Problems with this “survival of the fittest” metaphor for natural selection include
This is not to say “survival of the fittest” is not an apt and useful metaphor, only that it is an approximate, not an absolutely accurate, one.
- That what trait is or will be effectively “strong” or “weak” is hard to determine. For example:
- Heritable diseases may provide critical resistance to future environmental or disease pathogens
- Disable individuals may have a beneficial affect on society by filling peculiar social roles, or promoting beneficial social behaviors such as charity and compassion
- Because the smallest unit of that which can live to reproduce or die without reproducing is the individual organism, not individual heritable traits, beneficial traits may be culled and detrimental ones perpetuated because they are present in an individual with other survival-impacting traits
- Sometime the fit are just unlucky, and die, while the less fit are lucky, and survive
True, true. But aside from nitpicking, what we are doing when we go to every conceivable effort to ensure the survival of each and every
newborn baby, as happens in each and every maternity ward in the developed world, regardless of the baby's genetic benefits or drawbacks, something big is happening. We have now effectively removed humans from the set of animals who, from the very start, is expected to survive based on genetic fitness alone. Plenty newborn humans spend their first years in oxygen tents whilst their malfunctioning lungs are repaired. They were not supposed to live past day 1. The point whether any particular set of genetic variants is "good" or "bad" is moot - it doesn't matter at all. What does matter, is that we've opened the evolutionary filters through technology - everything
This claim presupposes that
- Electric lights and other night-vision aids actually have tamed the night environment
If you mean the area of the night environment occupied by humans, then yes. But its not a presupposition, it's a fact. Illumination is only a light-switch away. If there's a part of the nighttime environment not
claimed and tamed by humans, you merely take a portable torch or lamp with you. This should be, pardon the pun, glaringly
Every possible enhancement of visual perception can be accomplished with better illumination, optical devices, image-enhancement software, etc.
While I’m transhumanist enough to imagine, and even wish for, a future in which artificial visual systems render our present fleshy, nervy orbs obsolete in every way, I realist enough to expect this may be a long time coming, or may never come.As with vision, this presupposes that our mastery of our environment is effectively absolute. Though I share the dream of this occurring, I don’t believe that it has, by a long shot, at present.
I don't think you understand what I was trying to say. Technological mastery of the night environment, for instance, does not imply a kind of a technological implant or anything genetic to occur. A simple torch in the hand is mastery of the environment enough. It's a technological invention that negates the need for any specific biological developments or adaptations to do the job. Someone who can see perfectly well in the dark has no, absolutely no
reproductive advantage over someone who can flip a light switch. So, there is no evolutionary impetus for his perfect night-sight to be selected for
. A thousand generations down the line, him and his buddy who could merely flip light switches, have spread their genes through the gene pool roughly equally - and by doing so, by allowing each and every nitwit, dimwit, genius, retard, savant, you-name-it, to breed like we're currently doing, their respective genetic oddities have become so diluted as to not become expressed.
Though our tool use is of tremendous benefit to us – I’ll go so far as to believe they set us apart from other animals more than any other major collection of traits, as I don’t see dolphins or termites landing spaceships on Mars – artifice is not at present the best solution to every environmental challenge, and in some situations, is actually a detriment. For example, labor-saving devices are a major cause of physical under-exercise and obesity, a major factor leading to untimely death.
Nope. Sorry - the example you named above, leads to obesity and untimely death - true. But not early enough. It kills too late. By the time Billy Bob will die of atherosclerosis in his mid-forties, he already has five kids. And it is also a statistical fact that the unemployed generally breed more than the employed and more well-off. And, of course, MedicAid (or whatever your country's version thereof might be) will go all-out to save the lives of each and every single one of his kids' lives with public tax money. It's like a termite colony out of control.
Dwellings and conveyances limit our contact with the dirtiest parts of our environment, which appears to cause immune system malformation resulting in potentially fertility and life-threatening disorders.
