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Stellalarella

the unscientific american watches a mammal walk into the water and grow fins.

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OK, so here I am--average mom, homeschooling the people, learning latin, and mainly doing experiments on whether or not I can buy healthy food for my 8 and stay under budget.

 

In my spare time, though, I burn the midnight oil reading books like, "North and South Pole," "The Disappearing Spoon," and last but not least "The Faith of Scientists." (The last book is a collection of scientists' own writing on their faith or non-faith.)

 

I really enjoy reading about how the earth's spreading seafloor records earth's changing magnetism over billions of years. It's explained in detail and I get it. It makes sense to me. I can read a huge volume explaining scientists' thoughts on faith and religion and I can get it--both of them, the faithful and those who are secure in the belief that the earth was not created. I can read a book about chemistry and understand how we know how elements form, break down, spread throughout the universe--it makes sense to me and I get it.

 

But when I put a video on for my kids and a picture of a mammal pops up and the slow drone of the announcer tells us all (while the pictures show it) how this mammal lost its legs, grew fins, etc, etc, etc, and turned into a dolphin, I JUST DON"T GET IT. I am looking at this science, I am listening, but the whole thing seems so ridiculously, hilariously, miraculously walking on water ridiculous to me. Yes, I will use the word ridiculous twice.

 

Apparently, I am one of those many generic unscientific Americans who look at the theory of evolution and question how "believable" it is. But it's not just me. I can't think of a single science teacher I had in public school who ever gave evolution more than a cursory nod. It was such a non-issue.

 

I wish that there was some writing for people like me--people who are willing to study and learn, but really wrestle with the whole "believability" factor."

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http://www.amazon.com/How-Whales-Walked-Into-Sea/dp/0590898302

 

I can't think of a single science teacher I had in public school who ever gave evolution more than a cursory nod. It was such a non-issue.

 

The science teachers in my PS experience didn't discuss evolution either, either because they were concerned about stirring up trouble in our heavily Baptist/fundamentalist town, or they were one of the religious folks themselves.

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how this mammal lost its legs, grew fins, etc, etc, etc, and turned into a dolphin, I JUST DON"T GET IT.

 

If you are sincerely interested, I will spend some time to explain it. But I do not want to get into an argument, and I have no interest in being tricked or cornered. I have a PhD in evolutionary ecology and have taken about 10 evolution classes and read around 3000 pages about evolution. All this was of course many moons ago. :glare: How to summarize such a massive topic would be a challenge, but I am willing. We could also do this privately, unless others are sincerely interested.

 

Ruth in NZ

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Sadly, this is the kind of media I am referring to.

 

Well, the editorial review of the book that is at Amazon summarizes it pretty well. I don't understand the problem.

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I'm interested. I am a creationist but don't quibble at all about how it was done. That is for God to know. I have never really understood the theory of evolution at all and would love to.

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If you are sincerely interested, I will spend some time to explain it. But I do not want to get into an argument, and I have no interest in being tricked or cornered. I have a PhD in evolutionary ecology and have taken about 10 evolution classes and read around 3000 pages about evolution. All this was of course many moons ago. :glare: How to summarize such a massive topic would be a challenge, but I am willing. We could also do this privately, unless others are sincerely interested.

 

Ruth in NZ

 

An argument isn't going to serve any purpose for me and I don't have enough knowledge to debate. I'm not clever enough to trick anyone about science. Getting kids to eat vegetables yes, evolution/creationism, no. :001_smile:

I genuinely want to understand.

I explained my difficulty in the OP.

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Well, first of all you probably need to throw out everything you have ever thought about evolution and start from scratch. You need to have a firm foundation in the basics before we discuss “a mammal walking into the ocean and growing fins.â€

 

 

There are a few basics that you probably already know but have never thought through the implications.

 

  1. in most species, more offspring are born than there is resources for (water, food, shelter, etc)
  2. In most environments, individuals compete for resources
  3. Some individuals have better traits than others, and they win the resources
  4. these traits are inherited. Meaning their offspring probably will have the traits also
  5. the last main point is that mutations occur in individuals

 

 

The implication of this is that individuals with more adaptive traits, have more offspring who have these adaptive traits. For example, the peppered moth in England in the 1800s had a white form and a dark form. The trees it hid on were white, so most of the individuals were white. During the industrial revolution, the coal dust coated the trees with dark dust. The white moths were now visible and the dark moths were not. The white moths were eaten, and the uneaten dark moths had more offspring that were dark.

 

 

Ok, next main point. In contrast to what most people think, evolution is defined as “the change in gene frequency in a population over time.†So what does that mean? Well, it means that to understand evolution you must understand population genetics. Genetics is the study of the individual, population genetics is the study of the ratio of different genes in the population. So how many white forms of moth were there vs dark forms and how did this change over time. Something like 100:1 changing to 1:100. So by definition, evolution occurred in this population. Population genetics gets VERY complicated because of dominant and recessive traits are seen in the population in different ways. Also, some visible traits like intelligence are coded for by many genes. Also, during process of meiosis and crossing over, genes that are more closely located on the DNA are more likely to stay together. There are many other issues that complicate the inheritance of genes, the expression of genes, and how the environment might act to remove a non-adaptive trait.

 

 

Now, for the part that most people really really don't understand intuitively. 4.5 BILLION years is a very very long time, especially for organisms with a short life span. These little tiny changes in traits (moths are now dark) occur all the time, and add up. Over many generations, populations that are divided change to such a degree that the individuals can no longer mate. For example, lets say that 2 bee populations were separated by a large distance (perhaps a glacier separated them). One population shared an environment with a wasp species that liked to pollinate the same species of flowers. Bee individuals that pollinated a different flower or pollinate the same flower at a different time would be able to get more food. With more food, those individuals could have more babies. And as long as this trait is inherited, their offspring would pollinate in the same fashion as their parents. When the glacier melts, and the 2 bee populations come back together, they will never meet. The individuals from each population are on different flowers or pollinating at different times. These 2 populations can now be categorized as separate species, because they cannot mate. Overtime, these 2 species will diverge further, because genes in each species will no longer be mixing. Mutations in each species will not pass to the other species, and because mutations are random, the other species is not likely to have the same mutations. These new mutations will continue to be acted on by the environment and will either be included or rejected from the population depending on their adaptability.

 

 

Last point, over a billion years, many changes happen, many species are formed (and go extinct). Scientists do not make some differentiation between micro and macro evolution. Evolution is just the change in gene frequencies in a population over time. It is a continuum. First there are only a few changes and the species still look similar, but over time (LOTS of time) the species will look less and less like each other.

 

 

These are the basics. Questions?

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But when I put a video on for my kids and a picture of a mammal pops up and the slow drone of the announcer tells us all (while the pictures show it) how this mammal lost its legs, grew fins, etc, etc, etc, and turned into a dolphin

 

See, and I look at a skeleton of a whale, and I see that they have 5-fingered hands with all the same bones as ours, and it seems really obvious to me that they once had limbs like terrestrial quadrupeds. :tongue_smilie:

 

One thing you've got to throw out is that they "grew fins". Their front feet/paws whatever the animal had, over time became webbed (some individuals were born with that mutation - even humans are born with webbed hands sometimes) and more of them survived. Little changes over time.

 

Look at the diversity of dogs - and they're even the same species. Long legs, short legs, pointed ears, floppy ears, long snout, short snout, long tail, no tail. There are tons of different genetic variations in our genes. In an extreme situation, some variations are favored over others and get passed on.

 

For whales/dolphins, look at all the other marine mammals that also came from land animals once upon a time. There are sea lions, who still have four articulated limbs - their rear limbs function as a tail in water, but on land can be used to walk with. Then there are seals, whose front feet have become more flipper-like but can still be used to support themselves and move around, but their rear limbs have all but disappeared or become useless on land. At one time the whales/dolphins would have been in a stage more similar to those.

 

Snakes also came from lizards. Did you know there are many species alive today in the world that look exactly like snakes but still have hind legs but have "lost" their front ones? We don't even need the fossil record to imagine intermediate steps.

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When scientists use the terms evolution and natural selection, are they talking about the same thing?

 

How do we end up with extraordinarily complex organs or systems (like the eye or the blood-clotting mechanism) or really tiny organisms that are very complicated (like a microorganism that has flagellum or cilia to propel it?)

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See, and I look at a skeleton of a whale, and I see that they have 5-fingered hands with all the same bones as ours, and it seems really obvious to me that they once had limbs like terrestrial quadrupeds. :tongue_smilie:

 

 

I don't understand why you are using the :tongue_smilie: icon. Can you help me understand what you mean?

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When scientists use the terms evolution and natural selection, are they talking about the same thing?

 

No. Evolution is the change in gene frequencies in a population over time. It can be caused by natural selection or genetic drift, and augmented by things like population bottlenecks and the founder effect.

 

Natural selection is the process I described above with inherited characteristics being selected for in the environment.

 

Genetic drift is random changes in gene frequencies. For example I have a friend who has 5 sons and a daughter. Statistically she should have 3 and 3, right? But you can flip 5 heads in a row with a coin. Chance happens. And in small populations, chance becomes very very important. If a population is founded on an island with only 10 individuals, not only will it not have all the traits that the entire population did, it is also likely to loose traits over time just by chance -- which individuals mate together, or an individual accidentally dies (the only one with a certain trait), etc. These isolated populations often speciate very quickly.

 

Natural selection and genetic drift are the 2 main processes that make changes in gene frequencies in population happen, which is evolution.

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I don't understand why you are using the :tongue_smilie: icon. Can you help me understand what you mean?

 

Just that I'm saying that with a goofy smile and trying not to sound too much like a pompous twit saying that I find something intuitive that you might not. There are plenty of things I don't find intuitive and have to puzzle through that other people find easy to grasp. When I first heard about evolution, I thought, "well, of course." I was trying to reverse-engineer what made me think that.

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How do we end up with extraordinarily complex organs or systems (like the eye or the blood-clotting mechanism) or really tiny organisms that are very complicated (like a microorganism that has flagellum or cilia to propel it?)

 

Time, lots and lots of time. I will take the eye as an example. Why do some organisms have an eye and other don't. Jellyfish don't have eyes, why not? Eyes develop in organisms that move forward in their environment, not ones that float randomly. All organisms require senses to interact with its environment - to find food, to avoid trouble etc. When an animal moves forward, its senses are focused in the front, the head, which is why it develops a brain where the jellyfish does not. The eye started as light sensor and then over time a more advanced light sensor, then a simple image collector, and then a more complex eye. Each of the steps gave an advantage to the individual with the mutation, which was then inherited by the offspring.

 

I have seen people try to argue that these complex systems do not have intermediaries so could not evolve. These systems did have intermediaries. I have seen it in the literature, but the biochemistry of the flagella papers just about did my head in.

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The definition for evolution that you've shared with me, Ruth, is very different from the one I've been unofficially carrying around in my head (and probably not just me :001_smile:) I think my "working" idea of evolution would be something like this an accidental, unguided process of genetics that ends up with organisms getting more complicated (and better) over time.

 

It is very helpful to have you define terms for me. It helps me understand.

 

Perhaps my biggest hindrance is really grasping billions of years. My "perception" of how evolution is presented by nature videos makes it feel like they are saying a mammal walks into the water and "presto!" turns into a well-designed dolphin.

 

Another thing that impacts me is how often a scientist (such as I might hear on National Public Radio or something in a video) often refers to the how well an organism is "designed." I find this confusing. The genetic process of change over time is random, but it looks designed because a given organism (or organ or system) can be so beautiful, complicated, or well-functioning? Do you understand my confusion?

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See, and I look at a skeleton of a whale, and I see that they have 5-fingered hands with all the same bones as ours, and it seems really obvious to me that they once had limbs like terrestrial quadrupeds.

 

Can you help me understand what you mean?

 

I can't speak for Matroyshka, but when I see whale fins and human hands side by side

hand1.gif

11d.gif

It seems that they contain the same bones in a very similar configuration. From there, the idea that whales and humans at one point shared an ancestor that had hands somewhere between ours and theirs doesn't seem particularly far-fetched.

 

To answer a question in another post, natural selection is the idea that not every animal can survive and therefore "selection" is occurring (ie some do not make it to reproductive age and are not selected as a mate, because they're dead and all.). Evolution is the changes based on natural selection.

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Just that I'm saying that with a goofy smile and trying not to sound too much like a pompous twit saying that I find something intuitive that you might not. There are plenty of things I don't find intuitive and have to puzzle through that other people find easy to grasp. When I first heard about evolution, I thought, "well, of course." I was trying to reverse-engineer what made me think that.

 

Thanks for letting me know what you meant. I'm glad you didn't mean derision toward me for finding the idea I described hard to believe. Typing doesn't convey emotions well, does it? I think I've experienced more frustration over trying to understand the "tongue in cheek emoticon" more than any other symbol on the forum.

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Perhaps my biggest hindrance is really grasping billions of years. My "perception" of how evolution is presented by nature videos makes it feel like they are saying a mammal walks into the water and "presto!" turns into a well-designed dolphin.

That book to which you linked sounds like it might really help, in showing the transitional forms from the fossil record that we know about so far. I know what you mean about having difficulty in grasping the scope of time involved, though. (And if you happen to have bought that book and want to unload your copy, I might consider buying it... it's sadly out of print and looks good!)

 

Another thing that impacts me is how often a scientist (such as I might hear on National Public Radio or something in a video) often refers to the how well an organism is "designed." I find this confusing. The genetic process of change over time is random, but it looks designed because a given organism (or organ or system) can be so beautiful, complicated, or well-functioning? Do you understand my confusion?

In the past, with a particular science resource (it might have been Ellen McHenry materials) discussed I believe on this site, I recall that some people were up in arms over what they felt were hints at Intelligent Design being presented. It turned out that most such references had been removed, and only one use of the word "design" was left. Someone thoughtfully remarked that scientists sometimes (often?) may use this word to mean "fit of form to function" or something similar, without meaning to imply the hand of a supernatural designer. It made sense to me.

 

I think my "working" idea of evolution would be something like this an accidental, unguided process of genetics that ends up with organisms getting more complicated (and better) over time.

I guess with genetic drift as explained above by lewelma, the organisms aren't guaranteed to get better in any particular way. I think that the "accidental, unguided" idea is what gives so many people difficulties. I guess it is accidental in some sense, as mutations are fairly random and the selection out of less-fit individuals also depends on some occurrences that on an individual level can seem fairly random: a particular prey animal without an adaptation to make it faster wanders into the path of a particular predator that's able to catch it, etc. I don't think of those things as unguided, though-- they are guided by the environment in which the species finds itself. If the climate gets colder over 100,000 years, then the individuals with thicker fur will survive to procreation more often, or if a predator species develops more speed, then over time enough of those chance run-ins will happen to weed out the slow prey animals. KWIM?

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Perhaps my biggest hindrance is really grasping billions of years. My "perception" of how evolution is presented by nature videos makes it feel like they are saying a mammal walks into the water and "presto!" turns into a well-designed dolphin.

 

Another thing that impacts me is how often a scientist (such as I might hear on National Public Radio or something in a video) often refers to the how well an organism is "designed." I find this confusing. The genetic process of change over time is random, but it looks designed because a given organism (or organ or system) can be so beautiful, complicated, or well-functioning? Do you understand my confusion?

 

I totally understand this one. We are watching "Walking with Monsters" and the announcer talked about fish learning to escape the arthropods by growing legs and moving to land. I commented to dh about how it's not like the fish said, "Oh no, we;re being chased! Better grow legs now and run away!" :lol:

 

As for the last paragraph, well, I'm a theistic evolutionist so I do believe all things on Earth were indeed "designed" and that evolution is the process by which they were made. Others who believe differently will have different answers for you.

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I totally understand this one. We are watching "Walking with Dinosaurs" and the announcer talked about fish learning to escape the arthropods by growing legs and moving to land. I commented to dh about how it's not like the fish said, "Oh no, we;re being chased! Better grow legs now and run away!" :lol:

 

:iagree: There. You have done it for me---this is exactly what I am referring to.

 

Now, how many of us are there that have the same problem. How many SCIENCE teachers share this problem?

 

Scientists may be totally correct in their understanding of how organisms change over time, but they are having trouble convincing a skeptical public.

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:iagree: There. You have done it for me---this is exactly what I am referring to.

 

Now, how many of us are there that have the same problem. How many SCIENCE teachers share this problem?

 

Scientists may be totally correct in their understanding of how organisms change over time, but they are having trouble convincing a skeptical public.

 

I think they need to use more phrases like "over many generations"

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I can't speak for Matroyshka, but when I see whale fins and human hands side by side

hand1.gif

11d.gif

It seems that they contain the same bones in a very similar configuration. From there, the idea that whales and humans at one point shared an ancestor that had hands somewhere between ours and theirs doesn't seem particularly far-fetched.

 

To answer a question in another post, natural selection is the idea that not every animal can survive and therefore "selection" is occurring (ie some do not make it to reproductive age and are not selected as a mate, because they're dead and all.). Evolution is the changes based on natural selection.

 

To Carp E or Ruth--so there is only ONE common ancestor? Could five digits develop by evolution in different organisms in different places on the globe?

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I think my "working" idea of evolution would be something like this an accidental, unguided process of genetics that ends up with organisms getting more complicated (and better) over time.

 

First of all, definitely NOT more complicated over time, just better adapted. Viruses and bacteria are very adapted to their environments and are not complex. The extremophiles living the the deep sea hot vents are amazingly adapted. Also, keep in mind that being adapted is a moving target because every environment changes. For a small organism like a snail, if a large tree fell in the woods and created a hole in the canope, the ground below it would begin to dry out and become a harsher climate for the snail. If the hole was large enough compared to the range of the organism, and the organism could not escape this hostile environment, then all of it's adaptations would no longer be useful. Natural selection would begin to work on variability in the population. And remember that all populations have variability (we are not all identical twins) and the more variability the better (which is why most organisms in variable environments prefer sexual selection to asexual selection because it increases the variability expressed in the population because of crossing over). When there is more variability, natural selection has "more to work with" to select for better adapted animals.

 

Point 2, not always better. Did you ever wonder why humans have some really terrible, rare, diseases like Cystic Fibrosis. I am not sure how well I can explain this because it is complicated but here it goes. Recessive traits are very difficult to remove from a population through natural selection. Natural selection can only work on what is expressed, and recessive traits are only expressed if a person gets one from the mom and from the dad. In the past few individuals with CF would have lived long enough to have children, so the gene would not be passed to the next generation. This happens over and over and drives the CF trait close to 0 in frequency. But here is the problem, the gene is not GONE in the population, and is hiding recessively in a few individuals. It is only expressed when 2 individuals with these hidden recessive traits have a baby, and then only 1 in 4 children will have it and 2 of the 4 others will be carriers by chance. But more often the recessive trait is not expressed and is passed to the next generation in individuals who are carriers. So natural selection cannot get rid of this trait in the population even though it is such a bad trait.

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To Carp E or Ruth--so there is only ONE common ancestor? Could five digits develop by evolution in different organisms in different places on the globe?

 

Eventually yes there is one common ancestor. Before there were people and whales there was the first mammal that evolved from reptiles (? I'm not an expert) and before reptiles, amphibians, and before them fish, and before them whatever it was that's prefish. LOL. Sorry. Not an expert like I said. Eventually you get back to micro-organisms and eventually the very first life. But what that very first life was is arbitrary, we drew a line and said something must be this complex to be alive. But the first life evolved out of things that were increasingly complex, starting with a single self-replicating protein.

 

But on that note, sure it's possible for animals to evolve the same complex systems in isolation, it's just very improbable, and we haven't found evidence of it (yet?).

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so there is only ONE common ancestor? Could five digits develop by evolution in different organisms in different places on the globe?

 

No, not ONE individual. Yes, 1 shared common ancestor species.

 

Convergent evolution is when the environment selects for similar traits. But these traits look different because natural selection was acting on different variability. Bird's wing vs Bat's wings. Shark's body shape vs Dolphin's body shape. squid eye vs vertebrate eye. You can tell these are convergent evolution and not derived from a common ancestor species because the physiology of the body parts is different.

 

You could definitely have 5 fingers evolve twice independently, but they would look different on the "inside."

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Another thing that impacts me is how often a scientist (such as I might hear on National Public Radio or something in a video) often refers to the how well an organism is "designed." I find this confusing. The genetic process of change over time is random, but it looks designed because a given organism (or organ or system) can be so beautiful, complicated, or well-functioning? Do you understand my confusion?

 

 

When you hear "designed" think "selected for." Natural selection is not random. It works on the available variability to select for more adapted traits, which is why species look "designed" for their environment.

 

Genetic drift and mutation are the random elements in evolution.

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Lewelma and Carpe, I think you are doing an excellent job explaining evolution.

 

If I may make a recommendation to the OP and others sincerely looking to understand the theory, Evolution by Daniel Loxton does a great job, IMO. It's really not just for kids.

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Scientists may be totally correct in their understanding of how organisms change over time, but they are having trouble convincing a skeptical public.

 

you might be interested to know that this is not true in other countries.

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When you hear "designed" think "selected for." Natural selection is not random. It works on the available variability to select for more adapted traits, which is why species look "designed" for their environment.

 

Genetic drift and mutation are the random elements in evolution.

 

I think I need more information on natural selection. Even the word selection can seem to have the connotation that "someone" is doing the selecting.

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I think I need more information on natural selection. Even the word selection can seem to have the connotation that "someone" is doing the selecting.

 

Someone is doing the selection, either mates or predators. Predators are saying you're delicious and eating them before they mate, or potential mates are saying you are fantastic I want your babies. LOL.

