Genetic Inheritance Patterns

[Agent Smith]

It's been a while since I used my ancient biology files. I hope they aren't so outdated that what I'm about to post and what I'm about to ask isn't just plain nonsense. Well, here goes ...   

 

Genes come in pairs, for every trait there is, let's say for trait T, there's a recessive gene a and a dominant gene A. Offspring inherit combinations of these genes from their parents. Using a Punit square we can see that we have for trait T, 4 possible genotypes: AA, Aa, aA, aa. I recall being taught that dominant genes fully express themselves in the offspring with genotypes AA, Aa, aA. That's 3 out of 4 children that'll manifest the phenotype encoded by the dominant gene, here A. In only 1 out of 4 children will the recessive gene express itself. 

My query is is this safe/good for evolution? What's the evolutionary advantage of this type of inheritance pattern? My own guess is dominant genes have passed the test of natural selection (they have a history of being evolutionarily successful) and so it's better that they're expressed in the offspring, increasing the odds of survival.

The recessive gene (here a) is our backup plan B, a just in case thing, a space for mutation to create novel traits, which might turn out to be a life-saver. This would require mutations to be more frequent in recessive genes than dominant ones. There are downsides though; not all mutations are beneficial. I suggest reading sickle-cell anemia.

[Sarae.the.wannabe.chemist]

Hmm... You bring up an interesting topic. Your knowledge isn't ancient (I suspect) because I was taught this way in 8th grade last year (though our textbooks tend to be pretty outdated themselves, which explains the irrelevant things we "learn" here in America. But that's another topic for another day). I believe this heavily depends on the creature and their binomial nomenclature ranking. Scenario: humans can be either tall or short, depending on their dominant and recessive genes. We don't necessarily NEED to be the former or the latter based on our world today, but that isn't the case for, say giraffes. Giraffes eat tree leaves. Trees are usually very, very tall. So, God made giraffes tall enough to eat from them so that they can survive and have nourishment. If they weren't, then that would be an issue. Trying to find a tree short enough to accomodate their height all the time could take so long that they don't eat at all and die of starvation. So while it isn't entirely safe or dangerous because there are just SOO many different creatures, God does equip those who need certain genetic patterns in their day-to-day life with them.

[exchemist]

8 hours ago, Sarae.the.wannabe.chemist said:

Hmm... You bring up an interesting topic. Your knowledge isn't ancient (I suspect) because I was taught this way in 8th grade last year (though our textbooks tend to be pretty outdated themselves, which explains the irrelevant things we "learn" here in America. But that's another topic for another day). I believe this heavily depends on the creature and their binomial nomenclature ranking. Scenario: humans can be either tall or short, depending on their dominant and recessive genes. We don't necessarily NEED to be the former or the latter based on our world today, but that isn't the case for, say giraffes. Giraffes eat tree leaves. Trees are usually very, very tall. So, God made giraffes tall enough to eat from them so that they can survive and have nourishment. If they weren't, then that would be an issue. Trying to find a tree short enough to accomodate their height all the time could take so long that they don't eat at all and die of starvation. So while it isn't entirely safe or dangerous because there are just SOO many different creatures, God does equip those who need certain genetic patterns in their day-to-day life with them.

Hmm, it is not good science to say simply that "God made" individual creatures the way they are, as that does not provide a natural explanation of how they came to be the way they are.

Science is all about accounting for what we observe in nature  in terms of natural processes, not supernatural intervention. A religious believer is of course free to  believe God created nature and upholds its processes via the laws of nature. But science shows us it is the operation of these laws that has led to the forms of life we observe today via evolution, which is one of the best supported theories in science.  

Invoking supernatural intervention as an explanation is in fact a science stopper, as it discourages the search for natural mechanisms. We just say "God did it", case closed, and go on none the wiser than medieval people who thought earthquakes, or plagues, were "acts of God" with no natural explanation.

So by all means continue with your religious belief, but you should start moving on to a more adult, educated version of it that accommodates science. That is what the mainstream Christian denominations have done.  If you don't, you will find yourself forced to make an unnecessary choice between science and religion, which risks leaving you intellectually impoverished. 

