Catholic vs. Atheist - 2019-05-04 - Lucy part 2

Author Recorded Saturday May 4th, 2019

There are 47 episodes in the Versus:Atheist series.

Recorded February 9th, 2019

Catholic vs. Atheist - 2019-02-09 - Greg

Recorded September 11th, 2016

Catholic vs. Atheist - 2016-09-11 - Renaud

Since her first interview Lucy has been studying evolutionary biology at university. I wanted to ask her about evolution and she was very happy to answer my questions. As always, I really enjoyed talking with her. • Support the CVS Podcast: • Be a guest on a livestream:

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Lucey part two so Lucy you are studying evolutionary biology at University just tell us a little bit about what you've been learning well it's a bit of a mix everything so I've taken this year I had to genetics courses I've had a course on intracellular communication which I really enjoyed I did a research lab microbiology thing and then I continued to volunteer in that lab in the second term I took a comparative anatomy of vertebrates class so that it wasn't quite as technical as I would have liked it to be but yeah like we looked at the ancestral forms and then projected ancestral forms and things like that of different vertebrate lineages and what's the simplest vertebrate the simplest vertebrate is the lamprey it's before a fish so it's kind of like a long tube with a circular face and correctness rasping teeth and what would be the most complex are the biggest vertebrate biggest radio red-eyed blue whale I mean like Megalodon the huge shark was big and there there have been historically tons of very large aquatic animals but today it's over the biggest land dwelling vertebrate today um by mass I think the elephant do all vertebrates today come from one common ancestor yeah I come from that lamprey it wouldn't that lamprey is the basically it's undergone stabilizing selection so basically it is as evolved as your IR it's just the environment that it was in favoured a very specific morphology so it's existed for as long as our lineage has and it's been evolving that entire time but it's been evolving to be more specifically what it is whereas we've been evolving to be different right so it would have evolved and then it's just I mean technically everything is the spectrum so so in evolution we can have one species a and that leads to another species B and both a and B can thrive independently but the stepping stones in between and B don't necessarily thrive is that correct it depends right so it's really easy to kind of fall into this trap of thinking of evolution as having a goal when realistically all evolution is just the process of changes in the wheel frequency which is just versions of genes over time within a population so it's like probability right except that there are factors that favors certain forms so um it's all about surviving to reproduce so they're stabilizing which favors the average there is disruptive which favors the two sides so imagine if you have mice living on a beach and there's white sand and then there is shade so the mice that live on the whites and if they're darker color they're easier to see so those ones will be eaten and they won't survive to reproduce but in the shade the ones that are lighter will be easier to see and they'll be eaten and they won't survive to reproduce so the ones in the mill are okay but not very good at either the white ones are really good for the beach and the black ones are really good for the shade so that would disrupt like if you started with a brown population it would favorite the to kind of extremes and that can lead to speciation then we also have directional selection so that would be like it for example of pepper moths right so during the Industrial Revolution all the trees kind of became covered in smog so the moths that were a darker color were favored and so the entire moth population became darker yeah that's all common sense but how do you get from molecules to man because in Catholic theology and Catholic philosophy there's a principle that you can't give what you don't have so this is called the principle of proportionate causality the cause is always more perfect than the effect in the case of efficient causality so how do you get from molecules to man so it all comes down to mutation so in the genetic code it basically like a new baby will have around 60 new mutations that its parents don't have 60 out of what number we aren't certain because there are pseudogenes of things that look like genes but we don't know what they do and think all funky just give me a ballpark figure a couple million a couple million is it possible to have no mutations if you're really lucky very unlikely it because I mean it can be something as a mutation doesn't necessarily make any difference right a mutation in regions of your DNA that don't code for anything that aren't regulatory so you can have the biggest mutation in the world in there and it won't change anything right is this what they used to call junk DNA yeah and then there's DNA that there even have genes they're called like fossil genes where it used to be useful but we've just turned them off is that something like vestigial genes yeah basically because we don't need them or even like you have genes that are active when you're a baby that aren't active in adulthood so they're kind of five forces that drive evolution and evolution again is just the change in allele frequency was in a population over time so there's natural selection which would be like if you're a mouse and you're white and you live on a black beach then that's not great so you're going to be eaten and you won't have