Calling Cofty and others regarding evolution

by dubstepped 340 Replies latest jw friends

  • dubstepped

    @Anders Anderson - Thanks for the book recommendations, in order. I'll see what's available in audio format. I have "Why Evolution Is True" in my wishlist on Amazon for the audio book but audio is more expensive and I was hesitant to pull the trigger. The same person that recommended it recommended the one I bought that wasn't so great.

  • OnTheWayOut

    I will answer as the amateur I am, and hopefully provide simple answers to the complicated subject you choose to tackle.

    First of all, monkeys did not evolve into humans. Not even a portion of the monkeys in some isolated area of Africa. Monkeys and humans have a common ancestor. It's a huge difference. Each branch of the evolutionary chain adapted to survive in its own way. Similarly, humans are on one branch and various monkey species are several different branches.

    Asking "why are there still....." questions suggests that it is all linear. Perhaps the presentations of evolution cause many to believe that. There is no single family of a species in existence with one set of parents. Maybe an easy way to understand this is to say that "If Asians followed the bison across the dry land of the Bering Straits, why are there still Asians in Asia?" We can all clearly understand that they didn't all go that way. (...and forgive me if that theory is not the accepted one anymore.)

    Such questions as "Why are there still monkeys?" or "Why don't we see new species arriving today?" are creationist zinger questions. Ones they ask to stump people. There are answers, but since the answers cannot be framed in a single statement as the question was, they quickly shout "Checkmate, atheists!" and don't do the work of understanding the answer.


    As far as seeing macro evolution today, it's not like you could watch an old black and white movie from the 1920's and then another from the 21st century and note that the humans are different. It takes a wee bit more than your lifetime for changes to occur.

    And further, as far as man is concerned, modern interactions interfere with "speciation," the evolutionary process by which populations evolve to become distinct species. If the Aborigines or the Japanese or any group on the planet remained isolated for several generations (granted, an amatuer like me doesn't know how many generations) then it would be likely that they could no longer produce offspring with outsiders because they finally became genetically different.

    To take that to the animals, it does happen. But we don't see it easily because of the "several generations" things. Most hybrids of animals produce sterile offspring and don't allow for the creation of entirely different branches of the tree- think of the horse and donkey producing a mule; mules are sterile. But sometimes, speciation occurs and we have seen the results. Read up on the Galopogos Finch and see that it has occured. Even though many will say they are all still finches, apparently there are some different ones that cannot interbreed. So each will adapt separately and follow its own evolution.

    And keep in mind that just as humans interfere with their own evolution by not staying isolated, humans also interfere with the evolution of animals. We give less and less space to wildlife and keep the land for ourselves. There is less and less chance that portions of a species will be isolated.

    But if you are interested in seeing speciation in life that is a bit less complicated than animals, there are flowers and other plants that have been documented to evolve a bit quicker into separate species.

    Experts, feel free to tear apart my layman's understanding. Otherwise, I hope it helps.

  • TD

    IMHO, the most common pitfall is trying to gulp down the whole camel at once as opposed to understanding the building blocks of the theory one at a time.

    It's obvious that some species are closely related to others. Sheep and goats have been successfully paired (It is very rare, but it has happened) So have Camels and llamas.

    Lions and tigers can produce offspring. So can jaguars and leopards. So can tigers and leopards. So can pumas and leopards. It should therefore be intuitively apparent that the big cats spring from a common ancestor.

    It's equally obvious that these species have drifted genetically. Male offspring of these unions are almost always sterile.

    The cheetah has drifted to the point of reproductive isolation. Although it is clearly a member of family Felidae, it cannot be successfully paired with any other member. At this point, the biblical notion of "kinds" goes out the window, inasmuch as it is defined by reproduction, not taxonomy.

    We have a very similar situation with dogs. Family Canidae is a large group with many members, but they can't all reproduce with each other. Some, like the racoon dog, for example have drifted into reproductive isolation.

    How far does genetic drift go? If you can accept that the dog, racoon and bear all had a common ancestor, then you've digested a major building block of evolutionary theory.

    In response to this, proponents of creation will guffaw and say that these animals are all variations on basically the same theme. They're all four legged, warm blooded carnivores and not really anything, "new."

    However that's another basic building block of the theory. Evolution works on what is already there. A mammal with six limbs would positively destroy the theory because the four limb configuration emerged long before mammals themselves did. Unlike an intelligent designer, who can design an electric motor one day and an internal combustion engine the next, it can't go back to the drawing board like that.

  • cofty

    Hi dubstepped. Sorry if I am repeating stuff that has already been covered above.

    Prothero very much focuses on the evidence for evolution from paleontology. He begins by defending his field from the false accusations made by creationists regarding the geological column and dating methods. It is full of great information - he has released a new volume recently - but for an introduction to biological evolution it's not a great choice.

    The book list suggested by Anders is excellent but I would add "The Blind Watchmaker" by Dawkins.

    I thought he was supposed to go into the primordial soup but he never even mentioned it.

    Very few books on evolution also deal with the origin of life. Abiogenesis is a distinct field of study. There is some really good work being done at UCL (London) by Nick Lane and his team that is approaching the problem via bioenergetics. In other words where did the energy come from to fuel the transition from geochemistry to biochemistry? "Organic soup" is not a likely candidate. Creationists are not wrong when they say that you can spark a can of soup as long as you like but you will never get life. If you want to look further into this topic Nick Lane's "The Vital Question" is extremely interesting. Alternatively you could get "Life Arising" by the same author where you will get one chapter on this topic and nine on other fascinating aspects of evolution.

    What I gather is that there are two types of evolution, micro and macro

    These are not really phrases that would be used by most biologists. Changes in the frequency of particular versions of genes -alleles - accumulate over time. Deciding when micro becomes macro is very subjective. Obviously when a population has changed sufficiently that they can no longer interbreed with the parent species then an important line has been crossed. That can be a subtle as the difference between Herring Gulls and Lesser Black-backed Gulls or as startling as the gap between chimps and humans. It's all the same mechanisms at play.

    Such evolution occurs due to environmental pressures or maybe some part of dna changing through reproduction. It is more likely to occur somewhere like on an island that is more isolated and where a change in one progeny is less likely to breed out due to a large population.

    Yes. The key thing to remember is that nothing ever adapts to its environment. Rather a variety of genetic variation exists within a gene-pool. When changes happen in an environment in an isolated breeding group then some of those variations will confer a slight advantage. The frequency of that mutation will then become more common - or even ubiquitous - in that population.

    Unlike the linear way that evolution was presented to us where an amphibian turns into a mammal that turns into a monkey and eventually a human (I butchered that), there were slight changes over time in chimps over time that led to us. There is only a small difference in dna between us and a chimp.

    Just to clarify we and chimps both evolved from a common ancestor about 6 million years ago. Both lineages have been changing since then. The genetic difference is now about 1.5% but that means that our genome has only changed by about half that amount in that time.

    I just can't seem to grasp how those different species evolved in the first place. I see that birds can evolve to have different characteristics, but are birds still evolving in a macro way into something as different as a dolphin is from a bird? Or if such a small genetic change as there is between a chip and a human creates such different creatures (we are quite different than a chimp even with 99% similarity in DNA), then why don't we see other large changes like that more?

    Three things to sort out here. One is that a change of just a few percent in a genome is still an awful lot of changes. We have three billion base pairs in our genome. Most mutations happen in the non-coding region and has a neutral effect.

    The other thing is to think about the genome more like a chemical formula or a recipe than a blueprint. A small change in a blueprint results in a small change in the building. A tiny change in chemical formula can have a radical change in the end result - be that a chemical compound or a sponge cake. Genes that build amino acids - that join up to build proteins - are unlikely to change much or often. There are lots of ways to make proteins that don't work but not so easy to make alternative ways to make ones that work better. However a significant part of genome are more like switches that turn on and off the production of proteins. A change in these parts of our genome can produce novel innovations. Think of it like the instructions for producing origami models. One change in the routine can make a real difference. In the nine months we were forming in the womb, cascades of genetic switches were turning on and off sculpting the embryo. This area of evolution is referred to as evolutionary developmental biology or 'evo-devo'. The most accessible books on this are by Sean B. Carroll (the biologist not the physicist by the same name) For example "Endless Forms Most Beautiful" and "The Making of thE Fittest".

    The third point I want to make is about selective pressure. Life has evolved over millions of years to fill every possible niche on the planet. Having refined their design by natural selection there just isn't a strong pressure on most species to change. Some species look identical in the fossil record as their extant descendants. Remember evolution only cares about passing on genes. If our design is good enough to leave behind viable offspring its job is done. We might want to evolve the ability to run like a cheetah but evolution can't do it unless that increases our ability to find a mate and breed. That is also why we get so many genetic illnesses in old age. There is no evolutionary pressure to eradicate those from the gene-pool.

    I hope that helps a little. Please feel free to ask more questions. It's really refreshing to see sincere questions about evolution for a change.

  • dubstepped

    Yes! Thank you Cofty for going through my posts and breaking it down bit by bit. That's exactly what I was looking for. I'm at work now but I read through it and that's what I needed. I'll get deeper in later when I get home and see if it sparks any other questions but I can already tell that you cleared some things up. Instead of merely expressing your paradigm you jumped into mine head first and started there. Awesome!

  • MeanMrMustard
  • jp1692

    Here is an excellent video that explains how “micro” becomes “macro” while deconstructing the incorrect idea that there was ever a first human:

    There Was No First Human (PBS)

  • Searril

    How far does genetic drift go? If you can accept that the dog, racoon and bear all had a common ancestor, then you've digested a major building block of evolutionary theory.

    In response to this, proponents of creation will guffaw and say that these animals are all variations on basically the same theme. They're all four legged, warm blooded carnivores and not really anything, "new."

    I just wanted to say that this is not strictly true. While I do agree you will find a large portion of creationists (especially the older ones) who will immediately disregard any of this, there are more creationists than you think who are like me. I am a creationist and a staunch evolutionist. I see nothing about one that precludes the other.

  • Diogenesister
    Dubby Macro would occur when new species evolve.

    I believe that's called Speciation.

    It sounds like you would like some specifically scientific books. Perhaps a university undergraduate course on evolutionary biology's recommended reading list or coursework books would be a good place to start?

    I love a book called " Your inner Fish"by Neil Shubin. Its Just a fun layman's book, though.

  • cofty
    I am a creationist and a staunch evolutionist. I see nothing about one that precludes the other. - Searill

    I'm interested in how you reconcile the two. Do you resort to supernatural solutions to difficult design challenges or do you adhere carefully to methodological naturalism?

Share this