evolution & Taxonomy
What is Evolution?
Evolution is, quite simply, change over time. As we well know, all things change over time. The Earth changes, we change, the environment changes, animals change, etc. One can call the change of technology an evolution of technology. In the same way, the change of a species or an organism can be called evolution. As this is biology, we'll be discussing living things only. To understand how change happens in organisms, let's go back to the basics: DNA.
We know that DNA is a sequence of nitrogenous bases (A, T, C, and G) that are paired with each other (A with T and C with G) and held together by a sugar phosphate backbone. The whole thing is twisted into a double helix structure. The sequence of these base pairs can have many different variations. DNA is unique to each organism and it is also the genetic blueprint that makes an organism the way it is. The DNA determines how an organism is built and how it functions. If the DNA of an organism changes, the organism itself changes. Within the DNA are genes. Genes are segments of DNA that can perform specific functions. All of the variations of different genes that are available to the next generation are called the gene pool. If new genes are introduced into a gene pool, then new traits can appear that may make an organism more or less fit for its environment. The introduction of new genes means that the DNA now has new information and is therefore changed. Remember how I said that if the DNA changes, so does the organism? So the evolution of living things isn't just change over time, it's also the change of DNA over time.
So, all the variations of different genes that are available to the next generation are called the gene pool. What does this mean? Well, genes, like I said above, can perform specific functions. The variations of a gene all do the same thing (eg. determine hair colour) but they just do it differently. These variant genes are called alleles. There are five different ways that a gene pool can change: natural selection, mutations, genetic drift, gene flow and non-random mating. Natural selection is the 'survival of the fittest' concept that Darwin came up with. Basically, the organism most suited for survival in its environment is more likely to survive and therefore more likely to pass on its genes. This means that the genes best adapted to help an organism survive are the genes that are more likely to be passed on to the offspring. Mutations are a change in the DNA. More often than not, they are harmful or neutral but sometimes, they can be helpful. Genetic drift is when certain genes are reduced in frequency or wiped out of the gene pool due to a random event (such as if a natural disaster killed a bunch of people. They wouldn't be able to produce more offspring and pass on their genes if they're dead). Gene flow is the sharing of genes from one population to another. If gene flow stops, the populations can have their own random mutations that don't get shared with the other population and therefore develop differently. Non-random mating is the process of an organism choosing its mate (which, in animals, is incredibly rare). Three types of non-random mating are harems (one male to a lot of females), assortative mating (choosing those similar to you), and sexual selection (choosing a mate based on criteria like size, territory, song, colour, etc.). All these things affect the way a population evolves because they all affect which genes are passed on to the next generation.
It is important to note that when evolutionary pressure (like a change in environment) is present, most life is not suited for surviving it. In fact, most life will die and only those few that are able to adapt or already posses a trait that will help them survive will live and reproduce. Micro-evolution is all about a population generally shifting towards a new or different trait. There are three main ways a population can change: stabilizing selection, directional selection, and disruptive selection. Stabilized selection is when evolutionary pressure is put on the two extremes of a certain trait and favours the intermediate. Let's use the colour of organisms in a population as an example. Evolutionary pressure may be placed on the white and black individuals and so the grey ones are favoured. Grey is already the most common, but it becomes even more common. Stabilizing selection makes the most common even more common. Directional selection is when the population shifts towards one extreme because it is favoured. So if the environment suddenly changes colour and it becomes easier for the black individuals to hide from predators, evolutionary pressure is placed on the white and grey individuals. The black ones will survive while the white ones become easier targets for predators and therefore become less common (survival of the fittest!). Disruptive selection is when both extremes are favoured and the intermediate traits receive the evolutionary pressure. This would mean that the black and white individuals live while the grey ones die out. The change in the most common colours of organisms in the population shows that evolution is happening. The population is changing.