babies then there's sexual selection so that's like when female deer are more likely to mate with male deer who have bigger antlers or something which is really cut that's actually really common in birds of paradise and things like that and you see a huge speciation in clades that have that and there's mutation which is like the source of all differences and then we have gene flow so it's like if you have an island of poppins and all the puffins can interbreed freely but then there's a volcano and you know then there's a huge barrier in between or there's global warming and the middle floods or something like that and the puffins are separated into two groups that can't interbreed across that would be a disruption in gene flow and alleles that are more common in one population won't necessarily be so common in the other and that can change the allele frequencies and then there is genetic drift so that's like if you have a field of flowers and it happens to flood and kill predominantly yellow flowers then there will be fewer yellow flowers in the next generation yeah that's all common sense but how do you get new information into this delicate system by tampering with it randomly with random mutations how are you getting new and useful information into this very very finely tuned and delicate system of information how do you do that so basically it's just a numbers game so occasionally a mutation will cause a small change which will be favorite or else you can have a big change that's suddenly as favorite and bigger differences more change is caused by mutations to a regulatory region or two genes that control other genes so instead of having a small change in the structure of a protein you'll have a small change in how much of that protein is produced which causes a bigger change overall essentially species are just a way of classifying right so and this is actually if you're looking at say human evolution one of the really big debates is at what point are we human right because there's this huge huge line of primates and a primate would include anything from a lemur to a chimpanzee right so new world monkeys old world monkeys all of the great apes lesser apes not everything what's our closest ancestor according to evolution kind of closest behind us is Homo erectus are there any of them walking around today you know no more Homo neanderthalensis is kind of look at cousin of ours and are they walking around today yeah as kind of the evolutionary lineage branches everything is evolving right we still have bacteria today and according to evolution we evolved from bacteria no oh yes so we do have a direct testers that original bacteria that we evolved from is it extinct um we're not certain about what the original on it but yes like it's consider like your grandparents are dead so you don't have direct ancestors but you do have cousins right so with the bacteria we don't have fossils past a certain point genetics we can see common genes between us and bacteria with humans we have fossil evidence we have you know with in some cases we have DNA even from the physical evidence so evolution is making a claim about origins based on patterns that it sees in the fossil record and in DNA right but I think it's fair to say that there might be other explanations and that there could even be better explanations using different ways of interpreting the data no it's not that I believe in evolution it's that looking at all of the evidence it's the only explanation that all of the evidence supports it's coherent it's go ahead yeah it's a coherent story but it's just a story that's my point I think you have to admit there are other ways of looking at the data looking at the facts and there isn't necessarily a causal relationship between the simpler but similar patterns that were lining up in this so-called Tree of Life we've never seen one kind of animal turning into another kind of animal we've never seen that dinosaurs and birds have you seen that do you mean watching with your own eyes because we have examples of that too we've I read about an experiment where they took a unicellular singular celled organism and they grew it in this tank for probably thousands of generations so it was a several-year experiment then they introduced a predator and within a number of generations the single-celled organisms that was the prey had evolved to be 11 cells and was in another few generations it had gone back down to seven or eight because that was more than two I'm not impressed by that if single-cell organisms want to cluster together I don't see that as a change in kind if you want to show me a dog turning into a non dog or a rat turning into a non rat that would be impressive but there are no examples of that so you mentioned three types of selection three types of evolution are they all equally active today yes there would have been disruptive selection to have multiple skin tones and then say in Nordic people it's advantageous to have lighter skin so you could kind of have vitamin D and so there would have been stabilizing selection once there was lighters yet or you can like directional selection to have lighter skin and then stabilizing selection on that skin tone right so that's just a way of talking about what is happening to the individual traits but there are tons and tons of ways to talk about evolution like um another one would be punctuated equilibrium versus gradualism so gradualism would be like over a very very very long time giraffes evolved to have longer necks right each generation having is slightly longer because the ones who had longer necks were more successful at punctuated equilibrium basically means