Major transitions in evolution

[painted wolf]

I love fishapods!
These wonderful critters are so perfectly blurring the line between fish and tetrapods that it's all but impossible to point to where one group ends and the other begins.

The most traditionally fish-like: Panderichthys and Tiktaalik show wonderfully tetrapod like features of the skull, limbs and vertebra... while the most tetrapod-like: Acanthostega and Ichthyostega still have wonderfully fish like features such as gills, extra digits and fishy scales.

They show how the major features off tetrapods developed over millions of years such as the positions and shapes of major skull bones.

Shape and position of the major limb bones

Modern genetics even helps us understand how altering the timing of activation in developmental genes led to these changes in limb development.

Even being able to trace specific mutations that produce many of these changes between us.
* this is a really huge image so I'm just giving a link.
http://www.biomedcentral.com/content/figures/1471-2164-7-83-7-l.jpg

Just a very brief glimpse into the transition from water to land.

wa:do

 

[painted wolf]

Here is another group I adore... Synapsids.
The oldest members of the group look essentially like lizards, but have key features especially in the skull, that show they are something quite different. (but that is like us)
The youngest members of the group are so close to being mammals that they even have evidence of having had hair like us.
Like the fishapods there is a very fuzzy line that separates us from them.
Some of the key developments in Synapsids was the movement of jaw bones that eventually become the mammal inner ear... changes in the teeth that go from simple lizard like teeth to the varied multi-use teeth of mammals and increasing complexity of the brain.

some illustrations showing some examples from this transition:

some overall changes in the skeleton

there is an excellent book for those interested in more about this particular group:

Amazon.com: The Origin and Evolution of Mammals (Oxford Biology) (9780198507611): T. S. Kemp:…

wa:do

 

[Commoner]

These are very imaginative drawings, but there is no evidence for macroevolution. The Bible is the only true source of knowledge.

No, seriously, nice post. Frubals!

 

[xkatz]

Those paleontologist still need to find those damn unicorn fossils...

<3

 

[Commoner]

Those paleontologist still need to find those damn unicorn fossils...

<3

Bah, unicorns don't leave behind bodies, they turn into stardust!

Some people...

 

[painted wolf]

Here is a video demonstrating one of my favorite genetic evidences of evolution... ERV's (endogenous retroviruses) and pseudogenes.

[youtube]8ZvTmgCk1Lo[/youtube]
YouTube - Facts Of Evolution: Retroviruses And Pseudogenes!

wa:do

 

[RedOne77]

Nice video, although they forgot to mention that ERVs can be inserted by some insects like mosquitoes that can transmit blood from one organism to another (creation 1, eviluitonism 0). And that changes to the ERV sequence itself can be used to further map out family trees, same with pseuodgenes.

 

[fantome profane]

Nice video, although they forgot to mention that ERVs can be inserted by some insects like mosquitoes that can transmit blood from one organism to another (creation 1, eviluitonism 0).

Did you forget to wink this time? Or are you serious?

 

[RedOne77]

I'm serious that mosquitoes can cause ERVs (or so I've heard), the parentheses part was added for fun.

 

[fantome profane]

I'm serious that mosquitoes can cause ERVs (or so I've heard), the parentheses part was added for fun.

Yes I have heard this as well, but to suggest that they can infect the same part of the same chromosome of multiple species, that just happen to seem to be closely related is ridiculously absurd. And of course they would need to infect not just any cell, but the reproductive cells. And they would have to do this multiple times. And even if this could be caused by multiple infections we would see a random pattern, or perhaps a pattern based on geographic proximity. For example we would see EVR’s shared by humans, and pigs, and chickens that are not shared by Gorillas or chimps. But this is not what we see. To account for the pattern we do see it would be as if these mosquitoes deliberately decided to infect specific species with specific retroviruses in order to make it look like common ancestry. (this could perhaps be the devil’s doing?)

I strongly recommend you reconsider the wink. Or as I suggested before one of these smilies.:bonk::jester5::jester3: (or perhaps all of them)

 

[fantome profane]

Here is another excellent video on ERV’s, this one by cdk007[FONT=&quot]
[/FONT][youtube]TUxLR9hdorI[/youtube]
YouTube - Evidence for Evolution, Part III



This video explores the odds against what RedOne77 suggests. The only reasonable conclusion of ERV’s is that we share a common ancestor with other primates. I repeat - the only reasonable conclusion!

 

[Commoner]

This video explores the odds against what RedOne77 suggests. The only reasonable conclusion of ERV’s is that we share a common ancestor with other primates. I repeat - the only reasonable conclusion!

Yeah, unfortunately, it's not the only conclusion. Not everyone values reason...

 

[Super Saiya Jinn]

Yes I have heard this as well, but to suggest that they can infect the same part of the same chromosome of multiple species, that just happen to seem to be closely related is ridiculously absurd. And of course they would need to infect not just any cell, but the reproductive cells. And they would have to do this multiple times. And even if this could be caused by multiple infections we would see a random pattern, or perhaps a pattern based on geographic proximity. For example we would see EVR&#8217;s shared by humans, and pigs, and chickens that are not shared by Gorillas or chimps. But this is not what we see. To account for the pattern we do see it would be as if these mosquitoes deliberately decided to infect specific species with specific retroviruses in order to make it look like common ancestry. (this could perhaps be the devil&#8217;s doing?)