Macro-evolution, also called speciation, is the making of a new species. This can happen through divergent evolution and convergent evolution. Divergent evolution is when a small group splits off from the rest of the population and inhabits a new area. For the group to evolve into a new species, it has to be isolated from the larger population (no gene flow!), it has to have completely different environmental pressures, and it has to develop its own mutations. The two species will share a common ancestor and will therefore have similar DNA. Convergent evolution is when two different species inhabit the same area and develop similar characteristics. This happens because they have the same environmental pressures. They do not have a common ancestor so they do not have similar DNA.
Evolution of organisms is the change in DNA over time. Micro-evolution is the change of organisms within a species and macro-evolution is the making of a new species. Micro-evolution happens when the gene pool changes and when the population changes (which results in altered allele frequencies). Macro-evolution happens when an isolated population evolves differently than their kin and when two species develop similarly to create new species.
We know that DNA is a sequence of nitrogenous bases (A, T, C, and G) that are paired with each other (A with T and C with G) and held together by a sugar phosphate backbone. The whole thing is twisted into a double helix structure. The sequence of these base pairs can have many different variations. DNA is unique to each organism and it is also the genetic blueprint that makes an organism the way it is. The DNA determines how an organism is built and how it functions. If the DNA of an organism changes, the organism itself changes. Within the DNA are genes. Genes are segments of DNA that can perform specific functions. All of the variations of different genes that are available to the next generation are called the gene pool. If new genes are introduced into a gene pool, then new traits can appear that may make an organism more or less fit for its environment. The introduction of new genes means that the DNA now has new information and is therefore changed. Remember how I said that if the DNA changes, so does the organism? So the evolution of living things isn't just change over time, it's also the change of DNA over time.
So, all the variations of different genes that are available to the next generation are called the gene pool. What does this mean? Well, genes, like I said above, can perform specific functions. The variations of a gene all do the same thing (eg. determine hair colour) but they just do it differently. These variant genes are called alleles. There are five different ways that a gene pool can change: natural selection, mutations, genetic drift, gene flow and non-random mating. Natural selection is the 'survival of the fittest' concept that Darwin came up with. Basically, the organism most suited for survival in its environment is more likely to survive and therefore more likely to pass on its genes. This means that the genes best adapted to help an organism survive are the genes that are more likely to be passed on to the offspring. Mutations are a change in the DNA. More often than not, they are harmful or neutral but sometimes, they can be helpful. Genetic drift is when certain genes are reduced in frequency or wiped out of the gene pool due to a random event (such as if a natural disaster killed a bunch of people. They wouldn't be able to produce more offspring and pass on their genes if they're dead). Gene flow is the sharing of genes from one population to another. If gene flow stops, the populations can have their own random mutations that don't get shared with the other population and therefore develop differently. Non-random mating is the process of an organism choosing its mate (which, in animals, is incredibly rare). Three types of non-random mating are harems (one male to a lot of females), assortative mating (choosing those similar to you), and sexual selection (choosing a mate based on criteria like size, territory, song, colour, etc.). All these things affect the way a population evolves because they all affect which genes are passed on to the next generation.
It is important to note that when evolutionary pressure (like a change in environment) is present, most life is not suited for surviving it. In fact, most life will die and only those few that are able to adapt or already posses a trait that will help them survive will live and reproduce. Micro-evolution is all about a population generally shifting towards a new or different trait. There are three main ways a population can change: stabilizing selection, directional selection, and disruptive selection. Stabilized selection is when evolutionary pressure is put on the two extremes of a certain trait and favours the intermediate. Let's use the colour of organisms in a population as an example. Evolutionary pressure may be placed on the white and black individuals and so the grey ones are favoured. Grey is already the most common, but it becomes even more common. Stabilizing selection makes the most common even more common. Directional selection is when the population shifts towards one extreme because it is favoured. So if the environment suddenly changes colour and it becomes easier for the black individuals to hide from predators, evolutionary pressure is placed on the white and grey individuals. The black ones will survive while the white ones become easier targets for predators and therefore become less common (survival of the fittest!). Disruptive selection is when both extremes are favoured and the intermediate traits receive the evolutionary pressure. This would mean that the black and white individuals live while the grey ones die out. The change in the most common colours of organisms in the population shows that evolution is happening. The population is changing.