Edited Sunday at 10:22 AM by exchemist

[Sarae.the.wannabe.chemist]

@exchemist Understood. I am Christian actually, so I believe science is the reaction to God's words, and when we study it, we're studying God's choices of why things are the way they are. I hope I'm not misinterpreting you here, but when you say more "adult" version, do you mean what everyone else says about God + science? Please feel free to correct me if I'm wrong. 

[exchemist]

1 hour ago, Sarae.the.wannabe.chemist said:

@exchemist Understood. I am Christian actually, so I believe science is the reaction to God's words, and when we study it, we're studying God's choices of why things are the way they are. I hope I'm not misinterpreting you here, but when you say more "adult" version, do you mean what everyone else says about God + science? Please feel free to correct me if I'm wrong. 

Yes I gathered that. What I mean is what I said about God working through natural processes, rather than overruling them by supernatural power. Evolution is a classic example. What you wrote about God “making a giraffe tall enough” rather suggested some sort of intervention, rather than allowing evolution to take its natural course. Such a belief would be incompatible with the scientific evidence. OK as a bible story for children perhaps, but no good once you start learning about fossils, dinosaurs etc. Whereas what I called the “adult” mainstream Christian view would be that God works through evolution following the laws of nature, which can perhaps be seen as His laws. 
 

I’m not sure what you understand by what everyone else says about God and science. It seems to me different people say very different things about that. What I have described as a mainstream view would not be shared, for instance, by creationists in the US Bible Belt, who are forced to think science is all wrong because they insist on taking every word of the Old Testament literally.

[Sarae.the.wannabe.chemist]

@exchemist Right. Science is definitely not all wrong. I understand.

[exchemist]

1 minute ago, Sarae.the.wannabe.chemist said:

@exchemist Right. Science is definitely not all wrong. I understand.

Yeah I just get a bit worried with some young people because there is this damaging idea around that religion and science are in conflict. It was all started by an American academic at the turn of the previous century called Andrew Dickson White who developed the so-called "conflict thesis": https://en.wikipedia.org/wiki/Conflict_thesis. It is a discredited idea but is nonetheless quite widespread in popular culture.  Religion has generally been supportive of science, about the only historical exception being the Galileo affair. Anyway, as you mentioned God I became anxious that you should never feel you have to make a choice between the two, that's all. 🙂  

[TheVat]

20 minutes ago, exchemist said:

Religion has generally been supportive of science, about the only historical exception being the Galileo affair.

And that nastiness with Giordano Bruno. And Vesalius got a lot of flack.  But yes, that supportive stance seems mostly true of modern mainstream sects.  (fundies excepted, as you note)   I'm always happy to see the car decals we have in the US that show "Darwin" printed inside a stylized fish outline (for those not familiar, the fish is a common Christian symbol - so the decal is saying "our Christian belief and the science of evolution are compatible")

Many noted scientists have expressed that their science and their spiritual beliefs occupy different domains of knowing - those domains don't tend to intersect, so they don't conflict.  I don't point a PET scanner or fMRI at my head to meditate, or otherwise tap into whatever intuitions I have on the metaphysical.  It would like writing a poem by pushing around alphabet blocks.

 

[exchemist]

26 minutes ago, TheVat said:

And that nastiness with Giordano Bruno. And Vesalius got a lot of flack.  But yes, that supportive stance seems mostly true of modern mainstream sects.  (fundies excepted, as you note)   I'm always happy to see the car decals we have in the US that show "Darwin" printed inside a stylized fish outline (for those not familiar, the fish is a common Christian symbol - so the decal is saying "our Christian belief and the science of evolution are compatible")

Many noted scientists have expressed that their science and their spiritual beliefs occupy different domains of knowing - those domains don't tend to intersect, so they don't conflict.  I don't point a PET scanner or fMRI at my head to meditate, or otherwise tap into whatever intuitions I have on the metaphysical.  It would like writing a poem by pushing around alphabet blocks.

 

Indeed. And I don’t want to lose a teenager’s interest in science due to any perceived conflict with the religion in which they have been brought up.

[Sarae.the.wannabe.chemist]

@exchemist @TheVat All excellent points, guys! There were, in fact, scientists whose faith in Christ never conflicted with science. Issac Newton is one of them. Religion is a soul's way of asking why and science answers.

Edited Sunday at 11:05 PM by Sarae.the.wannabe.chemist