Vet My Answer to a Catholic's Question on Evolution

[Mr. Scott]

I warned a new facebook friend who's Catholic that I hoped she didn't mind me disparaging religion. She got around to asking some questions about evolution.

What do you think of my answer/response? Can it be improved? Did I get anything flat wrong?

May I ask a question, please?? This has been bugging me for a long time. I can undersand that creation and evolution works together. It doesn't have to be one or the other--period. If God creates all of us then why do we have to have male/female--sex, for reproduction?? And if there is no God then how did we get here, and why and where was the first person born?? Where can I find these answers??

Yes, I'm happy to answer an honest question. I'll respond to your statements as well as your question.

There's a huge amount of sound, consistent evidence for evolution, but no evidence for creation.

We don't have to have male/female sex for reproduction. There are many creatures that reproduce without male/female mating, and there's incredible variety in nature. Earthworms are hermaphroditic (each individual has both male and female sex organs), some species of fish can change sex at will if the sex ratio is stacked against them, some lizards are only female and give birth to clones without needing to be impregnated, etc. Even bacteria exchange genes with each other, though they don't have male/female specialization.

Every question about nature has an answer in natural selection. Everything about us that is inherited is there because it had a reproductive advantage for an ancestor. Sex helps us because A) It can correct errors in the genetic code, B) It helps mix up our genes to provide opportunities for evolution, and C) It lets us choose mates with traits we admire to combine with our own traits so offspring have a chance of inheriting the good traits of both parents.

Why we are specialized as male or female I need to read up on and refresh on the details of the most recent scholarship on this. Some things like this started as ancient accidents that, over millions of years, became highly refined.

Did you know that, if a woman has had two men in the same cycle, the sperms of the two go to war with each other within the woman, specializing in offense and defense? This is a result of millions of years of refinement. If God had a "mate for life" foundation, then why these elaborate mechanisms to handle multiple mates? The creation assumption has no answers. The evolution assumption answers questions like this one easily.

We got here in tiny steps over 4 billion years. Each tiny step is fairly easy for scientists to understand.

There really was no first person. We evolved from ape-like ancestors in tiny steps. On the other hand, we have a genetic feature that apes don't have. At some time, in one of our ancestors, two ape chromosomes got stuck together making our chromosome #2. We could call him or her the first person, who might have still looked a lot like an ape, for all we know. But you ask "where?" Somewhere in Africa.

Evolution is a huge subject. A lot happened in 4 billion years and it's taking a lot of detective work nail all the details. I love talking about it!

Here's a pretty respectable web site you might want to browse for answers to questions on evolution: http://www.talkorigins.org/origins/faqs-evolution.html

 

[kellyb]

Regarding this:

C) It lets us choose mates with traits we admire to combine with our own traits so offspring have a chance of inheriting the good traits of both parents.

...I'm not so sure people do that.

Re this:

Did you know that, if a woman has had two men in the same cycle, the sperms of the two go to war with each other within the woman, specializing in offense and defense?

You might want to look up the details. I'm pretty sure sperm can't "live" in a woman for weeks or a month.

ETA:

http://opinionator.blogs.nytimes.com/2008/05/13/a-seedy-rivalry/

As I mentioned a moment ago, sperm competition can only happen in humans if a woman has sex with more than one male during the time when she is fertile. This means that she has to have sex with at least two men in the same week. (The exact window of opportunity is the subject of debate; but although the egg is only viable for about 24 hours, sperm can survive in the reproductive tract for at least a few days.)

 

[Delvo]

I can undersand that creation and evolution works together. It doesn't have to be one or the other--period.

That's actually false, but now is probably not the time to point that out.

If God creates all of us then why do we have to have male/female--sex, for reproduction??

Because that's the way God chose to do it. Anything starting with "If God creates" has the same answer. Going with the premise "If we evolved" instead, there can be other answers, and in this case the answer is mainly that we're stuck with some traits that arose extremely long times ago, regardless of whether they are what we (or a god) would now decide should be the case, or whether the apparent "purpose" is even related to the way we look at them now at all.