Macro-evolution, also called speciation, is the making of a new species. This can happen through divergent evolution and convergent evolution. Divergent evolution is when a small group splits off from the rest of the population and inhabits a new area. For the group to evolve into a new species, it has to be isolated from the larger population (no gene flow!), it has to have completely different environmental pressures, and it has to develop its own mutations. The two species will share a common ancestor and will therefore have similar DNA. Convergent evolution is when two different species inhabit the same area and develop similar characteristics. This happens because they have the same environmental pressures. They do not have a common ancestor so they do not have similar DNA.
Evolution of organisms is the change in DNA over time. Micro-evolution is the change of organisms within a species and macro-evolution is the making of a new species. Micro-evolution happens when the gene pool changes and when the population changes (which results in altered allele frequencies). Macro-evolution happens when an isolated population evolves differently than their kin and when two species develop similarly to create new species.
Evolution: Fact or Fiction?
Does evolution actually happen? Is it real? The theory of evolution is a theory that is widely accepted as a way to explain the varieties of life on Earth. In fact, there is a lot of evidence to suggest that evolution has happened in the past and happens now. But what do I believe? Well, it's complicated, so let's take it piece by piece. I certainly think that micro-evolution happens. I find it perfectly realistic that a species changes within that species. But what about macro-evolution, you say? Not so much. So let's take a look at evolution and why I do or do not find it believable starting with micro-evolution.
As I have said in the above paragraph and also in the above question, micro-evolution is the change of organisms within a species. This isn't the idea that humans came from apes, this is just the idea that a population of organisms will develop and display different traits if it will help them to survive. An example of this in the past is the Peppered Moth example. Before the Industrial Revolution, the peppered moths were living quite peacefully in the Manchester Forest in England, not suspecting anything big would happen soon. The white moths blended in quite nicely with the white trees in the forest and were harder for predators to see. The black variety stood out magnificently against the white trees and were easier for predators to see and therefore eat. So the white ones were the fittest and therefore the most common. Until the Industrial Revolution happened and released a bunch of pollution into the air. The white trees became black with soot. Now the white moths stood out and the black ones blended in to their environment. The population shifted towards the gene that made a moth black instead of white. That, my friends, is micro-evolution at work. In fact, it's a lovely example of natural selection. Natural selection, as we know, is one of the five ways a gene pool can change, along with mutations, genetic drift, gene flow, and non-random mating. All of these make sense when thought through logically. Each of these methods affect which genes are passed on to the offspring and the frequency of the alleles. Natural selection states that the fittest organism will survive to mate with other fit organisms and pass on the genes that made it fit. Of course. Those that carry genes that make them susceptible to the dangers of their environment will likely die and if they are more likely to die, they are less likely to live to mate and pass on their genes. Obviously. So the fit genes are more present because those who carried them survived because of them. If mutations make an organism weak, it dies and can't pass on the harmful mutation. If the mutation makes it strong, it lives and can pass on the helpful mutation. Genetic drift wipes out genes, thus changing allele frequencies. Gene flow ensures that mutations and fit genes are passed around through the next generation. Non-random mating means that certain individuals carrying certain genotypes that give them the desired phenotypes will be more likely to find a mate and pass on the genes that allowed them to mate to their offspring who will then be more likely to find a mate themselves. These are all logical. Obviously, organisms change as time goes on. Look at the Earth. It hasn't stayed the same, in fact, it's changed drastically over the course of its existence. Life had to either adapt or die when these changes happened. Considering that there's still life, it probably adapted. So yes, I believe in micro-evolution.
