Freethought & Rationalism Archive

tgamble · 02-05-2002, 03:06 PM

creationists questions that evil stupid god hating bible denything evilutionists can't answer

Quote:

When there were no fish, what organism transformed itself into a fish? Who observed the transformation?

When an example of speciation was given for fish the response was

Quote:

they're still fish

He insists that all the different varieties of fish are just "adaption to the enviroment".

I can't be certain but isn't there a larger difference between two fish (say, a guppie and a shark) than there is between apes and humans?

Seems that would make apes and humans one "kind" since guppies and sharks are one "kind" based on LESS similarity!
<img src="graemlins/banghead.gif" border="0" alt="[Bang Head]" /> <img src="graemlins/banghead.gif" border="0" alt="[Bang Head]" /> <img src="graemlins/banghead.gif" border="0" alt="[Bang Head]" /> <img src="graemlins/boohoo.gif" border="0" alt="[Boo Hoo]" /> <img src="graemlins/boohoo.gif" border="0" alt="[Boo Hoo]" /> <img src="graemlins/boohoo.gif" border="0" alt="[Boo Hoo]" />

{tgamble, please refrain from putting inflamatory language in the topic heading. Thanks! -theyeti}

[ February 05, 2002: Message edited by: theyeti ]

Tharmas · 02-05-2002, 03:58 PM

A shark is very different from a guppie. For one thing it isn't a "real" fish in the sense that it doesn't have any actual bones, but only cartilage in its skeleton. You might be able to truthfully say that a guppie is closer to a human than to a shark! Someone who knows more about the subject may correct me on the actual evolutionary "distance" but I know it's true about a shark not being a true fish.

MarcoPolo · 02-05-2002, 04:12 PM

Quote:

Originally posted by tgamble:
When an example of speciation was given for fish the response was

What was the example?

tgamble · 02-05-2002, 04:29 PM

Quote:

Originally posted by MarcoPolo:


What was the example?

Does it matter?
<a href="http://www2.uic.edu/~vuletic/cefec.html#4.12" target="_blank">http://www2.uic.edu/~vuletic/cefec.html#4.12</a>

3,500 years ago, a small lake was separated from Lake Victoria by a sandbar. There are now five species endemic to the new lake; they have evolved from the original species in a geological instant (McGowan 1984:29). A population of Nereis acuminata that was isolated in 1964 was no longer able to interbreed with its ancestors by 1992 (Weinberg et al. 1992). New species certainly can emerge quickly.

According to brittanica fish are:

"any of a variety of cold-blooded vertebrate animals (phylum Chordata) found in the fresh and salt waters of the world."

wouldn't that include sharks?

Tharmas · 02-05-2002, 04:57 PM

Quote:

Originally posted by tgamble:


According to brittanica fish are:

"any of a variety of cold-blooded vertebrate animals (phylum Chordata) found in the fresh and salt waters of the world."

wouldn't that include sharks?

Sharks are of the Phylum Chordata but of the Chondrichthyes Class rather than Vertebrate
Class due to the lack of a bony spine. They're called fishes but only loosely. Their common ancestor with the guppies is a lot further back in time than our common ancestor with the guppies. Or so I've been led to believe. I'm not an expert...

DNAunion · 02-05-2002, 04:58 PM

DNAunion: Never mind.

[ February 05, 2002: Message edited by: DNAunion ]

Coragyps · 02-05-2002, 05:02 PM

According to <a href="http://phylogeny.arizona.edu/eukaryotes/animals/chordata/gnathostomata.html" target="_blank">this page</a> on the fantastic Tree of Life website, we are quite a bit closer cousins to bass than bass (or we) are to sharks. All three are Gnathostomata: sharks are in the Chondrichthyes side of the clade, and Billy Bass and I in the Osteichthyes. (None of this will catch on when you're telling your two-year-old what a horsey says, by the way.)
I'm sure that the dictionary (= folk) definition of a "fish" is based on "one of those swimming things," and not on any cladistics.

Cross post, but a short one!

[ February 05, 2002: Message edited by: Coragyps ]

Blinn · 02-05-2002, 06:13 PM

Cladistically speaking, if elasmobranchs (sharks & rays) are fish and bony fish are fish, then all tetrapods are fish too, since tetrapods and bony fish are more closely related than bony fish are to elasmobranchs.