For example, having an individual's gender set for life as determined by genes without any input from environmental conditions doesn't seem particularly important, because it's appeared a handful of times but in most cases didn't really make much difference in the species that have it compared to those that don't. So what about the two largest and best-known lineages that have it, mammals & birds? The previous way of determining sex was apparently what's still used in reptiles, a response to the temperature at a particular time in fetal development. But animals whose temperatures don't change much can't use that system, and the ancestors of birds & mammals ended up going warm-blooded. So the only thing making this trait matter and become universal in two large groups of species is an incidental interaction with another trait that conferred the real advantages and wasn't at all about reproductive mechanisms.

And if there is no God then how did we get here

"How did we get here" is so vague it's not really even a question. There could be several different actual questions wrapped up in it.

We don't have to have male/female sex for reproduction. There are many creatures that reproduce without male/female mating, and there's incredible variety in nature. Earthworms are hermaphroditic (each individual has both male and female sex organs), some species of fish can change sex at will if the sex ratio is stacked against them, some lizards are only female and give birth to clones without needing to be impregnated, etc. Even bacteria exchange genes with each other, though they don't have male/female specialization.

Good except for "at will"

Every question about nature has an answer in natural selection. Everything about us that is inherited is there because it had a reproductive advantage for an ancestor.

Not necessarily. Some things linger just because they aren't harmful enough to get themselves eliminated.

Did you know that, if a woman has had two men in the same cycle, the sperms of the two go to war with each other within the woman, specializing in offense and defense?... If God had a "mate for life" foundation...

"Sperm wars" in humans are a myth. Some parts of the idea do occur in other species though. But more importantly, if the other person didn't bring up sexual morality first, then you shouldn't (and even if they did there's a good case to be made for just not debating on that subject at all, at least for now). Keep it a matter of science, without distractions like morality. People's thoughts on the former change more easily when that change isn't also hooked to changes in the latter.

 

[smartcooky]

"Sperm wars" in humans are a myth. Some parts of the idea do occur in other species though. But more importantly, if the other person didn't bring up sexual morality first, then you shouldn't (and even if they did there's a good case to be made for just not debating on that subject at all, at least for now). Keep it a matter of science, without distractions like morality. People's thoughts on the former change more easily when that change isn't also hooked to changes in the latter.

Morality is inextricably tied up with modern humanity, especially religion; it actually has nothing whatever to do with evolution or anthropological human history.

I'm sure that when our hominid ancestors roamed that plains of Africa, neither religion nor morality existed. I expect they would have bred and cross bred with multiple partners just like many wild animals do today.

 

[Roboramma]

Every question about nature has an answer in natural selection. Everything about us that is inherited is there because it had a reproductive advantage for an ancestor.

Not true. Not only can neutral traits remain in the gene pool, there are plenty of traits that are simply an effect of other traits that were selected for, but which themselves are not a product of selection.

See http://en.wikipedia.org/wiki/Spandrel_(biology)

In evolutionary biology, a spandrel is a phenotypic characteristic that is a byproduct of the evolution of some other characteristic, rather than a direct product of adaptive selection.

 

[Trakar]

You should probably refer her to good reference books rather than trying to tackle a subject you really don't seem that well versed in yourself. BTW, being Catholic has nothing to do with not understanding evolution, the science has been well and thoroughly taught in Catholic primary and secondary schools (not to mention universities) for at least the last 50+ years.

 

[Mr. Scott]

Every question about nature has an answer in natural selection. Everything about us that is inherited is there because it had a reproductive advantage for an ancestor.

Not true. Not only can neutral traits remain in the gene pool, there are plenty of traits that are simply an effect of other traits that were selected for, but which themselves are not a product of selection.

See http://en.wikipedia.org/wiki/Spandrel_(biology)

Oh, but most if not all spandrels were indeed advantageous to an ancestor. I think that's part of the definition: a trait that was, in a previous manifestation, helpful. Give me example that shows otherwise.

