<Why do we constantly find fossils of dinosaurs and fossils of birds, but never the countless in-betweens?>
First, most fossils are found in "beds" where ALL AT ONCE a cataclysm produces a massive kill off. Think of it as a Hiroshima-like event. It could be a ecological disaster, or come from above like a meteor or comet fragment. For whatever reason, a bunch of things usually die all together. Unless it happens when intermediates are around (usually a short period of adaptation, these would not be present). It isn't always the case of a common die off, but most often it is.
Secondly, a set of geological processes has to preserve the record. This is a very difficult task because unless it is s major die-off, bones are spread around like yesterday's trash by the predators. Unless it kills the predators too. The rotifers remove any soft tissue - except by other even more rare processes. So unless the thing you are looking at is in the hard tissue, it will be missed.
Thirdly, evolution doesn't happen gradually. In Geology there is something called "punctuated actualism". In biology that is mirrored by "explosive radiation" where all of a sudden the rules change and creatures have to start changing (and quickly). It is much easier to see in plants like genus of Quercus, the white oak. It has GAZILLIONS of intermediate species. There is a heck of a lot more plant material fossilized than animals. And more biomass of plants. What you are looking for IS in the plant kingdom for this reason.
Finally, someone has to find it. When one considers that the vast majority of the surface of the Earth is recycled material, eroded, ground to bits by faulting, cooked and melted by vulcanism, and of a very considerable thickness, it is astronomically unlikely that we should find anything at all without removing a lot of material.
It's like looking at the outer skin of an apple and proposing that the entire apple is filled with a shiny red material and that as a fruit, it has no seeds because you haven't found them yet. Bad analogy because the amount of surface exposed material is a FRACTION of the ratio of apple skin to interior. Anyone who understands geology knows this. There are structures that only one group of animals have, all closely related and arising from a single animal which only has this. Your expectations are naive. It's like asking "Why don't I find a snowflake exactly like the one I had as a kid". You might find one the same general shape, but not exactly what you want. I think your expectation for "transitional species" is the same. |
