Sunday, August 5, 2007

A creationism vs. evolution discussion,. Part 9

Now back to Marcsana’s comments on my quiz.

Question 17:
Creationists claim that fossils are the remains of the living organisms that perished in Noah's Flood. The Karoo Formation in Africa contains the remains of over 800 billion vertebrate animals. If this were a true representation of how many vertebrates were killed in the flood, how many vertebrate animals would each acre of land on Earth have held at the time of the flood?

Possible answers:
The correct answer is 2100.
Obviously, this would be a very crowded Earth!

Marcsana’s comment:
17. You may want to recheck yourself on the Karoo fossil graveyard. There is no problem here at all. IF the 800 billion number is accurate (which is an educated guess at best), there is still not a problem.

My comments:
First of all, just a FunTrivia editorial comment- I don’t allow numerical questions in Sci-Tech any more (this quiz was written in 2001) as numbers are so subject to quibbling.

Secondly, note that Marcsana provides absolutely no evidence to show that this is “not a problem.” As usual, his probable source turns out to be Answers in Genesis- “The Karoo vertebrate non-problem- 800 billion fossils or not.”

The article is primarily an example of what I mentioned above- quibbling over numbers. As usual, it lacks any scientific merit.

This is an in-depth explanation of the Karoo problem:
Too Many Animals

Whitcomb and Morris cite with approval a paleontologist who estimates that the Karroo Formation of southern Africa is believed to contain 800 billion fossil vertebrates with an average size of the fox.38 There are 126 billion acres on the surface of the earth. Only 30 percent of this area is land, giving a land area of 38 billion acres. If 800 billion animals were spread over the 38 billion available acres, there would be 21 animals with an average size of a fox, per acre, from this deposit alone. This does not include all the vertebrate fossil deposits throughout the rest of the world. Assuming that the Karroo beds are only 1% of the fossil vertebrates in the world (the Karroo beds occupy much less than 1% of the sedimentary column) means that 2100 animals per acre occupied the preflood world. Since an acre is 4840 square yards, each animal would have only 2 square yards, or 18 square feet, of territory. That is an area only 4.2 wide by 4.2 feet long. This can be put in a setting that most Americans can understand. The average house lot is about a quarter acre. Can you imagine every house in your neighborhood surrounded by 525 hungry animals the size of a fox? I, for one, would not venture out of doors. Obviously this is far too many animals. [I don't believe Morris' numbers but if they are right, then this is the consequence .]

In the article that Marcsana cites, the creationists claim that there is no problem because there would have been plenty of food for all those hungry reptiles:

Those anti-creationists who proclaim that such
population densities are impossible are in for a rude shock.
Simple studies of actual reptile population densities show
that the requisite densities of reptiles not only are possible
but do in fact exist even on todayís earth.11 It should be
stressed that these are locally-supported populations and
not local congregations of animals. And such population
densities are nowhere near the levels needed to tax the
requisite vegetation required to support such a highly-
populated food chain, much less the sunlight necessary
to support the ecosystem.12

Unfortunately, cites 11 and 12 in this paper are to another creationist paper authored by one of the authors of this paper, not an independent cite to verifiable information. Without any independent verification, these claims are far too ludicrous to be taken at face value.

So let’s make a brief review of what is known about the Karoo animals’ sizes and how that compares with reptile densities today.

A table of the main reptiles found in the Karoo formation lists the following genera- I have added comparisons to the sizes of modern-day animals:

  • Aulacephalodon- cow
  • Cistecephalus- mole
  • Cynognathus- wolf
  • Daptocephalus- otter
  • Diademodon- small cow
  • Dicynodon- wolf
  • Diictodon- fox
  • Dinocephalian- rhinoceros
  • Endothiodon- wolf
  • Eodicynodon- wolf
  • Kannemeyeria- cow
  • Lystrosaurus- wolf
  • Pareiasaurus- cow
  • Pristerognathus- wolf
  • Procolophon- lizard
  • Robertia- rabbit
  • Tapinocephalus- rhinoceros
  • Thrinaxodon- fox
  • Tropidostoma- wolf
  • Whaitsia- wolf

So, most of the species found in the Karoo were actually quite a bit larger than a fox. Of course, if 99% of the animals were the lizard or rabbit-sized ones and only 1% were the larger animals, then that could skew things a bit. So it’s important to know which fossils are most commonly found in the Karoo. Sources state that the fox-sized diictodon and wolf-sizd dicynodon are the commonest fossils.

So an estimate of at least fox-size for the average animal size appears accurate. The average red fox weighs around 6-15 pounds; let’s take an average of 10 pounds for simplicity’s sake. So, 2100 fox-size animals per acre would weigh 21,000 pounds, or 10.5 tons. That’s an elephant on every acre!

Well, what about the assertions that some areas support huge populations of reptiles? They do- but those reptiles are very small. I did some research looking for very large densities of reptiles, and found a couple of studies:

Individual and population energetics of a lizard on a Mediterranean islet
Population density in the lacertid lizard Podarcis lilfordi on the Mediterranean islet of Nitge, Menorca, Balearic Islands, was found to be 12 190 ind · ha-1 (SE, ±2135), exceeding densities reported for other island or mainland lizard populations.
This equals 30,109 lizards per acre.

10 grams would be a large weight for one of these lizards (the average is about 5-9 grams) but even with this generosity, 10 grams per lizard x 30109 lizards = 66 lbs per acre.

Population Density and Energetics of Lizards on a Tropical Island
This study looked at the weights and numbers of lizards in a fertile tropical habitat.
Population density and biomass estimates of these populations were
1318, 561, and 4200 individuals/ha and 4.2, 15.4, and 3.5 kg/ha, respectively.
Although these densities are not exceptional for other Carribbean islands,
they greatly exceed lizard densities reported for mainland communities.
That’s 19-83 pounds of lizard per acre for this study. We are a long way from an elephant!

So the creationists have a long way to go to explain the density of the Karoo fossils. There are other problems with their theories that we have not even dealt with here, such as why such a gigantic accumulation of fossil remains contains only reptiles (and a few amphibians,) all of which are now extinct, if it supposedly represents a nearly-instantaneous burying of all living animals in the area? Why are there no fossils of lions, impalas, Cape buffalo, kudu, or any other animals that now live in the Karoo?

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