Let's tackle the tricky beast: macro-evolution. Macro-evolution (or speciation) is the making of a species. So we know about divergent and convergent evolution, but how does it really happen? Darwin's theory is called gradualism. Gradualism is basically a species gradually, over a long time, changing into a new species. But that takes a while and there is a lack of intermediate fossils to show the process. Considering that fossilization is a difficult process, you might say that it's not a problem. But gradualism is very slow. There's all the time in the world to make fossils. So intermediate fossils shouldn't be rare at all. Eldridge and Gould proposed their solution of Punctuated Equilibrium. Punctuated equilibrium is when the "less fit but still survivable" members of a population exist at the periphery of that population. They are pushed to inhabit the less desirable extremes of the habitat and create their own little population, isolated from the fitter group. Because their environment is harsh, they need to adapt or die. If they manage to adapt, they do so quickly in order to survive. During this, the fitter population and the less fit population cannot share genes at all. They need to be either physically separated (allopatric speciation) or isolated in a reproductive sense (sympatric speciation). So they evolve differently and produce different mutations and favour different genes until they are no longer the same species as the others in a short amount of time. That's where this stops being about science and becomes more of a leap of faith for me. How can an organism lose or gain or change enough of its DNA so quickly? Ultimately, what's causing the organism to change is its DNA. The organism has new DNA that it never had before. Maybe some of its existing information changed. Maybe it gained DNA from a retrovirus or something. The point is, the organism's DNA has changed therefore the organism has changed. But so quickly? It happens so rapidly during the lifespan of only a few organisms of a population that there is a slim-to-none chance that a fossil will be made of it. Which explains the lack of intermediate fossils but creates another problem. Logically, I can't connect these dots. How can an organism have so much of its DNA changed so that it can no longer reproduce with the other population of organisms? How much and what DNA needs to change for that to happen?
I am aware that there is some pretty great evidence for macro-evolution. There are four types: fossil evidence, comparative anatomy, comparative embryology, and molecular evidence. Fossil evidence is basically intermediate fossils. It shows a clear picture of evolution in progress. But how do we know that it actually is an in-between phase? Are we just seeing what we want to see or are we looking with open minds, ready to explore as deeply as we can without letting our personal bias get in the way? Scientists are humans too. They have a bias and a hypothesis or a theory they want to prove. It's incredibly hard to be completely impartial. Even when you try, it can be a subconscious thing or a habit to reject what you don't believe and accept what you do. That's why changing beliefs are hard. It's a habit. The second, comparative anatomy, is pretty cool. It explores the relationships between homologous structures and analogous structures. If organisms have a similar structure (for example, an arm) that is built similarly (with the same bones in the same places), we can infer that they have similar DNA that coded to build those bones and those muscles and those cells that make up that structure. If they have similar DNA, they must be related, right? Maybe. Maybe not. Who's to say that they did come from the same ancestor? Maybe they were just made that way from the beginning. Comparing analogous structures isn't actually good evidence at all. It's when we compare structures on two organisms used for the same thing (let's say a bird's wing vs. a butterfly's wing) that are not built the same and therefore the organisms do not have similar DNA and do not have a common ancestor. Then there's comparative embryology. The embryo only displays the most basic or primitive genes because it's still forming. If the embryos of different organisms look the same, they must have the same genes. Again, I'm not quite convinced that looking the same or having similar genes makes two organisms related. Maybe the gene an organism has codes for a protein that is necessary for their survival and that protein just so happens to be necessary for another organism's survival as well. Coincidence? I think maybe. Besides, we've already figured out that about 8% of the human genome is made up of retroviruses and related elements (according to Survival of the Sickest by Sharon Moalem). Is it entirely impossible that the same or a similar retrovirus that migrated into the human genome migrated into another organism's genome? Certainly not (but I guess it depends on just how much DNA is similar. If it's more than 8%, then my argument seems to fall apart, but maybe some organisms just had similar environmental pressures that caused them to evolve similarly. Just because a duck-billed platypus has a duck bill doesn't mean it's related to a duck. Or maybe I just have more questions than I have answers). And last, but not least, is molecular evidence, where we zoom in to look directly at the DNA. What do genes do? They make proteins! What are proteins made of? Amino acids! If two organisms share similar amino acid sequences, then we can infer that they have similar genes that coded for those sequences. Furthermore, we can use this evidence to show how long two populations have been separated. The more changes in the sequence, the longer they've been apart. Also, if we look directly at the DNA, it can show us exactly which parts of the DNA in one species are similar to the DNA in another species. This looks an awful lot like DNA is the answer to all of our problems. Maybe we're just putting too much importance on DNA. DNA shows us how things are built but just because I have an arm and a monkey has an arm doesn't mean that we're related.