 

[kellyb]

Oh, but most if not all spandrels were indeed advantageous to an ancestor. I think that's part of the definition: a trait that was, in a previous manifestation, helpful. Give me example that shows otherwise.

Epilepsy. Moles and freckles. Depression.

If any mutation does not create a survival disadvantage, there's no reason (other than random genetic chance) that it won't be replicated indefinitely. Survival-neutral traits are just that - neutral.

eta:

http://evolution.berkeley.edu/evosite/evo101/IIIE5aNotadaptation.shtml

Not Everything is an Adaptation

Although living things sport some amazing adaptations, many characteristics of species are not adaptations at all.

It’s tempting to look for adaptative explanations for everything, from the shape of a flower petal, to the way your dog turns in a circle before it lies down to sleep, to your neighbor’s strawberry blond hair. We could make up a “just so” story, but there are other explanations to consider:

The result of history. Why does the base sequence GGC code for the amino acid glycine in a protein, as opposed to some other amino acid? Because that’s the way it happened to start out—and that’s the way we inherited it from our common ancestor. There is nothing special about the relationship between GGC and glycine. It’s just a historical accident that stuck around.

Just a by-product. Why is blood red? It’s a by-product of the chemistry of blood, which causes it to reflect red light. The chemistry of blood may be an adaptation, but blood’s redness is not itself an adaptation.

 

[MikeG]

You should probably refer her to good reference books rather than trying to tackle a subject you really don't seem that well versed in yourself. .......

I think this is actually rather poor advice.

The personal touch can be vital in these things. Infuriating as it is, facts alone won't persuade everyone (the world would be a very different place if they did). People often look at the deliverer of news rather than the news itself, as we very well know from those spreading religion. Religion isn't spread by referring people to books, it is spread by word of mouth. Sometimes, whatever the content, these are the very best tactics.

Part of my approach would have been to instil enthusiasm and wonder for the subject, but not to claim to know all the answers. "Hey, you've got me there. Let's see what the scientists say" is part of the lesson in itself.

Frankly, I think you've done rather a good job so far, but remember, enthusiasm is the number one trait. Make it interesting.......

Mike

 

[Skeptic Ginger]

Morality is inextricably tied up with modern humanity, especially religion; it actually has nothing whatever to do with evolution or anthropological human history.

I'm sure that when our hominid ancestors roamed that plains of Africa, neither religion nor morality existed. I expect they would have bred and cross bred with multiple partners just like many wild animals do today.

Spouting 'facts' that make sense to you but for which you really haven't bothered to look into is a fail.

There is plenty of evidence morality evolved, it has nature and nurture components, and things like a sense of fairness and right and wrong are probably similar to other emotions like being sad or happy.

 

[Skeptic Ginger]

You should probably refer her to good reference books rather than trying to tackle a subject you really don't seem that well versed in yourself. BTW, being Catholic has nothing to do with not understanding evolution, the science has been well and thoroughly taught in Catholic primary and secondary schools (not to mention universities) for at least the last 50+ years.

Oh come on, his answer is more than adequate.

And it doesn't matter what the Pope's degree on evolution is, (which, BTW, Ratzinger walked back a tad from his predecessor), the woman asked some specific questions which she isn't likely to look in a textbook to get the answers to.

Your answer is pretty good, Mr Scott.

I think Roboramma's tweek is important. A lot of evolution theory is misunderstood because people oversimplify the selection process. Random mutations acted upon by natural selection pressures is a better wording, IMO.

According to Planned Parenthood's materials on the rhythm method, sperm can survive up to 5 days in the woman's reproductive tract. My son is testimony to that fact. The ovum takes about 3 days to pass through the tract if implantation does not occur.

 

[Dr. Keith]

Keep it a matter of science, without distractions like morality. People's thoughts on the former change more easily when that change isn't also hooked to changes in the latter.

That is really important and good advice.

Also would agree with the poster pointing out that Catholicism has embraced evolution, so it shouldn't be hard to bring in some Catholic teaching on the subject. In the right context it could help, if it isn't too confusingly worded. I often refer to church teaching when dealing with wooish Catholics because sometimes the church is less outrageous than the believers. Not often, but sometimes.