that it's the same for very long time and then suddenly there's a mutation that's very advantageous and so it is selected for so imagining maybe the lampreys if there was a change in their environment where a predator came in and would eat any lampreys that were pink then there would be suddenly a strong selection on any color that could survive right so what we found is that a lot of the intermediate fish tetrapod in between they're kind of we call them fishapods or we call them like it's between efficient and phibian basically so coelacanths are this closest living fish relatives to tetrapods and if you look at their fins as opposed having a very narrow fin that just has the bones and then the skin on them it has a very muscular pen which is you don't another fish so we see that the fins become more muscular and then they're paired and they're able to support the fish and we can actually see lung fish that are able to prop themselves up we see fish that are able to like even walk on land from pond to pond today and then we see that the eyes migrate to the top of the head which means that they were very likely looking at above the water so we see the eyes come to the top of the head they have more limb like fins and then we start to see next so one of these fish was actually born with a neck is that what you're trying to tell me evolution works so so slowly it can work very quickly but on this scale going from fish to amphibians it's not like the the next generation has the next thing right so what you're saying is the advantage you have over your parents is a negligible advantage is that what you're saying not necessarily you basically your parents are more fit than their peers okay piers so what you're saying is that those that survive are negligibly more fit than their peers and that's why they're survived because they're negligibly more fit and there's absolutely they're random events as well like if you talk about the bridges shell but it's descent with modification so they're tiny changes there are tiny changes in fitness and those affects who survives but it happens on such a large scale it happens over such a long time period that negligible changes do matter but negligible improvements are negligible right that means we can neglect them they're insignificant anything okay but it's the thing is it has to be big enough to make that difference right if you're conserving energy if you have better access to food if you have better access to mates you can't neglect it it's small considering but it takes millions of years for these negligible improvements to accumulate right and to become significant or maybe it's not a slow change maybe one of the babies is born with a slightly flexible neck is that what you're saying if there's a change in a regulatory sequence you could end up with an extra neck bone right so that that's quite a big difference right or there are metabolic differences as well you can look at any factor of an animal's niche is a factor in its fitness right so even if it's better at finding places to hide that could be selected for him so allegedly non-flying creatures evolved into flying creatures with feathers and wings all right dinosaurs we think that feathers evolved as like part of a thermoregulation system and it could be peta morphism we're like hatchlings would have feathers to keep them warm while they have a small body size and then they will be lost later and then eventually it became advantageous for that it's a change in life history so the feathers would not be lost they keep that juvenile state so the feathers were there to begin with so this is not very impressive we already have the feathers so let's talk about that transition from non feathers to feathers let's talk about that I know I won't pretend to understand how exactly feathers arose but so it could have been some kind of integumentary so it could have been a specialized scale or something like that but there's a mutation that allows let's say a scale to specialize into being elongated this might provide more warmth because it protects the skin and for an animal that can't it's an ectotherm right it relies on it's an external environment to maintain its body heat that allows that to have a little bit more control so then it I doesn't freeze to death or it could be something as random is like it has no effect and so that one made sweat and like equally with other ones they have the same random annotation not even like it could be you have brown eyes that has no effect on your fitness let's say that means that you have kids equally as someone with green eyes or blue eyes it has no effect so it doesn't matter then you're passing on your genes even though there's no effect they're not advantageous they're not being selected or they're just not being selected against so it spread in the population because it had no negative effect and it had no positive effect and eventually people have it right it's kind of immaterial so this could happen the mutation could spread and then another mutation arises that allows these elongated scales to have barbs on them and let's say that that one is selected for because it can help to regulate body temperature that one like we'll call them reptiles because that's probably what they were that reptile can't be a little bit more successful because maybe it's a cold winter and it can resist that right eventually that spreads and more of the population has it and then me a mutation arises that the feathers are flashy er and that's sexually selected for and so it becomes like and then it can species and things like that so if you argue that the potential for something is there it goes