To hopefully clear things up, I'm Christian. I don't believe the Earth came into being the same way most people who believe in evolution believe the Earth came into being. The Big Bang Theory is not my theory. I don't believe it, but if I did, my beliefs surrounding evolution might be different. If I believed that a whole bunch of molecules suddenly came together and created something out of nothing, I would most certainly believe that the Earth started with the most basic life. It makes sense. But look at all the complex life around you! There must have been a whole lot of changes going on with the simple organisms to make them so complex. So my answer would be evolution. But since I don't believe in the Big Bang Theory, I find it easier to reject macro-evolution. For those who do believe the Earth was a random creation, they might find it harder to reject and seriously question macro-evolution because it's the only explanation for the reality of complex life forms. Why would anyone question their most fundamental beliefs? It's scary. If I find that the questions I've asked regarding evolution and the Big Bang Theory have led me to not believe in them, I would find that I have lost my beliefs on a subject that I find important. I need to find something I do believe. It's not easy. So that is why some people believe in evolution, and also why I don't. I'm not saying that everyone who believes in evolution is stupid or uninformed or didn't ask enough questions. I'm also not saying that macro-evolution is a bad answer or not realistic at all or that the reasons I've stated are the only ways someone could possibly believe in evolution. In fact, I'm not entirely convinced myself that it didn't happen. I'm simply exploring why some people believe what I don't believe because it helps me to understand and explain why I don't believe it. I believe in micro-evolution but not macro-evolution. I understand that this is mostly based on personal opinion, but considering this question asked for that, I hope it's valid to say that I reject macro-evolution on faith-based grounds.
As I have said in the above paragraph and also in the above question, micro-evolution is the change of organisms within a species. This isn't the idea that humans came from apes, this is just the idea that a population of organisms will develop and display different traits if it will help them to survive. An example of this in the past is the Peppered Moth example. Before the Industrial Revolution, the peppered moths were living quite peacefully in the Manchester Forest in England, not suspecting anything big would happen soon. The white moths blended in quite nicely with the white trees in the forest and were harder for predators to see. The black variety stood out magnificently against the white trees and were easier for predators to see and therefore eat. So the white ones were the fittest and therefore the most common. Until the Industrial Revolution happened and released a bunch of pollution into the air. The white trees became black with soot. Now the white moths stood out and the black ones blended in to their environment. The population shifted towards the gene that made a moth black instead of white. That, my friends, is micro-evolution at work. In fact, it's a lovely example of natural selection. Natural selection, as we know, is one of the five ways a gene pool can change, along with mutations, genetic drift, gene flow, and non-random mating. All of these make sense when thought through logically. Each of these methods affect which genes are passed on to the offspring and the frequency of the alleles. Natural selection states that the fittest organism will survive to mate with other fit organisms and pass on the genes that made it fit. Of course. Those that carry genes that make them susceptible to the dangers of their environment will likely die and if they are more likely to die, they are less likely to live to mate and pass on their genes. Obviously. So the fit genes are more present because those who carried them survived because of them. If mutations make an organism weak, it dies and can't pass on the harmful mutation. If the mutation makes it strong, it lives and can pass on the helpful mutation. Genetic drift wipes out genes, thus changing allele frequencies. Gene flow ensures that mutations and fit genes are passed around through the next generation. Non-random mating means that certain individuals carrying certain genotypes that give them the desired phenotypes will be more likely to find a mate and pass on the genes that allowed them to mate to their offspring who will then be more likely to find a mate themselves. These are all logical. Obviously, organisms change as time goes on. Look at the Earth. It hasn't stayed the same, in fact, it's changed drastically over the course of its existence. Life had to either adapt or die when these changes happened. Considering that there's still life, it probably adapted. So yes, I believe in micro-evolution.
