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Author | Topic: Quick Questions, Short Answers - No Debate | |||||||||||||||||||||||||||||
kuresu Member (Idle past 2534 days) Posts: 2544 From: boulder, colorado Joined: |
I'll see if I can dig up the soil types around here. Unfortunately I no longer have my grandfather to ask, as he was a geologist/civil engineer with a Swedish firm (not sure if he actually worked for the swedish gov't, though). On the plus side, Uppsala is known for its sciences, so I'm sure there's someone/thing with relevant info.
Thanks.
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BMG Member (Idle past 230 days) Posts: 357 From: Southwestern U.S. Joined: |
Interior Secretary Ken Salazar announced that the Obama administration will leave in place an unpopular Bush rule on the protection of polar bears. The decision comes despite an outcry from Democrats, environmental activists and scientists alike, who promised to push to overturn the rule in court. Obama Leaves Polar Bears Out in the Cold The Polar Bear seems doomed, regardless of our efforts, but must we kick it while it's down? Or nonchalantly step over it while it lies helpless under our feet? Am I overreacting? Edited by Admin, : Reduce length of long link.
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Modulous Member Posts: 7801 From: Manchester, UK Joined: |
From Message 256:
...and the tendency is to refer to {ancient near eastern works} by the first significant noun or action in the work.
But not when translated? Or is this just a quirk of English translations?
I don't know the history of putting titles to works, but I feel confident that some 'blame' belongs to the Greeks. So, for the moment, let's call it a quirk of the Greeks that the Romans and subsequently the rest of the world inherited. One assumes that the Greeks used their own convention because either they were unaware of the near eastern one - or perhaps more likely, they preferred their own convention. "And He called" doesn't tell a person what the book is about, which seems to be what the Greeks aimed for in their titles. Edited by Modulous, : No reason given.
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BMG Member (Idle past 230 days) Posts: 357 From: Southwestern U.S. Joined: |
I have recently finished an intro to Bio course, and the class text, Biology: Concepts And Connections: Sixth Edition (sorry, don't feel like looking up the correct form for citing sources) claims that, on page 398, that,
quote: On the previous page, 397, it reads
quote:. However, wikipedia quotes Colin Tudge below;
quote: Bold mine. A few weeks ago, speaking to some friends, I mentioned that birds were actually feathered reptiles. Was I accurate in repeating my text's claim? I would really appreciate any feedback. Thank you.
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Dr Adequate Member (Idle past 306 days) Posts: 16113 Joined: |
I guess if you define reptiles as aminotes which aren't birds or mammals, then you can't say that birds are reptiles. Dinosaurs, yes ... but wait, aren't dinosaurs reptiles? Well, according to that definition, only the ones that aren't birds.
So what's Caudipteryx ... ? Edited by Dr Adequate, : No reason given.
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Coragyps Member (Idle past 756 days) Posts: 5553 From: Snyder, Texas, USA Joined: |
The term "reptiles" includes "lizards, snakes, turtles, crocodiles, and birds,..." but it is a more-or-less obsolete term. Turtles are anapsids, and may not belong with those others, which are all diapsids. And we synapsids are descended from "mammal-like reptiles," which isn't very helpful in deciding if mammals are still reptiles or not.
A situation in flux, from my understanding. Birds are closer kin to crocodiles than to lizards, if that helps at all.
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Percy Member Posts: 22480 From: New Hampshire Joined: Member Rating: 4.8 |
Unlike Dr. Adequate and Coragyps, I am largely ignorant of the issues and problems of biological classification, and so I can give an answer with almost complete confidence.
Birds are not reptiles. Birds are dinosaurs, which are descended from reptiles. Mammals are not reptiles. Mammals share a common ancestor with reptiles. Reptiles are not amphibians. Reptiles share a common ancestor with amphibians. If my uninformed answer is sufficiently controversial then someone should propose a new thread. --Percy
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caffeine Member (Idle past 1046 days) Posts: 1800 From: Prague, Czech Republic Joined: |
It's just a matter of definition. Reptile in the traditional usage would not include birds, but if you wanted to define it as a monophyletic clade it would have to. Which to use is just personal preference.
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BMG Member (Idle past 230 days) Posts: 357 From: Southwestern U.S. Joined: |
Thanks for the replies, everyone.
