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Author Topic:   evolutionary chain
Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 64 of 204 (259703)
11-14-2005 5:12 PM
Reply to: Message 30 by mick
11-04-2005 9:10 PM


You have obviously already gotten a number of replies to this. I haven't read them yet. (I feel so behind in this whole thing). Anyway thank you for this chain. What I'm most curious about is the similarities and differences between Dalanistes and Rodhocetus. From the picture I can see that Dalanistes has legs and Rodhocetus does not. Also Dalanistes has a smallish neck and Rodhocetus doesn't. And maybe you could give me the evidence for why it is believed that Rodhocetus is decended from Dalanistes. There seem to be a few "missing links" here, right at the crucial point of transition from land to water.

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Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 65 of 204 (259708)
11-14-2005 5:24 PM
Reply to: Message 54 by mick
11-06-2005 8:55 PM


Ok, this one's a bit more clear and I can see that Rodhocetus DOES have something like legs. They still seem much different than Dalaniste's legs, especially the back legs.

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Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 136 of 204 (263978)
11-28-2005 11:59 PM
Reply to: Message 112 by RAZD
11-16-2005 7:37 AM


Re: Note to Christian
Thanks RAZD, this should be helpful. It's hard to sift through all this and figure out where I left off. Interesting reading though.

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Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 137 of 204 (263979)
11-29-2005 12:17 AM
Reply to: Message 115 by RAZD
11-16-2005 8:10 AM


Re: Pelycodus
The numbers down the left hand side indicate the depth (in feet) at which each group of fossils was found. As is usual in geology, the diagram gives the data for the deepest (oldest) fossils at the bottom, and the upper (youngest) fossils at the top. The diagram covers about five million years.
Are you sure the numbers down the left hand side indicate the depth at which each group of fossils were found? Because those numbers get smaller as you go down and if they indicate depth, I would think they would get larger. Am I missing something? Of course I'm not making any exciting point here, just trying to understand the chart.

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Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 138 of 204 (263980)
11-29-2005 12:25 AM
Reply to: Message 115 by RAZD
11-16-2005 8:10 AM


Re: Pelycodus
Still this seems like a transition from lemur to lemur. I would like to see pictures of these guys. Do they cross any distinctive lines?

This message is a reply to:
 Message 115 by RAZD, posted 11-16-2005 8:10 AM RAZD has replied

Replies to this message:
 Message 139 by RAZD, posted 11-29-2005 9:02 PM Christian has replied

  
Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 142 of 204 (264828)
12-01-2005 5:21 PM
Reply to: Message 139 by RAZD
11-29-2005 9:02 PM


Re: Pelycodus
From lemur-like to lemur-like. These predate lemurs, and they also diverge later into two genuses of species, so only one of them ends up possible related to lemurs:
ok so this is not what I was looking for. I would like to see something distinctive being developed. Looks like they got bigger,and then some got bigger while others got smaller. That's interesting, but not what I was looking for.
I took a look at the chipmunk thread, also interesting, but more talking about the idea that macroevolution CAN occur, by the same processes with which microevolution occurs. Still, I don't see a macroevolutionary chain.

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 Message 139 by RAZD, posted 11-29-2005 9:02 PM RAZD has replied

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 Message 143 by RAZD, posted 12-03-2005 10:11 PM Christian has replied

  
Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 144 of 204 (265825)
12-05-2005 5:12 PM
Reply to: Message 143 by RAZD
12-03-2005 10:11 PM