Let's tackle the tricky beast: macro-evolution. Macro-evolution (or speciation) is the making of a species. So we know about divergent and convergent evolution, but how does it really happen? Darwin's theory is called gradualism. Gradualism is basically a species gradually, over a long time, changing into a new species. But that takes a while and there is a lack of intermediate fossils to show the process. Considering that fossilization is a difficult process, you might say that it's not a problem. But gradualism is very slow. There's all the time in the world to make fossils. So intermediate fossils shouldn't be rare at all. Eldridge and Gould proposed their solution of Punctuated Equilibrium. Punctuated equilibrium is when the "less fit but still survivable" members of a population exist at the periphery of that population. They are pushed to inhabit the less desirable extremes of the habitat and create their own little population, isolated from the fitter group. Because their environment is harsh, they need to adapt or die. If they manage to adapt, they do so quickly in order to survive. During this, the fitter population and the less fit population cannot share genes at all. They need to be either physically separated (allopatric speciation) or isolated in a reproductive sense (sympatric speciation). So they evolve differently and produce different mutations and favour different genes until they are no longer the same species as the others in a short amount of time. That's where this stops being about science and becomes more of a leap of faith for me. How can an organism lose or gain or change enough of its DNA so quickly? Ultimately, what's causing the organism to change is its DNA. The organism has new DNA that it never had before. Maybe some of its existing information changed. Maybe it gained DNA from a retrovirus or something. The point is, the organism's DNA has changed therefore the organism has changed. But so quickly? It happens so rapidly during the lifespan of only a few organisms of a population that there is a slim-to-none chance that a fossil will be made of it. Which explains the lack of intermediate fossils but creates another problem. Logically, I can't connect these dots. How can an organism have so much of its DNA changed so that it can no longer reproduce with the other population of organisms? How much and what DNA needs to change for that to happen?
I am aware that there is some pretty great evidence for macro-evolution. There are four types: fossil evidence, comparative anatomy, comparative embryology, and molecular evidence. Fossil evidence is basically intermediate fossils. It shows a clear picture of evolution in progress. But how do we know that it actually is an in-between phase? Are we just seeing what we want to see or are we looking with open minds, ready to explore as deeply as we can without letting our personal bias get in the way? Scientists are humans too. They have a bias and a hypothesis or a theory they want to prove. It's incredibly hard to be completely impartial. Even when you try, it can be a subconscious thing or a habit to reject what you don't believe and accept what you do. That's why changing beliefs are hard. It's a habit. The second, comparative anatomy, is pretty cool. It explores the relationships between homologous structures and analogous structures. If organisms have a similar structure (for example, an arm) that is built similarly (with the same bones in the same places), we can infer that they have similar DNA that coded to build those bones and those muscles and those cells that make up that structure. If they have similar DNA, they must be related, right? Maybe. Maybe not. Who's to say that they did come from the same ancestor? Maybe they were just made that way from the beginning. Comparing analogous structures isn't actually good evidence at all. It's when we compare structures on two organisms used for the same thing (let's say a bird's wing vs. a butterfly's wing) that are not built the same and therefore the organisms do not have similar DNA and do not have a common ancestor. Then there's comparative embryology. The embryo only displays the most basic or primitive genes because it's still forming. If the embryos of