From <a href="http://www.fishbase.org/manual/orders.htm" target="_blank">here</a>

Quote:

With Hennig, it became possible to distinguish paraphyletic groups (containing an ancestor and only some of its descendants) from monophyletic ones (containing an ancestor and all its descendants). Hennig thus gave birth to modern systematics, where the paraphyletic groups are finally rejected. For example, the old group Pisces ('fishes') is clearly paraphyletic as there is no character that can exclusively define fishes. There is a common fish ancestor: it is the animal that had the first cranium, between 500 and 600 million years ago. But half of the living descendants of this ancestor are not put in ‘fishes’. These are the tetrapods. If we decided to make fishes a monophyletic group, we would have to include tetrapods, and humans would be fishes. Another way to point out paraphyly is to stress that some members of a group are more closely related to other organisms than to members of their group. For example, actinistians (coelacanths) and dipnoans are more closely related to tetrapods than to actinopterygians. Actinopterygians, as ‘bony fishes’ are more closely related to tetrapods than to chondrichthyans. The term ‘fish’ therefore disappears from modern systematics and more precise terms are now available, all related to monophyletic groups. These terms are given here only for extant taxa! Craniates have the cranium. They are made of two sister-groups, the hagfishes (mixinoids) and vertebrates, which are divided into petromyzontoids (lampreys) and gnathostomes, the jawed vertebrates. In jawed vertebrates, the chondrichthyans (defined by prismatic calcified cartilage and pelvic claspers) are the sister-group of the osteichthyans (defined by a typical pattern of dermal bones: premaxillar, maxillar, frontals, parietals, etc.). Osteichthyans are divided into two sister-groups, actinopterygians (defined by the acrodine cap on teeth and other characters) and sarcopterygians (monobasal paired fins found in lobe-finned fishes and tetrapods). Sarcopterygians contain actinistians (coelacanths) and rhipidistians defined by the sinuous aortic trunk and many other characters. Rhipidistians are made of two sister-groups, dipnoans and tetrapods.

Similarly, if we call both gorillas and chimpanzees "apes," then we should also include ourselves as apes, as the chimpanzee is more closely related to humans than to gorillas.

[ February 05, 2002: Message edited by: zetek ]

Nic Tamzek · 02-05-2002, 06:34 PM

Quote:

Originally posted by Coragyps:
[Q]According to <a href="http://phylogeny.arizona.edu/eukaryotes/animals/chordata/gnathostomata.html" target="_blank">this page</a> on the fantastic Tree of Life website, we are quite a bit closer cousins to bass than bass (or we) are to sharks. All three are Gnathostomata:...[/Q]

If you want to hurt your head more, check out the <a href="http://phylogeny.arizona.edu/eukaryotes/animals/chordata/hyperotreti/hyperotreti.html" target="_blank">hagfish page</a>. Evidently you don't even have to be a vertebrate to be a 'fish'.

(So, is a lancelet a fish too?)

(and if tetrapods are fish, then dolphins and whales are fish too, so all those six year olds who were gently corrected in first-grade biology were right after all).

Nic

PS: While we're on the topic, let's have a vote. Fish, or not fish, in whatever sense that word means to you:

(<a href="http://www.nmsr.org/iconlink.htm" target="_blank">the back story</a>)

[ February 05, 2002: Message edited by: Nic Tamzek ]

[ February 05, 2002: Message edited by: Nic Tamzek ]

Coragyps · 02-05-2002, 07:01 PM

Nic - I vote not-a-fish, because it's not in the Texas Game & Fish Handbook.

But thanks for the link!

zetek - Thanks for that link, too. It's perfect for explaining what a clade is in terms of critters that laypeople will recognize.

02-05-2002, 04:58 PM	#6
DNAunion Veteran Member Join Date: Jan 2001 Location: USA Posts: 1,072	DNAunion: Never mind. [ February 05, 2002: Message edited by: DNAunion ]</p>

02-05-2002, 05:02 PM	#7
Coragyps Veteran Join Date: Aug 2001 Location: Snyder,Texas,USA Posts: 4,411	According to <a href="http://phylogeny.arizona.edu/eukaryotes/animals/chordata/gnathostomata.html" target="_blank">this page</a> on the fantastic Tree of Life website, we are quite a bit closer cousins to bass than bass (or we) are to sharks. All three are Gnathostomata: sharks are in the Chondrichthyes side of the clade, and Billy Bass and I in the Osteichthyes. (None of this will catch on when you're telling your two-year-old what a horsey says, by the way.) I'm sure that the dictionary (= folk) definition of a "fish" is based on "one of those swimming things," and not on any cladistics. Cross post, but a short one! [ February 05, 2002: Message edited by: Coragyps ]</p>

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02-05-2002, 03:58 PM	#2
Tharmas Regular Member Join Date: Apr 2001 Location: Dallas Posts: 184	A shark is very different from a guppie. For one thing it isn't a "real" fish in the sense that it doesn't have any actual bones, but only cartilage in its skeleton. You might be able to truthfully say that a guppie is closer to a human than to a shark! Someone who knows more about the subject may correct me on the actual evolutionary "distance" but I know it's true about a shark not being a true fish.

02-05-2002, 07:01 PM	#10
Coragyps Veteran Join Date: Aug 2001 Location: Snyder,Texas,USA Posts: 4,411	Nic - I vote not-a-fish, because it's not in the Texas Game & Fish Handbook. But thanks for the link! zetek - Thanks for that link, too. It's perfect for explaining what a clade is in terms of critters that laypeople will recognize.

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