Re: Pelycodus
What you need to understand is that you will never see a massive change in a short time
I'm not looking for change in a short time. I don't care how long the chain is, I only want to see that one could've evolved from the previous up until we have something distinctively different. It doesn't even have to be from the fossil record. If evolution were correct, I would think there would be countless possible chains like this, living and fossilized. The big horse with one toe and the little horse with three toes are both horses. There are many different kinds of dogs and many different kinds of cats. I think it is possible that all cats evolved from a common cat ancestor. What I would like to know is what did the first cats evolve from that were not cats and how did the transition likely take place?
There is a "rule" that given the opportunity all species will tend to increase in size. It is a general rule rather than a hard and fast one, but it often pans out in practice.
Are we on a "downward trend" then? Because it is my understanding that there used to be giant dragonflies and beetles and lizzards, larger than any we know of today. This may be off topic though.
What I find intersting is that the size increase likely means that at some point the behavior of the species has to change (especially for an arboreal creature) as it is no longer able to take advantage of the original habitat of the smaller original species, and thus it is likely leaving a void for a smaller animal to take advantage of. The rapid (relatively speaking) reduction in size of the second species down to the original species size does two things then: it takes advantage of the void left by the increase in size and it differentiates the niche of the smaller one from the bigger one so that they are not in such direct competition as would otherwise be the case.
Same question as above, then. Why are there not larger creatures than what once existed, long ago?
This is the point at which these two species split, the moment of division between their lines, but it is also the point at which two genuses split: One goes on to become the genus Smilodectes and the other goes on to become the genus Notharctus. This is a division above the species level, as each genus includes several species that are more closely related to each other than they are to the other genus species:
They may be classified as different genuses, but what is so different about them? All I could tell from the chart is that they changed in size.
The two species later became even more distinct, and the descendants of nunienus are now labeled as genus Smilodectes instead of genus Notharctus.
Then maybe you can show me the chain of them becoming more distinct?
I guess I have to ask what you think macroevolution is and how it occurs?
I think macroevolution is where there is a change from one "kind" of animal to another. I don't know, though, how to define "kind" except that it includes animals which are distinct meaning they do not interbreed, or have some feature which is distinct from other animals. I do not think it occurs. The man-made classifications don't seem adequate for drawing lines, but wherever there is something distinct, it is unknown what the most recent ancestors were, as far as I can tell. I realize there are animals which do not interbreed, but likely have common ancestry. All I'm saying is that it is obvious to me that aminals which DO interbreed are an exception.
Some examples of what I would like to see the chain of development for: The amniotic egg of reptiles, the jumping aparatus of the click beetle, the pentadactyl limb of tetrapods, the spinneret and male copulating organ of spiders, the wing of a bat the water vascular and ambulacaral systems of echinoderms, the neck of the giraffe, the male reproductive organs of the dragonfly. Those examples were taken from Michael Denton's book "Evolution: a Theory in Crisis" But I could add the metamorphis of the butterfly or the shell of a turtle. Any of those would be very interesting to me.
Hope that's helpful. Actually, to be honest, I hope I've stumped you, since I don't want evolution to be true.

This message is a reply to:
 Message 143 by RAZD, posted 12-03-2005 10:11 PM RAZD has replied

Replies to this message:
 Message 145 by RAZD, posted 12-05-2005 8:39 PM Christian has replied

  
Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 146 of 204 (266916)
12-08-2005 4:46 PM
Reply to: Message 145 by RAZD
12-05-2005 8:39 PM


horse evolution
this is from the link you gave me about horse evolution:
Professor Marsh (who also named eohippus and Pliohippus) was not trying to confuse us when he named Miohippus in 1974. At the time, he believed that these fossils came from Miocene rocks. More recent work indicates that nearly all species of Miohippus, in fact, lived in the Oligocene. Though the name is somewhat misleading, we are stuck with it.
Why is it that he thought they were found in the Miocene rocks? Didn't the people who found the fossils tell him which layer of rocks they were found in? I suspect that this isn't as clear cut as it seems. That dating layers isn't as easy as you guys make it seem.

This message is a reply to:
 Message 145 by RAZD, posted 12-05-2005 8:39 PM RAZD has replied

Replies to this message:
 Message 147 by NosyNed, posted 12-08-2005 4:53 PM Christian has replied
 Message 150 by RAZD, posted 12-09-2005 5:52 PM Christian has not replied

  
Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 148 of 204 (266947)
12-08-2005 6:08 PM
Reply to: Message 145 by RAZD
12-05-2005 8:39 PM


Re: Pelycodus
Do you agree that one toe is distinctivly different from three toes? Or are we redefining what "distinctively" means? As I said we may need some further definition of the positions.
Actually, I think that #1 under distictive is a pretty good definition: 1. Serving to identify; distinguishing: distinctive tribal tattoos. See Usage Note at distinct. What I mean is a defining characteristic. Something like the trunk of the elephant, or the quills on a porcupine.
To me the difference between the horses is very distinctive, based not just on one having three (back) and four (front) toes and the other only one on each foot, but in the relative sizes, the changes in the teeth, the changes in the jaw, the changes in the legs, the changes in the torso, the changes in the tail ....
Perhaps, but I would think you could find something better. I gave you lots of possible options, can you not find chains for any of those?

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 Message 145 by RAZD, posted 12-05-2005 8:39 PM RAZD has replied

Replies to this message:
 Message 149 by RAZD, posted 12-08-2005 11:25 PM Christian has replied

  
Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 151 of 204 (268327)
12-12-2005 5:04 PM
Reply to: Message 147 by NosyNed
12-08-2005 4:53 PM


Re: Maintaining focus
OH yeah, I was slipping off topic again. Sorry.

