Sunday, July 29, 2007

A creationism vs. evolution discussion,. Part 8

It's all in their heads...

I'll answer this question in more than one part, as this will get a bit long.

Question 14:
Why do carnivores present a problem for creationist theory?
Possible answers
  • They don't
  • Supposedly, all animals were originally designed as herbivores, so why were the carnivore modifications (like fangs and claws) created in the original animals?
  • Why would a just God have created killer animals?
  • They aren't mentioned in the Bible
The correct answer is Supposedly, all animals were originally designed as herbivores, so why were the carnivore modifications (like fangs and claws) created in the original animals?
In the supposed idyll of Eden, all animals were herbivores, implying that all were created as herbivores and were to remain so. Then, of course, Adam messed things up. But, if all the original animals were herbivores, why would they need fangs, claws, poison, webs? And why would herbivores need great speed, chemical defenses, quills or bad tastes?

Marcsana;s reply:
14. There are a few proposed models for carnivores, venom, and other such phenomena after the fall. One of them include [sic] genetic variation, that is, this was revealed in the genetic code after the fall. This poses much less of a problem for creationists than spontaneous generation and information-adding mutations is for evolutionists.

My reply:
This argument makes little sense and truly strains the bounds of credulity.

Let us look for just a moment at how many species would have had to change after the fall, according to this argument:
  • All living things that eat other animals, of course- that means not only carnivorous mammals, but the vast majority of bird species, almost all reptiles, all amphibians, and almost all fish (if fish are counted as “beasts of the earth,)
  • All parasites- and almost half of all species on Earth today are parasitic
  • All saprophytes- living things that survive on dead matter- all fungi, many invertebrates and some vertebrates

In other words, the vast majority of living things on earth.

Marcsana postulates that there are “a few proposed models” for such changes. As his primary information source appears to be the creationist website Answers in Genesis, (hereafter referred to as AiG) I looked up what they had to say about such models. So, rather than focus on the many, many problems with Marcsana’s theory (which would be a a treatise much too long for this blog!), I will focus specifically on those models.

The kinkajou
Kinkajous are South American members of the order Carnivora. AiG tells a story of a kinkajou researcher who needed to trap kinkajous for radiocollaring and tried many baits. Chicken didn’t work, nor did hard liquor. Finally, he hit upon using bananas- which worked. And his studies showed that the kinkajou was, after all, a fruit-eater.
AiG claims that “just because an animal has teeth usually associated with meat-eating, it doesn’t mean that it has to eat meat.” and thus implies that kinkajous are vegetarian but retain the skull structure of a meat-eating carnivore.
Let's play "Find the Kinkajou Skull!

Here are the skulls of various small members of the orders Carnivora and Primates. One of these skulls is of a kinkajou. Which one? Remember, according to the creationists we are looking for the one with long pointy teeth...

Now, let's look at three of these skulls more closely.

This skull is a marten, a member of the weasel family that is almost exclusively carnivorous. Note the length of the skull, which provides plenty of jaw attachments for strong muscles. Also note the very pointed molars, which serve as efficient meat-slicing knives. The canines are quite long, reaching down below the incisors.

This skull is a golden-headed lion tamarin, a small South American primate that feeds primarily on fruit. Note the more-rounded skull shape and the much smaller, non-pointed molars. The canines are still large, but not as big as the marten's.

This is a kinkajou skull. Note the rounded shape, smaller canines and small molars. The skull of the kinkajou definitely shows adaptations to a frugivorous way of life. The dentition of the kinkajou resembles the tamarin's more than the marten's.

Kinkajous are procyonids- members of the raccoon family. None of the procyonids are totally carnivorous; all eat at least some plant matter, and their skulls show adaptations to this.

Also, lest a totally incorrect myth be started, Roland Kays, the subject of the National Geographic article that inspired AiG , is no creationist. His scientific publications have been on topics such as how evolution shaped the social structure of kinkajou groups and how the kinkajou and primates are examples of convergent evolution.

Oh- and the answers to the skull quiz...
Row 1- American badger, black-footed cat, brown lemur
Row 2- Palawan stink badger, island gray fox, marten
Row 3- Ring-tailed lemur, kinkajou, golden lion tamarin

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