Pointing out that the well considered opinion of science is consistent with your religion while the crap you are getting on Facebook is not is surely an appeal to authority, but then logical rules don't always win this sort of debate.

 

[Trakar]

That is really important and good advice.

Also would agree with the poster pointing out that Catholicism has embraced evolution, so it shouldn't be hard to bring in some Catholic teaching on the subject. In the right context it could help, if it isn't too confusingly worded. I often refer to church teaching when dealing with wooish Catholics because sometimes the church is less outrageous than the believers. Not often, but sometimes.

Pointing out that the well considered opinion of science is consistent with your religion while the crap you are getting on Facebook is not is surely an appeal to authority, but then logical rules don't always win this sort of debate.

(edit - apologies Dr. Keith, I should have made this clear that I was adding to your comments, not contradicting or necessarily responding to those comments- TS)

Indeed.

It might help to familiarize yourself with the Church's position on this issue before you try to explain things as well, so that you can frame the message in terms that the person in question will find compatible with their religious persuasion.

A couple of references:

http://www.ewtn.com/library/humanity/evolutn.txt

http://www.catholic.org/national/national_story.php?id=18524

(note in this last article, one of the chief vatican scientists corrects a cardinal who has spoken out publically in error and contradiction to Catholic orthodoxy on this subject.)

 

[Hellbound]

Epilepsy. Moles and freckles. Depression.

If any mutation does not create a survival disadvantage, there's no reason (other than random genetic chance) that it won't be replicated indefinitely. Survival-neutral traits are just that - neutral.

Justr an addition to this, even disadvantageous traits may be kept if they are linked to traits that have a good effect. Compare Sickle Cell Anemia vs. Malria for a classic example.

ETA: One thing to keep in mind is that evolution isn't about what's best, but what's better. It isn't trying for perfection, but trying for good enough.

Which is an important point in creation versus evolution, I think. With creation the question is "Why isn't everything perfect?". With evolution the questions becomes "Why would you expect it to be?"

 

[Dr. Keith]

(edit - apologies Dr. Keith, I should have made this clear that I was adding to your comments, not contradicting or necessarily responding to those comments- TS)

Seems clear to me and you went the extra step to find helpful information. Gold Star for adding actionable information to my bloviating!

 

[Dr. Keith]

Which is an important point in creation versus evolution, I think. With creation the question is "Why isn't everything perfect?". With evolution the questions becomes "Why would you expect it to be?"

Excellent point.

 

[Roboramma]

Oh, but most if not all spandrels were indeed advantageous to an ancestor. I think that's part of the definition: a trait that was, in a previous manifestation, helpful. Give me example that shows otherwise.

You seem to be confusing a spandrel with something else. A spandrel is a biproduct of something which was selected for.

Skin colour* might be a simple example: people living at higher latitudes produce less vitamin D because they are exposed to less sunlight. Lower melanin concentration is selected for. But it isn't colour that's being selected for here, it's vitamin D production. We have two phenotypes that are linked through selection: skin colour and vitamin D production. The former is a spandrel.

What's interesting is that spandrels can open up new pathways to evolution: colour could be selected for at this point: perhaps the lighter skin becomes important for camouflage, or makes diseases more visible and is sexually selected, or something else. Note that selection is now acting on a trait distinct from the vitamin D production that was previously selected for.

By the way, I'm only using this is as a simple example, I doubt that the actual evolution in humans was as simple as I am making it out to be in the above.

* In case it isn't clear, by colour I am specifically talking about the skin's appearance in visible light. This is a distinct property to vitamin D production, though they are obviously linked.

 

[Mr. Scott]

You seem to be confusing a spandrel with something else. A spandrel is a biproduct of something which was selected for.

Skin colour* might be a simple example: people living at higher latitudes produce less vitamin D because they are exposed to less sunlight. Lower melanin concentration is selected for. But it isn't colour that's being selected for here, it's vitamin D production. We have two phenotypes that are linked through selection: skin colour and vitamin D production. The former is a spandrel.

