This is something I need to get off my back.
Creationists like to bring up “living fossils”. Living fossil is a non-technical term that generally means a extant species which has a roughly identical ancestor at a point far removed in the fossil record. Creationists think that living fossils disprove Evolution because those species had a tonne of time to evolve but never seemed to. If bacteria turned into human beings, why did some organisms stay the same?
This analysis misses the point in a very fundamental way.
The Theory of Evolution predicts “living fossils”.
Evolution is the process by which organisms undergo heritable changes across generations because of selection pressures in their environment. It requires several things.
1. Organisms with randomly distributed traits
2. Those traits must be heritable (ie, they can pass from one generation to the next)
3. Selection pressure
Selection pressures are things in the environment which make life easier or harder depending on the traits an organism displays. Selection pressures are things that allow an organism to thrive and reproduce if it is well-suited to its environment, or conversely makes life and reproduction challenging if an organism is unsuited to its environment. Where I live it is very cold in the winter (which lasts 6 months of the year). There are no iguanas here, and if a wild iguana showed up it would die come winter time.
But here’s the thing about environments – they change. Where I live there are very bountiful coal and oil reserves. In the river valley I can find strata of coal that are inches thick. Now you’ll have to take my word that an inch of coal started out as many feet of biomass, but over time heat and pressure pushes it down into a hard rock.
Where I live is boreal forest. The trees that grow are sparse and not very leafy. Evergreens do well. The boreal forest does not produce the 20 feet of biomass that would be needed to make that much coal.
It must have been nicer here once. And in fact, if you look at the fossils around it was. Huge tropical ferns can be found, as can hairless dinosaurs, many animals and plants typical of warmer climates lived here. The great tropical forest which covered this area produced the biomass that became the coal we find today.
There are very few if any living fossils here. