Kristenaty Posted February 9, 2012 Share Posted February 9, 2012 Thank you, thank you, thank you for these answers. They have been so interesting. I've always understood basic natural selection, but I've never understood why we haven't seemed to see evolution in our own time in larger animals. I remember the Darwin moth example from high school and I get bacteria changing. Do larger animals need more time to change, or has there been no impetus for them to change because the environment has been relatively stable for . . . many years? Again, thank you so much for your answers. These have really helped to clarify my thinking. Quote Link to comment Share on other sites More sharing options...
jenangelcat Posted February 9, 2012 Share Posted February 9, 2012 Thank you, thank you, thank you for these answers. They have been so interesting. I've always understood basic natural selection, but I've never understood why we haven't seemed to see evolution in our own time in larger animals. I remember the Darwin moth example from high school and I get bacteria changing. Do larger animals need more time to change, or has there been no impetus for them to change because the environment has been relatively stable for . . . many years? Again, thank you so much for your answers. These have really helped to clarify my thinking. It takes larger animals longer to reach reproductive age. That's why we talk about generations in evolution and not years. Quote Link to comment Share on other sites More sharing options...
lewelma Posted February 9, 2012 Share Posted February 9, 2012 Do larger animals need more time to change, or has there been no impetus for them to change because the environment has been relatively stable for . . . many years? It takes larger animals longer to reach reproductive age. That's why we talk about generations in evolution and not years. For slow, gradual evolution to create a new species you need about 10,000 generations (obviously this is just a very round figure). This is A LOT of generations. With very strong selective pressures it would take many fewer generations, and you might even be able to get down to 500 generations. But with the 10-year generations of most larger animals, you are still looking at 5000 years. The evolution of dog breeds is easy to see because it has happened within human written records. Dogs have evolved very quickly because of the very strong selection created by humans breeding the animals. And although dogs are considered a single species still, we are approaching the point where they soon will not be. I doubt very seriously that my younger sister's 8 pound female dog could effectively mate with my older sister's 250 pound male Mastiff. Not only do they have a problem with the machinery of mating :001_huh:, I think that the fetus would likely kill the tiny female dog. Quote Link to comment Share on other sites More sharing options...
Chrysalis Academy Posted May 1, 2013 Share Posted May 1, 2013 :001_wub: love this thread. Bumping/subbing. Quote Link to comment Share on other sites More sharing options...
Dicentra Posted May 1, 2013 Share Posted May 1, 2013 :001_wub: love this thread. Bumping/subbing. :iagree: I just finished the thread. I think I have a science-crush on Lewelma. :blush: :D Quote Link to comment Share on other sites More sharing options...
WishboneDawn Posted May 1, 2013 Share Posted May 1, 2013 nm Didn't look at the date on the thread. :D Quote Link to comment Share on other sites More sharing options...
dirty ethel rackham Posted May 2, 2013 Share Posted May 2, 2013 nm Didn't look at the date on the thread. :D I want to thank you for posting on this thread because I missed it when it first appeared. I have learned so much. My oldest son wants to be an evolutionary biologist. I think I will have him read this! Quote Link to comment Share on other sites More sharing options...
sandst Posted May 3, 2013 Share Posted May 3, 2013 Bumping Quote Link to comment Share on other sites More sharing options...
Jen in NY Posted May 3, 2013 Share Posted May 3, 2013 What a great thread! I love it. Have you all seen the HHMI Holiday Lectures on Evolution? http://www.hhmi.org/...tive/evolution/ Over the years we have enjoyed many HHMI Holiday Lectures (on DVD - they will send them all to you for free!) - now all streamable from the website. Really interesting, in depth treatments of many science topics. Try hovering over the "Topics" tab and you will see a menu of all that is available. Each HL Series we have seen consists of 3 long "lecture" segments, animations, interviews with the presenters, Q&A with the attending students, and probably more that I am not remembering at the moment. Good, good stuff. Quote Link to comment Share on other sites More sharing options...
Leav97 Posted May 3, 2013 Share Posted May 3, 2013 ... Also, no questions about societal issues: how evolution works in antibiotic resistant strains, the new flu vaccine every year, or genetically engineered organisms. And no questions about the implication of modern medicine in human evolution, the possible success of eugenics, or even the implication of small population size (bottlenecks) to the evolution of endangered species. ... Ruth A long these lines, what impact does global travel have on evolution. World travel has populations meet and breed that wouldn't have meet 1,000 years ago. What's the end result for evolution? Quote Link to comment Share on other sites More sharing options...
lewelma Posted May 3, 2013 Share Posted May 3, 2013 Because all groups of humans can mate and have viable and fertile offspring, humans are one species by definition. This means that there has always been enough migration to maintain a single gene pool. Even in the case of the lack of mixing between the old and new world for millennia, there was not enough time for random changes to accumulate and the environments were not different enough for natural selection to select for different traits, so there was no physiological problem to mating when the 2 groups re-met. Thus, the gene pools remixed very rapidly through mating. There are obviously groups of humans who have a larger ratio of one allele over another, such as skin colour. With more migration (global travel), the differences between these groups will reduce as is already occurring. Quote Link to comment Share on other sites More sharing options...
