The past couple of days I’ve been thinking a bit about the fossil record. I’ve e-mailed a couple of people some of my thoughts, but today something finally crystallized in my mind and I’ve come up with a paleontology study to propose. Obviously, this study is beyond my capabilities to perform myself, but I wanted to throw this out there to see what other people thought about it anyway (and who knows, if a paleontologist reads it and decides it’s worth studying then maybe I’ll get an actual answer sometime!).
First, this study begins with two assumptions:
Assumption 1: Most (animal) organisms that die will be very young, very old, or infirm; the “ideal” specimen (i.e., the age when the species is, on average, the healthiest) only dies in the case of random accidents, which are rare. As anecdotal evidence to back up my assumption here, consider your local city’s closest graveyard. If you go through it and look at the various tombstones, you will see that the large majority of people buried there are going to be very young or very old. Furthermore, a detailed excavation of the graveyard would indicate many people there died of diseases. However, if you look at the number of graves of, say, people aged 15-30 years, the vast majority of those will be people who died of non-natural causes (e.g., suicide, murder, car accidents, drug overdoses, etc.).
We also have evidence from the animal kingdom. Most victims of predators are the young and defenseless, the old who have weakened, or those who are otherwise already disabled in some manner. It is rare that a healthy animal will be killed by a predator (it still happens, but statistically this would happen far less often than any other type of death of a species).
Assumption 2: Most living (animal) organisms have larger populations close to the “ideal” specimen age than in any other demographic. In the case of the elderly, since organisms have to pass through the younger ages to get to an advanced state and there is the possibility of death in those younger ages too, it is obvious that there will be fewer elderly people than younger people. However, it is also the case that given the high infant mortality rate of most species and the fact that only a few will survive past the first couple of months (and also the fact that the youngest age ranges are typically far shorter than the length of the “ideal” specimen), there will usually be more of the “ideal” organisms living than the young. Again, this is not a hard and fast rule, but it is an assumption I think has some validity in the animal kingdom).
Hypothesis: If fossils have more “ideal” specimen types than very young, old, or infirm types, then organisms that are fossilized are almost always killed by catastrophic and indiscriminate “accidents” rather than due to factors such as predation, illnesses, or other more natural causes.
Note that under these circumstances, the “catastrophic and indiscriminate accidents” would not necessarily be such things as mudslides (although depending on the extent of the mudslide, one could qualify). The reason being is that if you have two organisms of the same species and a mudslide is heading toward them, the one that is the fastest will have greater odds of escaping than the slower one (this is the unobjectionable—and trivial—aspect of Natural Selection). Therefore, the very young, very old, and infirm would have a greater likelihood of dying in that mudslide than would a healthy organism.
This would not be the case, of course, in a widespread mudslide that would kill everything regardless of the speed of the organism involved. As such, minor mudslides would not qualify as a “catastrophic and indiscriminate accident” whereas a major mudslide would. Note also that the “major” and “minor” aspect of the mudslide depends on such things as the size of the organism and the location of the organism too. For instance, a meter high mudslide has a good chance of wiping out an entire colony of trilobites, but probably wouldn’t kill a Brachiosaurus. Further note that there could be other things than mudslides too (I only use the mudslide illustration since fossils are often explained as having been created by rapid burial of animals, such as during a mudslide).
The reasoning for my hypothesis is: Since most natural deaths will be of organisms that are very young, very old, or infirm (assumption 1), then if the fossilization happens after a natural death there should be far more young, old, and infirm specimens than “ideal” types. However, since there will be more of the “ideal” specimens alive at any one time (assumption 2), then if a catastrophic and indiscriminate accident occurred to create the fossil, a random selection out of the entire population has a greater chance of landing on one of the “ideal” specimens than on any other demographic. Therefore, if there are more “ideal” types of fossils than the very young, very old, or infirm, most (if not all) fossils are caused by catastrophic and indiscriminate events instead of natural and common causes.
If that reasoning is valid, the question is: What does the fossil record show? Are most fossils “ideal” types? Or are most fossils very young, very old, or infirm?
While this study would be interesting just for the sake of knowledge alone, there’s another reason it might be important. Think about the large size of many dinosaur species. After all, we’ve already noted that a mudslide could be one of these catastrophic and indiscriminate events for a colony of trilobites; but many dinosaurs were huge. If there are more “ideal” types of these large dinosaurs, then there would have had to have been many large-scale catastrophes to hit these dinosaurs (especially since modern assumptions are that it is very difficult to make a fossil in the first place, let alone to find it after it has been made, so there would have been many more of these catastrophes that have occurred than we have found fossils). And that, of course, would lead to the question of whether it is more plausible to assume a score of major catastrophes or that our assumptions about fossil creation are false.
By the way, I’d also note that if someone responds that it would be impossible to tell this from the fossil record, then it would be impossible to tell anything relevant to evolution from the fossil record too. That is, if we cannot tell the relative age of a dinosaur or whether or not it was severely ill from the fossil record, how are we to tell the relationship of that dinosaur to other similar-looking dinosaurs? Could they not be similar looking because they’re identical species but one had scurvy, for instance?
Just some thoughts.