What's interesting is that spandrels can open up new pathways to evolution: colour could be selected for at this point: perhaps the lighter skin becomes important for camouflage, or makes diseases more visible and is sexually selected, or something else. Note that selection is now acting on a trait distinct from the vitamin D production that was previously selected for.

By the way, I'm only using this is as a simple example, I doubt that the actual evolution in humans was as simple as I am making it out to be in the above.

* In case it isn't clear, by colour I am specifically talking about the skin's appearance in visible light. This is a distinct property to vitamin D production, though they are obviously linked.

It's correct that a trait can appear and remain that is neither helpful nor harmful. I left it out of the OP because too much detail would have distracted from the more important points she was asking about, but one additional word (almost everything) would have covered it.

Now, I've seen contradictory definitions of "spandrel." I originally learned it for the reason men have nipples, that it was the remnant of a useful trait in other or earlier situations (the appendix can also be cited as a spandrel by that definition). I'm reading about it and will correct my understanding.

About skin color, melanin is produced in skin because it protects it from excessive ultraviolet light. It's side effects include A) changing, also, the reflection of visible like, so people with more melanin have visibly darker skin, B) reducing the amount of vitamin D produced, causing deficiencies if there's too little sunlight, and C) influencing aesthetics, which can effect mating prospects. We have the wonderful system of tanning that adapts over hours and days, local to the areas of skin that received excess sun, plus a default level of melanin that adapts over generations by mutation and natural selection. Alice Roberts explains this beautifully in her documentary "The Incredible Human Journey" in her episode on why the colonizers of Europe acquired white skin, while almost all of the rest of humanity is tan by default.

Time stamp 47:06

 

[Roboramma]

It's correct that a trait can appear and remain that is neither helpful nor harmful. I left it out of the OP because too much detail would have distracted from the more important points she was asking about, but one additional word (almost everything) would have covered it.

I still disagree regarding the "almost everything".

The issue with spandrels is that any trait that is selected for will come with them. If light weight is selected for in birds, the way it's selected for is perhaps by decreasing bone mass, particularly in the interior of the bone, and that will have other consequences beyond lightness. Any consequences beyond the trait that is selected for can be viewed as spandrels. If you then look at the bone and say "why did weak bones evolve in birds" you'll be asking the wrong question, or at least the answer will include an understanding of not weakness in the bone being selected for (as is obvious by the architecture of the bones which increases their strength in spite of their lighter weight) but lightness of bone. Those are two separate but linked traits and it's the latter that is selected for.

Wallace famously asked how mathematical ability could have been naturally selected in humans, and the answer is that it wasn't, it, too, is a spandrel. It's the consequence of traits that were selected for.

In general its relatively obvious what was and what was not an adaptation, but that's not always true in specific cases, and, anyway, these sorts of traits are far from rare.

It's funny that I'm the one making this argument as I'm usually the adaptationist on this forum. Just try having this discussion with Dinwar.

 

[Mr. Scott]

Wallace famously asked how mathematical ability could have been naturally selected in humans, and the answer is that it wasn't, it, too, is a spandrel. It's the consequence of traits that were selected for.

This is awfully close to a semantic disagreement. The module, neural network, and/or gene complex that resulted in skill with mathematics was an advantage (in some other way or ways) to an ancestor.

Usually I use the word "module" for inherited features generated by genes that endow an advantage, so it won't sound like a feature such as "brittleness" would be confused for an advantage. I wanted to use a less technical word (feature) for a less technical audience. The blind spot is another example of this. It confers a disadvantage and is not a module, but can still be described as a "feature." It's an unfortunate side effect of our retina being built the wrong way, and modules formed that compensated endowed an advantage over how things would have played out in their absence.

An accidental side effect like brittle bones in birds can be reworded as "the form of bones in birds is there because it was, on balance, an advantage to its ancestors, because the side effect of additional brittleness was not severe enough to overcome the advantage of light weight for flight." I don't know why the word "spandrel" is useful in these cases, but since the word was not in the OP, nor was necessary in the OP, it's a bit off-topic.