Happygrl Posted May 18, 2013 Share Posted May 18, 2013 This was an incredible thread. I just finished reading it, added several books to my to-read list and need to mull all of this around in my mind. I tried searching but couldn't find anything....have there been any similar threads (as in smart discussion) about the origins of life? Quote Link to comment Share on other sites More sharing options...
lewelma Posted May 19, 2013 Share Posted May 19, 2013 have there been any similar threads (as in smart discussion) about the origins of life? Not that I am aware of. Quote Link to comment Share on other sites More sharing options...
mysticmomma Posted May 19, 2013 Share Posted May 19, 2013 What a great thread Quote Link to comment Share on other sites More sharing options...
kaymom Posted May 19, 2013 Share Posted May 19, 2013 I am a Christian, but enjoyed the education about evolution. I still believe that God created it all, but I also believe that the creation has evolved over time. It was nice to read a thoughtful discussion. Quote Link to comment Share on other sites More sharing options...
sagira Posted May 19, 2013 Share Posted May 19, 2013 What a thread! I started reading and couldn't stop. Thank you, Lewelma, for making it so clear. Just from your beginning explanation, I could gather what you were saying. The rest was expanding the topic and icing on the cake for me! Quote Link to comment Share on other sites More sharing options...
loftmama Posted May 25, 2013 Share Posted May 25, 2013 Oh my, 3 days later, my head is spinning I've learned so much. So glad to find this. I'm pretty sure Evolution got about 5 minutes in all of my high school education. Thanks! (Although I still don't think I understand it all.) Quote Link to comment Share on other sites More sharing options...
Barb_ Posted September 21, 2013 Share Posted September 21, 2013 Quote Link to comment Share on other sites More sharing options...
Barb_ Posted September 21, 2013 Share Posted September 21, 2013 I'm not sure which rabbit trail caused me to ressurect this thread, but I think it's timely given the Texas textbook thread. I'm going to link it, I believe. Quote Link to comment Share on other sites More sharing options...
Stellalarella Posted September 21, 2013 Author Share Posted September 21, 2013 After this early 2012 discussion and tutoring session, I read The Beak of the Finch, Why Evolution Is True, The Violinist's Thumb, and Darwin's Black Box. I was glad to gain an understanding of evolution, though it has also raised many questions for me, esp. in theological areas. It's led me to teach my children differently (now choosing books, DVD material that support evolution) and I tell my kids as we've began studying the ancients again this year that we cannot ignore the fact that we have human-like fossil bones that speak to a much older history than I had previously accounted for. As a Christian, I have to give pause and think about the Biblical Adam and Eve. I don't have everything all sorted out yet. I read Darwin's Black Box third out of the four books I listed here. It also raised questions for me that I don't find satisfactorily answered by evolution. In short, I am glad I started down a path of understanding on this issue and I continue to learn and ponder as I go on. My kids benefit both from the new science training and also from watching me explore new subjects. Quote Link to comment Share on other sites More sharing options...
Cricket Posted September 21, 2013 Share Posted September 21, 2013 After this early 2012 discussion and tutoring session, I read The Beak of the Finch, Why Evolution Is True, The Violinist's Thumb, and Darwin's Black Box. I was glad to gain an understanding of evolution, though it has also raised many questions for me, esp. in theological areas. It's led me to teach my children differently (now choosing books, DVD material that support evolution) and I tell my kids as we've began studying the ancients again this year that we cannot ignore the fact that we have human-like fossil bones that speak to a much older history than I had previously accounted for. As a Christian, I have to give pause and think about the Biblical Adam and Eve. I don't have everything all sorted out yet. I read Darwin's Black Box third out of the four books I listed here. It also raised questions for me that I don't find satisfactorily answered by evolution. In short, I am glad I started down a path of understanding on this issue and I continue to learn and ponder as I go on. My kids benefit both from the new science training and also from watching me explore new subjects. I'm working my way through the book Redeeming Science by Poythress right now. Some of it deals with the creation/evolution debate but it is interesting to see his approach as a Christian and to see how much he loves science. Quote Link to comment Share on other sites More sharing options...
Stellalarella Posted September 22, 2013 Author Share Posted September 22, 2013 I'm working my way through the book Redeeming Science by Poythress right now. Some of it deals with the creation/evolution debate but it is interesting to see his approach as a Christian and to see how much he loves science. I will add it to my list--Thank you Cricket for sharing. Quote Link to comment Share on other sites More sharing options...
HomeschoolMamaOfTwo Posted September 23, 2013 Share Posted September 23, 2013 Loved this thread, thanks so much! Quote Link to comment Share on other sites More sharing options...
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