different organisms look the same, they must have the same genes. Again, I'm not quite convinced that looking the same or having similar genes makes two organisms related. Maybe the gene an organism has codes for a protein that is necessary for their survival and that protein just so happens to be necessary for another organism's survival as well. Coincidence? I think maybe. Besides, we've already figured out that about 8% of the human genome is made up of retroviruses and related elements (according to Survival of the Sickest by Sharon Moalem). Is it entirely impossible that the same or a similar retrovirus that migrated into the human genome migrated into another organism's genome? Certainly not (but I guess it depends on just how much DNA is similar. If it's more than 8%, then my argument seems to fall apart, but maybe some organisms just had similar environmental pressures that caused them to evolve similarly. Just because a duck-billed platypus has a duck bill doesn't mean it's related to a duck. Or maybe I just have more questions than I have answers). And last, but not least, is molecular evidence, where we zoom in to look directly at the DNA. What do genes do? They make proteins! What are proteins made of? Amino acids! If two organisms share similar amino acid sequences, then we can infer that they have similar genes that coded for those sequences. Furthermore, we can use this evidence to show how long two populations have been separated. The more changes in the sequence, the longer they've been apart. Also, if we look directly at the DNA, it can show us exactly which parts of the DNA in one species are similar to the DNA in another species. This looks an awful lot like DNA is the answer to all of our problems. Maybe we're just putting too much importance on DNA. DNA shows us how things are built but just because I have an arm and a monkey has an arm doesn't mean that we're related.
To hopefully clear things up, I'm Christian. I don't believe the Earth came into being the same way most people who believe in evolution believe the Earth came into being. The Big Bang Theory is not my theory. I don't believe it, but if I did, my beliefs surrounding evolution might be different. If I believed that a whole bunch of molecules suddenly came together and created something out of nothing, I would most certainly believe that the Earth started with the most basic life. It makes sense. But look at all the complex life around you! There must have been a whole lot of changes going on with the simple organisms to make them so complex. So my answer would be evolution. But since I don't believe in the Big Bang Theory, I find it easier to reject macro-evolution. For those who do believe the Earth was a random creation, they might find it harder to reject and seriously question macro-evolution because it's the only explanation for the reality of complex life forms. Why would anyone question their most fundamental beliefs? It's scary. If I find that the questions I've asked regarding evolution and the Big Bang Theory have led me to not believe in them, I would find that I have lost my beliefs on a subject that I find important. I need to find something I do believe. It's not easy. So that is why some people believe in evolution, and also why I don't. I'm not saying that everyone who believes in evolution is stupid or uninformed or didn't ask enough questions. I'm also not saying that macro-evolution is a bad answer or not realistic at all or that the reasons I've stated are the only ways someone could possibly believe in evolution. In fact, I'm not entirely convinced myself that it didn't happen. I'm simply exploring why some people believe what I don't believe because it helps me to understand and explain why I don't believe it. I believe in micro-evolution but not macro-evolution. I understand that this is mostly based on personal opinion, but considering this question asked for that, I hope it's valid to say that I reject macro-evolution on faith-based grounds.
Survival of the sickest
Chapter 6: Jump Into The Gene Pool
(Click on the above link to get the powerpoint. The notes in the powerpoint are important.)
(Click on the above link to get the powerpoint. The notes in the powerpoint are important.)
