Freethought & Rationalism Archive

MrDarwin · 06-20-2002, 05:11 AM

Quote:

Originally posted by lpetrich:
I was searching for some discussion of the evolution of the frog's tadpole phase when I came across <a href="http://www.users.bigpond.com/rdoolan/amphrep.html" target="_blank">this creationist page</a>, which flatly denied that amphibians can evolve into reptiles.

As usual, creationists erect the straw man of modern reptiles evolving from modern amphibians. Modern amphibians are highly specialized and quite a bit different from the earliest amphibians (in fact I would suggest that these early creatures, from which both reptiles and modern amphibians evolved, should not themselves be called amphibians). The earliest tetrapods (land-dwelling vertebrates with 4 legs) were actually quite fish-like.

Regarding the metamorphosis of amphibians from aquatic larvae, I suspect this may actually be a primitive characteristic of amphibians, retained from their early fish-like ancestors. However, this is not an insurmountable barrier. There are several modern amphibians that lay eggs on land, including some <a href="http://www.fcps.k12.va.us/StratfordLandingES/Moran%20Website/mpages/red-backed_salamander.htm" target="_blank">salamanders</a> that lay clutches of eggs under rotting logs, etc. where they stay moist and hatch into miniature (i.e., not larval) salamanders.

[ June 20, 2002: Message edited by: MrDarwin ]

Blinn · 06-20-2002, 06:00 AM

Quote:

Originally posted by lpetrich:

What I had been looking for was some discussion of the question of whether early amphibians had also had an aquatic tadpole-like phase, and whether frogs' tadpole phase is a vestige of that. But I couldn't find anything, even though I suspect that both are correct.

I have <a href="http://www.amazon.com/exec/obidos/tg/stores/detail/-/books/0226557634/glance/ref=lib_rd_TFCV/104-9951678-8131127" target="_blank">Tadpoles: The Biology of Anuran Larvae</a> in my office, but I'm not there today, so I can't check it to see what it may have to say on the subject. I'll look tomorrow.

Quote:

Originally posted by scigirl:
About the specific tadpole question:

<a href="http://www.science.duq.edu/biology/faculty/elinson.html" target="_blank">http://www.science.duq.edu/biology/faculty/elinson.html</a>

This lab is trying to answer that very question:

Here's an online article by that lab: <a href="http://www.npb.ucdavis.edu/winter2002/128/recommended_readings_set2/Elinson_direct_dev_review.pdf" target="_blank">Frogs without polliwogs: evolution of anuran direct development</a>

Quote:

Originally posted by Morpho:


We used the red-eyed tree frog as a keystone species in one of our contracts: the elimination of riparian vegetation (by cattle) destroyed their nesting spots and caused the local population to go extinct over the space of only a couple years. We were able to show how the cattle knocked/trampled down the overhanging vegetation (where the female attaches her eggs) in their quest for water. We correlated this with the multiple-times increase in cattle in the area: which gave us additional impetus to have the area declared a wildlife preserve.

Morpho, were you working in Panama? I do some frog work there occasionally. In fact, I'm headed back next month.

Quote:

Originally posted by Morpho:

2. They don't sit on top of leaves - they're mostly hidden underneath - that's why they're usually really hard to spot, in spite of their coloration.

While this is generally true for most dendrobatid species, there are some that will go several meters up into vegetation to perch, such as Epipedobates tricolor.

[ June 20, 2002: Message edited by: Zetek ]

MOJO-JOJO · 06-20-2002, 06:20 AM

Quote:

Originally posted by ishalon:
<a href="http://www.secularhumanism.org/library/fi/dawkins_21_4.html" target="_blank">Article.</a>

How many creationists are like that? Firm unchanging-in-the-face-of-anything beliefs that have no ground at all?

This pretty much represents the thinking of just about every fundaMENTAList and evangelist that I have met or listened to in the past 5 years (including pretty much everyone at the church my family attends).

They trust completely in the Bible through faith, and do not care what "evidence" there is to undermine the "truth" of the bible. It is all man-made wisdom and a trick of the devil to them

.

My response;

"Faith is often the boast of the man who is too lazy to investigate."
~~F.M. Knowles

(But the problem here is that Kurt Wise is actually investigating, but is refusing to correctly interpret--with reason--what he "sees")

[ June 20, 2002: Message edited by: MOJO-JOJO ]

Quetzal · 06-20-2002, 07:05 AM

Quote:

Originally posted by Zetek:
Morpho, were you working in Panama? I do some frog work there occasionally. In fact, I'm headed back next month.

Nicaragua. The referenced contract was in Cerro Kum (north-central), near the edge of the Bosawas Biosphere Reserve between the Rio Bocay and Rio Coco (lowland Atlantic rainforest).

Quote:

While this is generally true for most dendrobatid species, there are some that will go several meters up into vegetation to perch, such as Epipedobates tricolor.

Leave it to a flippin' herpetologist to get in the last word.

I feel justified 'cause the only two species I'm familiar with are D. auratus and, IIRC, D. lehmanni (from the Rio San Juan/Indio-Mais Biological Preserve in southern Nicaragua - again lowland Atlantic rainforest). I didn't study the critters - they're just two of my favorite frogs... (I also have favorite snakes, favorite birds, favorite bees, favorite Felidae etc.)

Our best work was in the north near Matagalpa, in the Arenal Nature Preserve (not the one in Costa Rica but same name) and in the southwest in the La Flor Wildlife Refuge: all conservation biology and/or ecotourism management planning stuff. The Cerro Kum deal was an environmental impact assessment on a mining concession.

My turn - on what/where are you working in Panama?

[/QUOTE]

MOJO-JOJO · 06-20-2002, 07:16 AM

Morpho...more importantly....did you do any 'Snook' fishing while you were there?

Blinn · 06-20-2002, 07:17 AM

Quote:

Originally posted by Morpho:
My turn - on what/where are you working in Panama?

Proyecto Rana Dorada(Project Golden Frog)

Checkout our website (still under construction)

<a href="http://www.ranadorada.org" target="_blank">ranadorada.org</a>

Coragyps · 06-20-2002, 07:54 AM

Wow, Zetek! Those little guys are beautiful! And they share a species name with you?.....

I was crazy about the reptile house at the Columbus Zoo when I was living there - my wife wouldn't even go in the door. Snakeophobia?

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06-20-2002, 07:16 AM	#15
MOJO-JOJO Senior Member Join Date: Apr 2001 Location: Nashville, USA Posts: 949	Morpho...more importantly....did you do any 'Snook' fishing while you were there?

06-20-2002, 07:54 AM	#17
Coragyps Veteran Join Date: Aug 2001 Location: Snyder,Texas,USA Posts: 4,411	Wow, Zetek! Those little guys are beautiful! And they share a species name with you?..... I was crazy about the reptile house at the Columbus Zoo when I was living there - my wife wouldn't even go in the door. Snakeophobia?

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