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I think I need more information on natural selection. Even the word selection can seem to have the connotation that "someone" is doing the selecting.

 

In my experience, difficult concepts take some time to sink in. You need to reread my first post over and over for about 3 weeks and you will gain insight.

 

When a trait is "selected" that means that the individual with the beneficial trait gains more resources and has more offspring who carry that trait. Think of it as the environment doing the selecting.

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Here is a graph of belief in evolution by country. The US is way down at the bottom.

 

http://www.nytimes.com/imagepages/2006/08/14/science/sciencespecial2/20050815_EVO_GRAPHIC.html

 

For the next link if you scroll down, there is a graphic of belief in evolution by religious affiliation

 

http://en.wikipedia.org/wiki/Level_of_support_for_evolution

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I totally understand this one. We are watching "Walking with Monsters" and the announcer talked about fish learning to escape the arthropods by growing legs and moving to land. I commented to dh about how it's not like the fish said, "Oh no, we;re being chased! Better grow legs now and run away!" :lol:

 

As a science educator, I REALLY dislike the "Walking with" videos. In an effort to make the videos entertaining, they mingle science with imagination, and then present it as fact. As a video producer, I love their animation, but I have to turn off the sound to enjoy the program.

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As a science educator, I REALLY dislike the "Walking with" videos. In an effort to make the videos entertaining, they mingle science with imagination, and then present it as fact. As a video producer, I love their animation, but I have to turn off the sound to enjoy the program.

 

Agreed. In my defense, I wasn't the one who picked it to watch. :lol: I prefer a good Bill Nye (or Happy Scientist).

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Someone is doing the selection, either mates or predators. Predators are saying you're delicious and eating them before they mate, or potential mates are saying you are fantastic I want your babies. LOL.

:lol:

My favorite science event this year was the care and keeping of a praying mantis my curious 5yo found in the back yard. He watched over and fed said praying mantis for weeks. Weeks, I tell you! One day on our way to church we noticed that another mantis was sitting on the butterfly cage, trying to get inside. We put the second mantis in the cage, zipped it up, and went to church.

When we got home, imagine the joy, the yells of fun, when ds discovered the insects. "Mom, they're hugging!!!" Oh, my. We go inside, watch some informative videos on the mating of praying mantises.

We went back outside and Mr. Manty was gone. Yep. She ate him.

Then for 3 hours she squeezed a thousand eggs into her egg case.

My five year old loves to explain things that he's just learned. I don't think all the neighborhood kids were quite ready....

 

Natural Selection. At its best.

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I just don't understand the WHY. The driving force behind it, KWIM??

 

Don't think of a "driving force". There is natural variability in population of organisms. There are limited resources. Some individuals will be better able to get the resources and they will have more babies which have this adaptive trait. That is it! Don't overcomplicate it.

 

Like, WHY did that first protein split.
Chance. proteins are not alive so they can't be acted on by natural selection. Natural selection requires that adaptive traits are inherited by babies.

 

WHY did the fish eventually grow legs to run away? What force was behind that?

 

The individuals who could leave the water for even a little time to collect food, did not have to compete for food in the busy ocean. These individuals had more offspring, who had the trait for moving onto land. This process occurred over millions of years one baby step at a time.

 

 

What made the fish WANT to live as opposed to just getting eaten?
It didn't. But the fish that could escape, had more babies that then could escape. The fish that was eaten did not have any babies so the population of fish over time lost the gene for sitting still and getting eaten.

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Reading these two books really helped me get a better grasp on evolution. As a non-science-y person, I really enjoyed both!

 

http://www.amazon.com/Evolution-How-Living-Things-Came/dp/1554534305/ref=sr_1_3?s=books&ie=UTF8&qid=1328490045&sr=1-3

 

http://www.amazon.com/Magic-Reality-Know-Whats-Really/dp/1439192812/ref=sr_1_1?s=books&ie=UTF8&qid=1328490129&sr=1-1

 

We also watched this on netflix, which was similar in theme to the books.

 

http://movies.netflix.com/WiMovie/Ape_to_Man/70040032?trkid=496624

 

I'd be curious if the science-minded folk in this thread (Robert?) would say these are decent resources? My kids even enjoyed them.

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Y

I just don't understand the WHY. The driving force behind it, KWIM?? Like, WHY did that first protein split.

 

Two different things - in an already complex organism, there is diversity in the genes. Like the dog example again.

