Never mind – you can have this point in your favour so we can move on to the real meat and potatoes of deleterious/lethal mutations.
Why, thank you kindly for your generosity.
That was only a little sarcastic. While I'm glad that you're smart enough to realize that not all points are worth fighting over, it is a little annoying to have you only grant something because you want to focus on other points. But nevermind that. I'm not all that annoyed, because I know that fecundity is a complicated subject, and while I do have a basic understanding of it, I don't understand it nearly as well as I do evolutionary theory.
I never said you did say that. I said it myself by way of explanation. Please look at what I said again. If a population is exposed to nuclear radiation (causes mutations – many lethal) they don’t respond by having more babies.
Look, you missed my point again. My point is that fecundity increases partially based on if a higher percentage of a population's offspring dies, especially over multiple years, especially if food sources remain steady. It doesn't matter why they die - whether it's due to predators, disease, lethal mutations, or other things. Life appears to respond to death with the urge to create more life.
In this case, nuclear radiation … Firstly, neither the population gene pool nor the individuals know (without scientific investigation – an unnatural intervention) when gametes are dying and defective – but they might find it harder to conceive. Secondly, if they do conceive, the rate of spontaneous miscarriages will probably be higher. They might try again and again before success, and more of the kids might die before they in turn reach reproductive age – but in many cases kids will die too late for the parents to compensate by trying again. All these factors cause a marked decrease in realised fecundity:
Oh, you're just talking about human reproduction? Next time, specify that. I was talking about animal reproduction in general and the effects on generational levels of organisms.
So Jaimehlers, the evidence says you are dead wrong – fecundity in the Ukraine has done exactly the opposite to what you predicted or expected
The Chernobyl disaster was only a single generation ago, though - what was it, 1986? There simply hasn't been time for the increased likelihood of offspring deaths to have the effects I predicted on fecundity. Give it a generation or two - basically, enough time for the surviving children to come to sexual maturity and start reproducing themselves, and you'd see something more akin to the way humans dealt with the likelihood of a child's death for most of history. You have to remember, the child mortality rate was much higher historically than it is today, and the response was to have more children. In England during the 1600s
, for example, the infant mortality rate (children dead within 1 year) was almost 15%. When you factor in other childhood deaths, 30% of all children in England died before they turned 15. So the average birthrate was one child every two years - a much higher rate of fecundity than the one that those Ukranians you referred to in that study undoubtedly had, and even have today.
Before I celebrate a debating victory I have to ask if the Ukraine result supports me? Does it? Maybe a slight victory only – because if it ever is rectified it'll take the usual fecundity in unaffected parts of the greater world population to, over time, assist in recolonising the Ukraine gene pool with good genes while Ukraine gene pool is gradually purged of all the crap mutations from radiation – purging by death of gametes, zygotes, foetuses, babies, toddlers, teenagers and young adults, as well as fertility problems with many of the surviving adults. Some surviving Ukrainians will migrate elsewhere and contaminate other gene pools - but fecundity will not increase there in "response" either. Any bad mutations will, however, continue purging themselves.
Granted, but you're missing a much more serious point, one I stated early on - and thus why you should not celebrate victory just yet. Let's say, for the sake of argument, that the Ukranians represented all of humanity rather than a relatively small proportion. All of the lethal mutations purge themselves from the population, granted, but there's a much higher number of them than normal. Enough so that nowhere near enough children are born to sustain the population - as the trends from your study show, with the population declining by more than 10% over the next 15 years. That kind of death rate is enough to seriously threaten the survival of the species as a whole if it keeps up. And, worse, fecundity isn't enough to fix the problem on its own, because so many of the gametes end up carrying lethal mutations.
As I said, "if the percentage of lethal genetic mutations was sufficiently high, then predation and disease would be a much more deadly threat to the survival of a species than they actually are." And while I was talking about animals in general rather than humans, the general statement holds true. When most offspring don't survive till sexual maturity, then other causes of death are magnified and become a much more serious threat than they would in a population with a high enough birthrate.
This is the first leg my argument stands on – deleterious/lethal mutations do fuck things up a lot but are purged and replaced through fecundity, so that in evolutionary time you‘ll be hard pressed to know the bad mutations existed unless science keeps a record for you.
But it illustrates what I was originally referring to as well. If the rate of mutation is high enough, you have a serious problem on your hands, one that might 'fix' itself by eventually purging the whole species. It doesn't even have to cause the species to go extinct by itself, it just has to drop the population low enough. Then you're on the razor's edge of survival, all because of a high rate of lethal genetic mutations.
My opinion is that this is one of the least deployed but most powerful concepts we have when creationists and sneaky IC proponents tell us that bad mutations, if left to their own devices without godly intervention, will only destroy genetic information. Bad genes destroy themselves. They don’t accumulate in a population anything like the goddidit brigade so wish they did.
Which is well and good, unless the rate of lethal mutations is too high, for the reasons I mentioned above. That's why I don't think the rate at which lethal mutations happen is particularly high in general.
That was Part One. Next part in a day or two - sorry I’m very busy at the moment. But I can assure the next part will be full of exciting learnings about how prevalent deleterious/lethal mutations are! And why the high rate of bad mutations doesn’t matter either. And complexity can actually increase as a direct result of random mutations breaking things
Well, I'll be interested in reading it. I'm always open to learning new things. But I hope you learned something as well from what I brought up here.