So what's Caudipteryx ... ? Hmmm, currently, according to wiki,
quote: It gets better. A little futher down, from the same source,
quote: Bold mine. So birds evolved from theropods, which were small, two-legged dinosaurs; well, most were small, I suppose, for, again, wiki claims that theropods
quote: Thanks, DA.
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Blue Jay Member (Idle past 2719 days) Posts: 2843 From: You couldn't pronounce it with your mouthparts Joined: |
Hi, BMG.
Forgive me for drawing this out, but I felt I had some additional insight to help answer the question. The classification of organisms used to be categorical, such that animals could be placed into different groups based on whether or not they had a requisite array of defining characteristics. The system works just fine if your intent is just to group things by appearance. However, there is always the question of why you would want to group them that way. But, modern biology uses evolution as the guide for classifying animals, such that true ancestry and relatedness are more important than morphological features. So, modern taxonomists will group everything that evolves from a reptile as a reptile, and will only distinguish two reptiles from one another by means of subgroups placed within the group "reptiles." Thus, birds would appropriately be considered a subgroup of reptiles, for instance. This system works well because evolution is considered central to modern biology, and it provides a clearer picture of the history of life, so we are better able to see what factors shape the processes of life. Furthermore, it gives us some predictive ability: we can anticipate some of the ecological traits of some species based on what we know about closely related species, because closely related species are often affected similarly by similar environmental factors. The problems come in when you start mixing terms from the categorical system with terms from the cladistic system. The word "reptile" is essentially meaningless in terms of evolution-based classification, because it groups things in terms of something other than evolutionary ancestry, and you'll only confuse people by trying to use both classification systems at once. So, before even bothering to use a term such as "reptile," it's important to understand why you want to use it and what the term is going to convey to the person you're using it for. -Bluejay (a.k.a. Mantis, Thylacosmilus) Darwin loves you.
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BMG Member (Idle past 230 days) Posts: 357 From: Southwestern U.S. Joined: |
The term "reptiles" includes "lizards, snakes, turtles, crocodiles, and birds,..." but it is a more-or-less obsolete term. Turtles are anapsids, and may not belong with those others, which are all diapsids. And we synapsids are descended from "mammal-like reptiles," which isn't very helpful in deciding if mammals are still reptiles or not. In essence, it sounds as if I should simply stay away from the term "reptile" all together. Anapsids have skulls that lack openings near the temples. Diapsids have two openings on their skulls, one on each side("di"). Again, from wiki, about synapsids
quote: And synapsids have a single hole behind each eye orbit.
A situation in flux, from my understanding. Birds are closer kin to crocodiles than to lizards, if that helps at all. Yes, it does. I guess I may have had it right when I started this post; I think I will stay away from the term reptile altogther. Thanks, Coragyps.
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BMG Member (Idle past 230 days) Posts: 357 From: Southwestern U.S. Joined: |
Thanks Percy, Caffeine, and Bluejay for the replies.
I'm less knowledgable than all three of you, I'm sure, in biology, so let's see if I have this straight. The term "reptile" was borne from the outdated, morphological system of classification, and the new form of classification, based on evolution, determines, as Bluejay has put it, "true ancestry and relatedness". A work in taxonomic progress, I suppose. Birds belong to the Aves clade, mammals to the mammalia clade, and both are subgroups within the larger clade, Amniota. So, are most or all of the animals formerly known as reptiles undergoing a taxonomic classification upgrade, and being allocated to their respective clades? A wait-and see-approach for those interested in the subject?
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roxrkool Member (Idle past 1010 days) Posts: 1497 From: Nevada Joined: |
Great post! That was very informative.
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Dr Adequate Member (Idle past 306 days) Posts: 16113 Joined: |
I presume that if you took bacteria which could synthesize some chemical necessary to their metabolism, and you grew them in a culture rich in this chemical, they would eventually stop making it for themselves.
Does anyone know of such an experiment?
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Itinerant Lurker Member (Idle past 2677 days) Posts: 67 Joined: |
How are genetic markers dated? What I mean is, when genetic markers are used to track population movements throughout human history like this one,
National Geographic - 404 How are the dates associated with the various populations arrived at?
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