 

Then there's mutation. There's replication error. Every time a cell divides, the DNA is replicated for each daughter cell. Sometimes there's an error. This also happens in meiosis, then a trait not shared by either parent can be had by a child (I personally have one of these. It's not beneficial, but neither particularly harmful. But it is a mutation that neither of my parents have, which I have now passed to all three of my children - it's a dominant gene :glare:).

 

Mutation can also happen from things like radiation damaging the DNA.

 

WHY did the fish eventually grow legs to run away? What force was behind that? What made the fish WANT to live as opposed to just getting eaten?

 

There is no question of will. The fish that has an adaptation (through recessive gene expression or through mutation) that can manage not to be eaten will live to pass on their genes. The one who gets eaten will not.

 

I just don't get/understand why the environment is given omniscience... does that make sense??

 

The environment is not omniscent. It is not sentient at all. Plenty of catastrophes wipe out entire populations - no one survives to pass on their genes. Look at the dinosaurs. But again - look at the dinosaurs. Some that were smaller and could live on less and had feathers for insulation (yes, some dinosaurs had feathers - it's in the fossil record) were able to more easily adapt to the environmental damage after the meteor hit (think that's still the current explanation), and eventually became birds. It's just a matter of who survives to pass on their genes, and who doesn't.

 

And if the environment is the only one doing the selecting, then why is this only happening on our planet? Why isn't there life on neighboring planets that has adapted to it's own environment?

 

Because there's no life there to adapt. If there were life, I'm sure it would. Why is there no life there? Too hot, too cold, no atmosphere, not the right combination of building blocks? - no one knows for sure. We can only speculate. Some scientists still hold out a slim hope of finding life on Mars. If there were ever any life there, and if there was still some microbial remnant of it, it would have had adapt extremely to still survive from the time when Mars had much more atmosphere and was warmer and conditions for potential life more welcoming (for lack of a better word popping in to my head).

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I just don't get/understand why the environment is given omniscience... does that make sense??

 

I'm not a scientist, but I will ask you why you believe that anyone is giving the environment omniscience. The environment doesn't THINK anything or PLAN anything. These things just happen. Do you believe that the environment plans on the shifting of the continents or that it just happens over time? Why do random events suggest that the environment (a non-living thing) is somehow possessed of infinite knowledge? I don't understand the question.

 

And if the environment is the only one doing the selecting, then why is this only happening on our planet? Why isn't there life on neighboring planets that has adapted to it's own environment?
Because if life is a completely random, one-in-a-billion occurrence, then there's no reason that we should find it everywhere. Actually, it would seem to me that this sort of question would be better posed to creationists. Why would a god put life ONLY on this planet? What's the reason for that? If it's all on purpose, all for a reason, all so God wouldn't be lonely, why not make lots and lots and lots of life, all over the solar system? It makes a lot more sense that life would be uncommon if there isn't a god than if there is, IMO.

 

Editing, because that wasn't really clear: Or, don't make it about God. I'm not even an atheist (agnostic - don't know if there's a god, don't worry about it). Rather, make it about a plan. It would make more sense if there were no specific plan for life that life would be rare, IMO. If there is a plan for life, if it were designed to serve the purpose of keeping God company or making someone to love God, then why make life so rare in the solar system? Why not make lots and lots of life, so that there would be a greater chance of success? More company, more adulation, more worship, whatever.

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I just don't get/understand why the environment is given omniscience... does that make sense??

 

it is not. But the environment does kill less adaptive individuals, thus removing their genes from the population. removal of genes from the population changes the gene frequencies in the population, which by definition is evolution.

 

And if the environment is the only one doing the selecting, then why is this only happening on our planet? Why isn't there life on neighboring planets that has adapted to it's own environment?
We don't know that there is no life on other nearby planets. Europa (moon of Jupiter) likely has liquid water and likely has life IMHO. One of the things that makes earth special is the spinning core creates a magnetic field around the earth which protects us from the solar wind.

 

ETA As far as I am concerned there is definitely life on distant planets. Even with a 1 in a billion chance, there are trillions of stars and planets. very straight forward math.

 

Do evolutionary scientists have a theory for what the driving force is?
There is no driving force, which is often what bothers people.

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Ruth in NZ, thank you so much for your patience with me and for you time.

 

Thanks, all, for those considerate questions, careful answers, and for reading thoughtfully in a way to listen to one another. If you want to pick an evolution/creation fight, I think there is another thread here that would suit you better than this one. :001_smile:

 

I will check back in later, but I'm going to put some kiddos to bed now.