:bow:

Frubals.

 

[painted wolf]

RedOne- Yes mosquitoes are a viral vector... however, retroviruses tend to be species specific. Thus a human retrovirus will not infect a Gorilla or a mouse or a cow... the only way for all species to share an ERV like this is to have had a common ancestor who caught a species specific retrovirus.
When you add that the retrovirus needs to infect a somatic cell that becomes successful in fertilization and for creationism to be supported, this has to insert repeatedly into specific loci on the chromosome... and then mutate in the same way across various lineages in a way that resembles common decent. Frankly the creationist view on ERV's becomes tenuous at best.

I know you aren't big on non-textbook reading on science... but I highly recommend the blog ERV to learn more about the current research on these fascinating bits of evolutionary heritage. It is written by a graduate student who is actively reseraching ERV's as well as the evolution of HIV... so she knows her viruses. (her blog is where I found the vid actually.)

here are her ERV specific posts:
ERVs : erv

wa:do

 

[RedOne77]

RedOne- Yes mosquitoes are a viral vector... however, retroviruses tend to be species specific. Thus a human retrovirus will not infect a Gorilla or a mouse or a cow... the only way for all species to share an ERV like this is to have had a common ancestor who caught a species specific retrovirus.
When you add that the retrovirus needs to infect a somatic cell that becomes successful in fertilization and for creationism to be supported, this has to insert repeatedly into specific loci on the chromosome... and then mutate in the same way across various lineages in a way that resembles common decent. Frankly the creationist view on ERV's becomes tenuous at best.

Indeed, I just thought I'd throw out the creation answer to ERVs. Advocatus Diaboli.

I know you aren't big on non-textbook reading on science...

It's not that I'm against such reading, I just prefer to spend the time with friends doing other things.

but I highly recommend the blog ERV to learn more about the current research on these fascinating bits of evolutionary heritage. It is written by a graduate student who is actively reseraching ERV's as well as the evolution of HIV... so she knows her viruses. (her blog is where I found the vid actually.)

here are her ERV specific posts:
ERVs : erv

wa:do

Nice site, I browsed around a little; it's been bookmarked and I'll try to stop in every now and then.

 

[fantome profane]

Indeed, I just thought I'd throw out the creation answer to ERVs. Advocatus Diaboli.

Maybe you should wink even when you are just “playing devil’s advocate” :devil:. You should perhaps wink every time you make an argument you are not prepared to stand behind.

But I agree that the creation answer is something that should be thrown out.

 

[RedOne77]

Maybe you should wink even when you are just “playing devil’s advocate”. You should perhaps wink every time you make an argument you are not prepared to stand behind.

Maybe I should just put ":devilevil's Advocate:devil:" at the end of my signature. After all, I'd say ruffly 90% of my posts were me playing devil's advocate . Shrewd, yes, but after 2-3 years of being an evo on these types of sites I'd thought I'd switch things up a bit and defend creationism for once. In my defense I tried to leave clues behind, and some quite early; remember this thread? http://www.religiousforums.com/forum/evolution-vs-creationism/93821-i-thought-interesting-find.html

Anyway, I am getting tired of constantly defending something that I don't agree with, and some may have noticed me gravitating to an evolutionist mind set recently (just look at my conversations with Jollybear). So I'll make this my official statement of 'switching sides' to the evilutionist-ism camp. :yes:

But I agree that the creation answer is something that should be thrown out.

My favorite one thus far has been that during the flood certain species have survived on floating islands. On the surface you can make a pretty interesting case, nullifying the extreme hyper-evolution needed to repopulate the world, and I attempted to do just that when I first joined.

I hope no one is too ticked off about the whole thing :sorry1:

Since I am somewhat like a new person, I'll just reaffirm that I am a Christian and an evolutionist. And I'll be sure to make it obvious when I am playing :devilevil's Advocate:devil: from now on.

 

[David M]

My favorite one thus far has been that during the flood certain species have survived on floating islands. On the surface you can make a pretty interesting case, nullifying the extreme hyper-evolution needed to repopulate the world, and I attempted to do just that when I first joined.

Trouble with that one is that it makes god a liar or it proves the bible is not inerrant or it shows that the Noah story was not meant to be taken literally.

Genesis 7 (KJV)
21 And all flesh died that moved upon the earth, both of fowl, and of cattle, and of beast, and of every creeping thing that creepeth upon the earth, and every man:
22 All in whose nostrils was the breath of life, of all that was in the dry land, died.
23 And every living substance was destroyed which was upon the face of the ground, both man, and cattle, and the creeping things, and the fowl of the heaven; and they were destroyed from the earth: and Noah only remained alive, and they that were with him in the ark.

If the bible is true and literal no animal could have lived on those "floating islands".

 

[Noaidi]

Since I am somewhat like a new person, I'll just reaffirm that I am a Christian and an evolutionist. quote]

That's okay. :yes: The zoology professor that taught me evolution at university often used to come in with a dog collar on - not for effect, but becuase he was also an Anglican minister who had to leave quickly after the lecture to conduct a marriage or some such service.

There should be no incompatibility between being a believer in god and accepting evolution.

 

[painted wolf]

A significant portion of my biology professors... (more than 50% of those who's religious affiliation I know) are Christians.

wa:do