back so far right because if a feather evolved from a scale any kind of integument has the potential to be a scale or and then it goes back to what like the plasma membrane but I would see that as an argument for evolution because it's just a small mutation in existing DNA right then we can definitely see it change from something more like a filament it almost analogous to fur just as a kind of warm layer when you see a change from that to the bladed feathers that we see on birds right that could be good for flight and actually we even have a name for genes that are duplicated and can then you repurposed paralog is genes is when you get an extra copy of the gene and then the first gene copy can control the original function and the second gene copy is free to to explore exactly yeah as mutations arise it is not necessarily selective yes because it's not impeding that original function and so mutations can kind of add up and the function can change so we've looked at the past through the lens of evolution now let's turn and look toward the future because we are far more evolved than a fish for example and we cultivate fish as pets as food and it's possible that there's a race of beings that are evolved far beyond us and maybe they live out in outer space and if they come back and they want to cultivate us as pets and use our flesh as food so what would you say to this super evolved creature that came back and wanted to take you as a pet or to eat us food what would you say to them I mean personally I may not enjoy being a pet but I think that I think absolutely evolution is still happening absolutely there's a like there is a future of life we think that our solar system is only about halfway through its lifespan so and everything that's happening there's no way that we're finished right um the thing about evolution and the thing about science like this is that it there is no good or bad it just it's random right it just but you don't you see that it's absolutely wrong for humans to be taken as pets or to be used for food I don't think that we are somehow the chosen ones viruses viruses kill people bacteria kill people like does that mean the bacteria are king of us it's not evil when they do because they don't have free will and a reason but we do that's why this is the whole essence of what it is to be human is to have free will and reason I don't believe that it would be wrong for them to come and eat us like I I wouldn't personally like it but I mean the Gazelle doesn't like to be eaten by the lion right even if there are a million times more advanced than we are it's categorically wrong for them to enslave us to take those pets or to use us as food don't you see that the thing about evolution that we have to remember is that anything that survives tons of things don't we've had so many mass extinctions right so death is our friend and evolution yeah so just to end the interview perhaps you could tell us a little bit about what you're excited about moving forward with your career in biology well I'm really excited about learning about the human microbiome because our bodies cannot digest a lot of the foods that we eat and we rely on the bacteria that live in US and on us to protect us from infection and then to help us digest our food they train our immune system they help with angiogenesis the production of red blood cells we have huge it's called dysbiosis if you say take antibiotics and it kills the bacteria in your stomach or in your large intestine technically it can have huge effects on your health right and that's really really strong coevolution because we a lot of the foods that we make use of we wouldn't be able to eat if it weren't for those bacteria right it's the same thing as if you think of cows they would not be able to eat grass and digestive and get the nutrients that they need from it if they weren't ruminants if they didn't have those four stomachs and the bacteria associated with them so as we research that and as we learn more about that we are understanding the link between the human microbiome and all sorts of diseases especially modern things like allergies even depression and anxiety autism and then obvious ones leaky gut syndrome all sorts of off like autoimmune diseases lupus multiple sclerosis tons and tons of different disorders so I'm really excited to learn about how we can how an understanding of that gut microbiome and the makeup of the human microbiome can help us to come up with really tailored practices treatments and then antibiotic resistance is a huge problem and it's only going to get worse so coming up with a solution another way of killing bacteria so that we don't get infections hopefully that they can't resist actually one of the ones that are excited about is page therapy so that refers to bacterial pages or viruses that attack bacteria and one of the advantages is that it's these bacteria these viruses are highly specific so they would kill the exact strain of bacteria that they were specialized to so if you had an infection they could kill only those bacteria and your natural microbiome wouldn't be killed as it would be with antibiotics problems with this one of the kind of the most serious problem ignoring the difficulties that we have in actually making it happen is that they can pick up these that these viruses can pick up pathogenicity islands so DNA like factors that allow bacteria to be virulent and they can transfer them to nonviolent bacteria and make them dangerous it would be really exciting if I could be involved in that process and if not it'll be exciting to just hear about what's going on with that all you got to do is all you got to do do