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 Message 147 by NosyNed, posted 12-08-2005 4:53 PM NosyNed has not replied

  
Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 152 of 204 (268381)
12-12-2005 6:45 PM
Reply to: Message 149 by RAZD
12-08-2005 11:25 PM


Re: Pelycodus ...Horse ...Elephant?
Ok, if you can show me a gradual progression from a padded foot to a hoved foot, that will be good, since the horse is a pretty good runner on the feet he has, it's unlikely that this would just be a loss of something. Apparently that's what you've given me so I will have to research horse evolution and see how much validity there is. I'll let you know what I come up with.

This message is a reply to:
 Message 149 by RAZD, posted 12-08-2005 11:25 PM RAZD has replied

Replies to this message:
 Message 153 by RAZD, posted 12-12-2005 9:14 PM Christian has replied

  
Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 154 of 204 (269327)
12-14-2005 5:29 PM
Reply to: Message 153 by RAZD
12-12-2005 9:14 PM


Re: Pelycodus ...Horse ...Elephant?
Actually that horse chart you gave me doesn't give a description of the foot at each stage. I would really like to see that. Do you think you could find something like that for me?

This message is a reply to:
 Message 153 by RAZD, posted 12-12-2005 9:14 PM RAZD has replied

Replies to this message:
 Message 155 by arachnophilia, posted 12-14-2005 5:51 PM Christian has not replied
 Message 166 by RAZD, posted 12-14-2005 10:27 PM Christian has not replied

  
Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 169 of 204 (271511)
12-21-2005 5:01 PM
Reply to: Message 161 by arachnophilia
12-14-2005 8:17 PM


Re: hoof arted.
feel free to look up the species named in something that's not a webpage.
that's a good idea. I'll look them up in the vertebrate palentology book you recommended I read.

This message is a reply to:
 Message 161 by arachnophilia, posted 12-14-2005 8:17 PM arachnophilia has replied

Replies to this message:
 Message 170 by arachnophilia, posted 12-21-2005 5:12 PM Christian has replied

  
Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 171 of 204 (271520)
12-21-2005 5:27 PM
Reply to: Message 167 by arachnophilia
12-14-2005 11:10 PM


Re: Pelycodus ...Horse ...Elephant?
actually, there might be one in that book i recommended christian.
That's what I was thinking. (posted before I read this)
christian, do you still have that book from the library? if so, does it go into any detail about horse evolution?
I still have the book. I didn't have to check it out of the library since my husband already had a copy. It has some stuff about horse evolution. I need to look at it again. Been kind of out of it lately with being sick and then getting ready for Christmas.
I'm looking at it now, it has that same picture that you posted, or something very similar, with the horses hooves.
I'm just reading it a bit as I'm working on this post. Here's an interesting quote:
Early work suggested that horses constituted a single assemblage that progressed relatively steadily from the small sized Hyracotherium (Eohippus), with low-crowned teeth and four toes on the front feet and three on the rear, to the modern genus Equus, which has high-crowned teeth and whose manus and pes are reduced to a single toe. Subsequent research has demonstrated a much more complex radiation, with many divergent lineages of browsers and grazers overlapping one another in time.
Don't know whether that contradicts your idea of things or not, RAZD, but thought it was interesting. Anyway, I'll read this section thouroughly (doesn't look very long, so might not have any more explicit information that what I already have, but a good place to start). Then I'll let you guys know what I think.
Have a nice day and Merry Christmas.

This message is a reply to:
 Message 167 by arachnophilia, posted 12-14-2005 11:10 PM arachnophilia has replied

Replies to this message:
 Message 173 by arachnophilia, posted 12-21-2005 9:42 PM Christian has not replied
 Message 175 by RAZD, posted 12-23-2005 9:49 PM Christian has not replied

  
Christian
Member (Idle past 6281 days)
Posts: 157
Joined: 10-16-2005


Message 172 of 204 (271522)
12-21-2005 5:31 PM
Reply to: Message 170 by arachnophilia
12-21-2005 5:12 PM


Re: hoof arted.
i don't recall if it goes into horse evolution in specific, though i'm sure you could find whole books on that. i used the part on bird evolution for a art project, thought it was one of many resources, and not my primary one. it's far too general, really
Yeah, it seems pretty general. I looked on amazon for some books specifically on horse evolution and didn't come up with much. What they had was pretty expensive. Maybe I'll check the library.

This message is a reply to:
 Message 170 by arachnophilia, posted 12-21-2005 5:12 PM arachnophilia has replied

Replies to this message:
 Message 174 by arachnophilia, posted 12-21-2005 9:43 PM Christian has not replied

  
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