaviour will eventually come to dominate a population; in less than 200 generations even a 5% increased chance of the young surviving will spread to an entire population.
In some areas of life we are told to follow the money to find out what's going on; in evolution we follow the genes. It doesn't matter what nasty consequences the bahaviour has on the parent; it only matters if that behaviour increases its chance of young surviving.
Take the suicidal male spider; it does that as the male spiders that did that were more likely to fertilise females and have young bearing those genes, as that's what drives evolution along; selection. The fact that is dies is irrelevent in this context as it is the very action which kills it which leads to it having a greater genetic contribution to the next generation.
Of course, such actions are not neccesarily life threatening.
Take the lapwing (ground nesting bird that does a fake broken wing display to attract predators getting close to its eggs or chicks); it's behaviour surely increases it's young survival chance, but also rarely gives real risk to the parent
When a man or woman risks their life to help someone in danger is their response simply a response to the natural processes at work due to evolution's effect on their DNA? If so, can this self-sacrificing gene be isolated?
For a start that no such gene as a 'self sacrificing gene'. That would require a genetic complex to reason. There are behaviours caused by genetic make-up which lead to greater reproductive success, but it's not knowlingly. It's not like the lapwing 'thinks', "ah, this'll fool the fox, this technique works really well and has done for years". It has a behaviour that makes it act like that under certain stimulus, because those exhibiting the same behaviour before it had more chicks survive to breed than those who didn't, so today's lapwing is very likely to carry those same genes as a descendent of those previous lapwings.
Humans are different. We are knowing, and sometimes people do commit altruistic acts.
For example; a guy walking through a foreign town (no relatives), who without real concious thought runs in front of a car and throws a toddler to safety whilst losing his own life.
However, often seeming "altruism" has internal rewards; like feeling good about doing something altruistic, or doing it because it conforms to some internal belief set. Other times it occurs because it is a social expectation with adverse concequences if it's not carried out; not done for benefit but done to avoid criticism or disadvantagement.
Of course, parents will often risk their live or suffer for their kids as they have a drive to do so as - like I said at the outset - we have to follow the genes to figure out what it going on, and this is one example where obviously instinct might overcome intellect.
But normally risk is a calculated with a cost/beenfit equation for the one carrying it out even if this is abstract intangible and internalised.
We are our genes, we are told.
Or is it our genes who are us?
What I was trying to convey is that technology, intelligence, and civilization affect evolution in ways that are unprecedented in observable history or in any existing theory of natural selection. I don't think that's a controversial statement.
If we define evolution as;
A process whereby those members of a species displaying behaviour or characteristics (due to their genetic make-up) that increases the chance of producing offspring that survive to breed will thus pass those very genes on to their offspring and thus increase the penetration of those genes into the organism's genome, resulting in greater numbers of that species carrying that gene and leading to either a change in the species over time to one where that trait is universal, or the differentiation of one species into two or more species with varying traits if barriers to movement allow the original gene-pool of the species to be divided into several non-interbreeding gene-pools
... then all humans have done recently is come-up with a very extended phenotype... beavers have dams, that's their 'extended phenotype'. We have all the shit humans have made. Our extended phenotype has introduced some selection factors whilst reducing others;
You don't need as robust a constitution to survive childhood and adulthood due to modern medicine and hygene; selection for a strong constitution is reduced.
You can survive even if you are very short-sighted due to eye-sight correction; selection against myopia reduced.
Thousands of new chemicals are now in the environment than historically; some will have problems surviving or breeding with this pollution, others will be fine and their genes will be selected for.
We can now re-write or edit our own geneotype and can essentailly play with evolution.
So, in some ways evolutionary pressure is reduced, in other sometimes new ways it is increased. But it is still there.
