Down the no-rabbit hole

My tween daughter kept asking if we could get a rabbit, figuring the answer would either be yes or no, giving her a 50 percent chance each time she asked. After 28 or so negative replies, I gave in for reasons of peace and my sanity.

It also afforded me the chance to use our new pet as a springboard into a lesson about evolution. Southeastern Oklahoma State University biological sciences professor Stanley Rice wrote that evidence for the field rests on the convergence of multiple independent lines of evidence. He credited early 20th Century British scientist J.B.S. Haldane with noting that evolution could be disproven by means of a Precambrian bunny. The lagomorph in question was just a placeholder animal, so a cat, dog, mouse, elephant, or frog would suffice. In truth, any mammal, amphibian, or land animal appearing amongst other Precambrian fossils would be strong evidence against the current school of evolutionary thought.

Rice reminds us (or informs, for those of us who played tiddlywinks during high school biology) that the Cambrian featured lots of really cool gargantuan creatures they are still making blockbuster movies about more than 500 million years later. By contrast, Precambrian strata have no large animal fossils because no such creatures had yet evolved. If that strata were produced by a flood that wiped out large animals that had been created no later than 2,000 years prior, it should have some giant critters embedded within.

While Noah’s menagerie was floating about, its members’ less fortunate relatives would have eventually became part of the lowest fossil layers. Rice wrote that a worldwide flood would yield a fossil record with mostly fish at the bottom and primarily mammals on top, but that there would be a smattering of exceptions. Or surely at least one. He mused, “The raging flood waters would have drawn large animals down into the bottom layers. Just one. Just one Precambrian bunny. That’s all it would take.”

Alas, there is no such Darwin-defying rabbit.

Now onto rabbit food, the plants. If all plant fossil deposits resulted from a flood, one would expect wetland plants on bottom and their mountain counterparts on top. While this is largely the case, there are exceptions. Rice asks us to “consider the small wetland plants of the Ordovician and Silurian periods. None of them are the flowering plants that are the most abundant plants on the earth today. Find me a Silurian weed from, say, the aster family or the mustard family. Today, wetlands have little pickleweeds in them, from the spinach family of flowering plants. Yet somehow there were no plants that had flowers in the Ordovician or Silurian wetlands.”

The fossil record also reveals one of the strongest individual pieces of evidence for evolution, Tiktaalaik. While any fossil is, strictly speaking, a transitional one, Tiktaalik’s mix of fish and amphibian features make it the type of animal that evolution deniers long insisted would never be found. Further, researchers digging through sedimentary layers found it in the precise place one would expect it to be were it the descendant of fish and an ancestor to amphibians.

These theories work with the tiniest, most simple life forms as well. Single-celled algae called foram are housed in calcium carbonate shells, which linger once the foram cell has died. These shells come in different distinctive shapes and each represents a specific time and place in geologic history. That they appear more or less in order within strata points to evolution, whereas if they had all been wiped out in a flooded, microbiologists would find them randomly scattered.

Then there is the matter of where the surviving animals went after the flood. Endemic species like kangaroos would have had to travel from Turkey to Australia, making for two very determined marsupials. A common creationist retort is that maybe it was the distant offspring of these kangaroos that eventually made their way Down Under. But if so, this hopping ancestral line did so without leaving one fossil behind. And this scenario would had to have repeated for every endemic species, such as Antarctica’s penguins, Papua New Guinea’s cassowaries, and South America’s guanacos.

The same pattern holds true for all major animal groups that live on continents that have been separated for millions of years. But it is not true for continents that have been connected relatively recently. Rice explained, “This is why many of the animals of northern Europe and Asia are similar – and in cases, such as reindeer and elk – the same as those in North America. Only about 20,000 years ago, the Bering land bridge connected Asia and North America and allowed large mammals to migrate.”

Plants follow the same pattern. The major plant families of the southern continents are not the same as those of the northern continents. And, once again, Australia its own beast – or fern, maybe, since we’re addressing plants. It has some flora the other continents don’t.

So that’s how we know. Now If I could only get my daughter to listen to this.

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