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Author | Topic: Transitional forms in existence today | ||||||||||||||||||||||||||||||||||
Percy Member Posts: 20733 From: New Hampshire Joined: Member Rating: 2.2 |
My God, sometimes the creationist ability to confound things borders on genius. Do you care to tell us who actually used the phrase "the maintenance of stability within species" (it wasn't Dawkins), and as a bonus question, give us the full context so we can see what was actually meant? And what was the source and context of the Richard Dawkins' quote? All species are transitional. Both Gould and Dawkins are aware of that and would have no reason to contradict what they believe to be true. --Percy
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Dr Jack Member (Idle past 1333 days) Posts: 3507 From: Leicester, England Joined: |
It's kinda true that many species are transitional - obviously not all, because any species that goes extinct is not - but it's a broader meaning of the word 'transitional' than the one being discussed. In general usage, when we talk about transitionals without context what we're talking are transitionals specifically between distinct higher taxonomic groups.
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Larni Member Posts: 4000 From: Liverpool Joined: |
Think you might need to check your source, for that one.
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Larni Member Posts: 4000 From: Liverpool Joined: |
Please tell me this is clever use of Poe's Law.
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Bojan Junior Member (Idle past 2534 days) Posts: 9 From: Croatia, Europe Joined: |
There are many transitional forms today. When we say transitional, I guess it means a spiecies wich gradualy changes it's way of life, usualy because of enviromental changes, predators, or something like that.
1) Polar bear http://en.wikipedia.org/wiki/Polar_bear 2) Seal http://en.wikipedia.org/wiki/Sea_Leopard 3) Penguin http://en.wikipedia.org/wiki/Penguin 4) Manatee http://en.wikipedia.org/wiki/Manatee So, above are example of modern land to water transitions. Whale and dolphin ancestors probably had a similar way of life some time in past. 5) Flying squirrel http://en.wikipedia.org/wiki/Flying_squirrel 6) Walking fish http://en.wikipedia.org/wiki/Walking_fish All above animals are nice examples because they're going through changes which already occured in past to other spieces, so we can clearly correlate and recognize various stages. These are just examples from top of my head, if I think of something else, I'll post more.
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Modulous Member (Idle past 1332 days) Posts: 7789 From: Manchester, UK Joined: |
Source - NOW with Bill Moyers. Transcript. December 3, 2004 Context: quote:
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pandion Member (Idle past 2229 days) Posts: 166 From: Houston Joined: |
quote: I checked and found that all species of otter are indeed, semi-aquatic. So what was your point?
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Taq Member Posts: 8519 Joined: Member Rating: 3.3 |
Evolution also involves natural selection. It is a two step process where random mutation produces variation within the population and natural selection reduces the number of deleterious mutations while increasing the number of beneficial mutations.
Your question can take on many meanings, so you may need to clarify exactly what you are looking for. Do you mean to ask why we don't see transitional features that carried over from past evolutionary events? If so, then your question is easily answered. Let's use mammals and reptiles as an example. From the fossil record we know that modern mammals evolved from ancient reptiles. This means that modern reptiles and modern mammals share a common ancestor. Both lineages branched off at this point, and each lineage continued to evolve. In the mammal lineage, many of the branches died off. However, there is one mammalian lineage where these transitional features have been preserved: the monotremes. The most famous species of monotreme is the platypus. In this species we see a very primitive lactation system, a body temperature much cooler than other mammals, and leathery eggs like those laid by modern reptiles. As you can imagine, not all transitional features are going to be preserved in a lineage over time. There are two things to keep in mind: 1. All lineages evolve. Reptiles did not stop evolving after mammals branched off. The same goes for all of the mammalian lineages that branched off after they evolved from reptiles. 2. Extinction happens. Lineages where transitional features can still be seen are at risk for extinction, as much as any other lineage. One of the reasons we do not see preserved transitional features is that those lineages went extinct.
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peter1985 Junior Member (Idle past 3791 days) Posts: 4 Joined: |
Very interesting. Thanks for the replies.
Before I started my research towards a conviction of the topic I decided the wisest way to do it was to approach it with an open mind and as little a bias as possible . Consequently, I read a lot of intelligent design/creationist literature, much of which I have learned over the past year is scientifically inaccurate or misconstrued science. I remember one such book had a chapter devoted to the alleged lack of transnational forms as evidence for a creator and charged that if random mutation was the mechanism for evolution there would be more species "in flux" than wholly formed species. I now see the fallacy that the subjectivity in that argument creates.
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New Cat's Eye Inactive Member |
Well, there's your problem...
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Taq Member Posts: 8519 Joined: Member Rating: 3.3
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peter1985,
Languages are a good analogy to use when trying to understand how evolution works. As you may know, the Romance Languages are a language group that "evolved" from Latin. Here is an idealized lineage for the Romance languages: So you may ask why don't we hear anyone speaking a transitional language. If you went back 1,000 years you would be asking the same question even though those languages 1,000 years ago were the transitional langages between modern languages and vulgar latin. Also, the descendants of those who spoke proto-Italian, for example, are not speaking modern Italian. If humans evolved from a common ancestor with other apes why don't we see any transitional hominids today? For the same reason that no one speaks Middle English today. Edited by Taq, : No reason given.
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Larni Member Posts: 4000 From: Liverpool Joined:
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Seems I mis read your post. I thought when you said 'all species' you were referring to all species of mustelids, rather than all species of otter.
I do beg your pardon.
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ZenMonkey Member (Idle past 3739 days) Posts: 428 From: Portland, OR USA Joined: |
Shucks Chuck, have you not been paying attention to the content of the scientifically literate posts in any of the topics you've been participating in? That's not at all what transitional means, and you'd know that if you'd read any other of the replies in just this topic here. I don't mean to sound critical, but you've actually been better than most at taking an honest look at the evidence you've been exposed to here, and I had hoped that you were having your eyes open to the faults in what you'd be told in the past by the scientifically illiterate. What happened? I also note that you've taken a very defensive tone in your debate with Straggler. Is any of that bleeding over into your post here, even though the topics are quite different? I've been reading The Dawkins Delusion? as you suggested, but it's taking some time because I have to keep stopping to re-read the relevant passages in The God Delusion. Hard to believe that McGrath's understanding of Dawkins's book is so far apart from what it actually says. In the meantime, I hope that you've been reading some of the books on the facts of evolution that I listed for you. They would make topics like this much clearer for you. Your beliefs do not effect reality and evidently reality does not effect your beliefs. -Theodoric Reality has a well-known liberal bias. I never meant to say that the Conservatives are generally stupid. I meant to say that stupid people are generally Conservative. I believe that is so obviously and universally admitted a principle that I hardly think any gentleman will deny it.
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Taq Member Posts: 8519 Joined: Member Rating: 3.3 |
What transitional mammalian features do penguins have?
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Dr Adequate Member (Idle past 280 days) Posts: 16112 Joined: |
To be precise, it's a false dichotomy. An Archaeopteryx was an intermediate form but it was also a "wholly formed" Archaeopteryx.
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