Exactly. And that's my whole point. And through technology, we invent respirators (ala Michael Jackson) and air filters and convert our homes into hermetically sealed units so that no ill can befall us inside. We have tamed the environment, and no amount of allergies or sniffles or any general "unfitness" in the classical sense will make us breed less. Any new discomfort will be shunned into some dark corner by some New! Improved! technology.
A point: evolution is not due entirely or even mostly to the acquisition of random genetic mutation, but in the large to acquiring old genes in different combinations via ordinary sexual reproduction.
True - and combinations thereof might be detrimental or beneficial. The point is, whatever good (or bad) might come out of a random genetic coupling between two individuals is nullified in the maternity ward and general medical care for the rest of the new individual's life. And if he by some change acquired a beneficial trait, there is nothing in our approach to the whole matter that would raise his chances of reproduction any higher than the next individual (who was actually destined to die a few days after birth from a genetic heart defect that was picked up in time and operated upon.)
Again, I agree, tools help, tremendously. However, purely biological advantages are also advantageous.
Well, I agree with you fully, if only us humans weren't so hell-bent on our technology! Because, by using our technology, we have levelled the playing field between those biologically advantaged and biologically disadvantaged. They have equal opportunity to procreate. With the nett effect that any genetic advantage the first individual might have had over the second, will be diluted into oblivion in the gene pool. His
kids will find no benefit from their genetic inheritance, because, like their father, they are pitched into the dating game on an equal footing with all the rest - due to the technology in the maternity ward and general medical care thereafter. So, once again, technology is the big equaliser - and nullifies any genetig advantage.
All the present-day technology in the world is not enough to give selective advantage to a person with many heritable biological disabilities over a more biologically fit person
a bit of a jump, in my book, at least.
] – especially if the disabilities and fitness are related to fertility.
Fertility treatment is one of the biggest causes of multiple births in not only the US, but the World!
So - you have a father and a mother, who for some reason cannot have kids. Then, they take some of the father's sperm and some of the mother's eggs and do their thing in a test-tube. Let's say the sperm can't swim, for some reason. Then, they take the fertilised eggs and plant them into the womb. And, because the failure rate for individual sessions is high, they implant muliple fertilised eggs. With the nett result that this father and mother, who are explicitly unfit for procreation (if they weren't, they would've) end up getting triplets, quadruplets, or, god help us all, eight - like the infamous octomom. Which means the genes that originally caused the fertility problems will spread even faster than what a gene would that was inherited the normal way, with only one live birth. And don't pounce on the "failure rate for individual sessions is high" bit, because those that can afford fertility treatment normally go back if the first round is unsuccessful. Persistant lot, those genetically unfit buggers!
But, because of the vast size of our gene pool, and our insistence to save every baby born, whatever gene was inherited (evolution) would dilute away. (Which brings us back to the Shark scenario, and our mastery of our environment that allows
that very same dilution...)
Another explanation for why people don’t accept that our mastery of our environment has removed us from the set of animals subject to evolutionary adaptation to environmental change is related to their perception of cause.
Most people, I think, agree that human planning, tool use, and other technology has and is affording us tremendous advantages we would not have if we lived much like other animals. However, our ability to think, communicate, and build appears to me and, I think, many others, to have been caused by biological evolution, rather than our biological evolution having been caused by it. The truth of how much of our continuing success is due to our social abilities and artifice, vs. how much is due to our biology, vs. how much is due to luck, is, I think, moot (in the old sense of the word).
The "mastery" I claim we have over our environment is not old enough to have really influenced our obvious genetic constitution very much. A Roman born with a genetic heart defect would have died in his mother's arms. Today, it's a completely different story. But due to our technology, today people with no business being alive genetically are roaming the streets looking to procreate on an even footing with those that are genetically sound. And surely that will have the biggest impact on our genetic development in the future - and it's all thanks to our technology. Carrying on like this, pretty soon not a single baby in the developed world will be able to live through its first 24 hours without vast and comprehensive medical assistance. Yes, technology once again.