Dichotomous key
1b Coloured............2
1a Not Coloured............3
2b Not One Colour............Sir Arthur Conan Doyle
2a One Colour............4
3b Not Staedtler............5
3a Staedtler............6
4b Not Bright............7
4a Bright............8
5b Has a 'B'............9
5a Has no 'B'............Jules Verne
6b Has a 'B'............10
6a Has no 'B'............Ernest Hemingway
7b Green............J.R.R. Tolkien
7a Not Green............11
8b Not Rainbow Colours............Jane Austen
8a Rainbow Colours............12
9b Not 2B............Mary Shelley
9a 2B............13
10b 6B............George Orwell
10a Not 6B............Fyodor Dostoevsky
11b Purple............Joseph Conrad
11a Not Purple............Wilfred Owen
12b Warm Colours............14
12a Not Warm Colours............Arthur Miller
13b Shorter Than 10cm............William Shakespeare
13a Not Shorter Than 10cm............James Herriot
14b Red............Edgar Allan Poe
14a Not Red............Charles Dickens
In this dichotomous key, I classified fifteen different pencils of mine, both coloured and not. I used characteristics of the pencils like colours and the softness (B) or hardness (H) of the graphite. They are named after authors and poets. Dichotomous keys are used to classify organisms and this is useful because it helps us to see the relationships between organisms. From that, we can hopefully draw conclusions as to evolutionary relationships as well (it makes it easier to see if organism 1 evolved from organism 2). The problem is that everyone has a bias. The people who create the classification system consider certain characteristics to be more important than others and that is based entirely on what they think is important. Others might find different characteristics to be important when trying to figure out evolutionary relationships, or they might think that an organism is classified incorrectly. For example, I used the classification 'bright' and 'not bright' when classifying the coloured pencils and I used that to separate J.R.R. Tolkien (the darker green), Wilfred Owen (the brown-red one), and Joseph Conrad (the purple one that looks blue in the photo) from the others. Others might wonder why I put some of those in the 'not bright' category instead of the 'bright' because to them, those colours are bright. To me, they aren't, but that's based entirely on my own preconceptions around those colours. Or people might wonder why I separated the Staedtler brand pencils from the not Staedtler brand pencils because that is entirely arbitrary. I just like Staedtler brand the best.
1a Not Coloured............3
2b Not One Colour............Sir Arthur Conan Doyle
2a One Colour............4
3b Not Staedtler............5
3a Staedtler............6
4b Not Bright............7
4a Bright............8
5b Has a 'B'............9
5a Has no 'B'............Jules Verne
6b Has a 'B'............10
6a Has no 'B'............Ernest Hemingway
7b Green............J.R.R. Tolkien
7a Not Green............11
8b Not Rainbow Colours............Jane Austen
8a Rainbow Colours............12
9b Not 2B............Mary Shelley
9a 2B............13
10b 6B............George Orwell
10a Not 6B............Fyodor Dostoevsky
11b Purple............Joseph Conrad
11a Not Purple............Wilfred Owen
12b Warm Colours............14
12a Not Warm Colours............Arthur Miller
13b Shorter Than 10cm............William Shakespeare
13a Not Shorter Than 10cm............James Herriot
14b Red............Edgar Allan Poe
14a Not Red............Charles Dickens
In this dichotomous key, I classified fifteen different pencils of mine, both coloured and not. I used characteristics of the pencils like colours and the softness (B) or hardness (H) of the graphite. They are named after authors and poets. Dichotomous keys are used to classify organisms and this is useful because it helps us to see the relationships between organisms. From that, we can hopefully draw conclusions as to evolutionary relationships as well (it makes it easier to see if organism 1 evolved from organism 2). The problem is that everyone has a bias. The people who create the classification system consider certain characteristics to be more important than others and that is based entirely on what they think is important. Others might find different characteristics to be important when trying to figure out evolutionary relationships, or they might think that an organism is classified incorrectly. For example, I used the classification 'bright' and 'not bright' when classifying the coloured pencils and I used that to separate J.R.R. Tolkien (the darker green), Wilfred Owen (the brown-red one), and Joseph Conrad (the purple one that looks blue in the photo) from the others. Others might wonder why I put some of those in the 'not bright' category instead of the 'bright' because to them, those colours are bright. To me, they aren't, but that's based entirely on my own preconceptions around those colours. Or people might wonder why I separated the Staedtler brand pencils from the not Staedtler brand pencils because that is entirely arbitrary. I just like Staedtler brand the best.