Apparently the Super Bowl in on TV in the US--but then how is that so many of us are here learning about evolutionary biology?

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I'm a former scientist, too. I think one of the reasons people find it so difficult to understand evolution is because there is much talk of species "adapting to their environments". They don't really adapt in the way we traditionally use the term. The environment gives some advantage to certain traits. Through a serious of random mutations and the like (as detailed by Ruth), the environment weeds out those not suitable, and over time, weeds out their genes. Giraffes didn't grow long necks so they could eat leaves on tall trees. Those giraffes who had longer than normal necks got more chances to eat and thus were better able to breed and pass on their long-necked genes. Then, when there came a time when lower growing food species were scarce, the long necked giraffes were OK and the short necked giraffes had no food and died off. Voila, evolutionary advantage.

 

There is no omnipotence involved in evolution. The driving force is survival, which really means passing on one's genes. Evolution is much slower when there is no pressure on the individual before mating occurs. For example, as someone with fair skin, I am very poorly suited to the country I live in (Australia). I burn and am at high risk of skin cancer. However, skin cancer usually occurs after child-bearing, so I am able to pass on my poorly suited, fair genes to the next generation of sunscreen purchasers. It will thus take a jolly long time (or a savage increase in global warming and UV radiation) before Australian skin starts to more closely resemble the very well adapted skin of the Australian Aborigines again.

 

I hope this helps and doesn't just muddy the waters.......

D

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Ruth in NZ, thank you so much for your patience with me and for you time.

 

Glad to help. I'm off to the grocery store, be back later. You are lucky you caught me today because it is Monday and I am usually teaching.... but today is a public holiday, Waitangi day, the celebration of the treaty between the original inhabitants of NZ and the British.

 

I'm so glad that this thread was not argumentative!

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I often wonder about the giraffe example.

 

Why not also see evidence of "short necked giraffes" that migrated to other areas if their diets depended on the availability of having certain plants for food?

 

Is this where any explanation given would point to the "randomness" of it all?

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Yes, thank you all very much for such an informative thread. And I, also, would be interested to know if the books tammyw suggested are recommended by the science-minded folks. Or any other recommended books would be appreciated. For some reason I always just accepted evolution. But I have no idea why. I certainly couldn't have verbalized it. That's scarey! Now I need information to back up my beliefs.

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I often wonder about the giraffe example.

 

Why not also see evidence of "short necked giraffes" that migrated to other areas if their diets depended on the availability of having certain plants for food?

 

Is this where any explanation given would point to the "randomness" of it all?

Like the Okapi? It's the giraffe's closest living relative.

 

Okapi.jpg

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Yes, thank you all very much for such an informative thread. And I, also, would be interested to know if the books tammyw suggested are recommended by the science-minded folks. Or any other recommended books would be appreciated. For some reason I always just accepted evolution. But I have no idea why. I certainly couldn't have verbalized it. That's scarey! Now I need information to back up my beliefs.
I posted this on another thread, but here's a good list to start:

 

Any of these books would provide a good start in understanding evolution (links to amazon pages in url) :

http://skepchick.org/2012/01/ask-surly-amy-evolution-books/

 

Books on Evolution

 

1. Charles Darwin on the Origin of Species – The Illustrated Edition (It really is a beautiful book.)

 

2. Why Evolution Is True by Jerry Coyne (This was the number one most recommended books of the people I polled.)

 

3. The Beak of the Finch by Jonathan Weiner (This one also had a LOT of recommendations.)

 

4. At the Water’s Edge by Carl Zimmer.

 

5. Almost Like A Whale by Steve Jones.

 

6. Your Inner Fish by Neil Shubin (Also highly recommended.)

 

7. The Rough Guide to Evolution by Mark Pallen

 

8. The Tangled Bank by Carl Zimmer

 

9. Evolution: How We and All Living Things Came to Be by Daniel Loxton

 

10. Science On Trial by Douglas J. Futuyma

 

11. Evolution: The Story of Life on Earth by Jay Hosler

 

12. For the religious: Coming To Peace With Science by Darrel Falk.

 

13. Introducing Evolution: A Graphic Guide, by Dylan Evans & Howard Selina.

 

14. Evolution: What The Fossils Say And Why It Matters. by Donald Prothero

 

15. What Evolution Is by Ernest Mayr

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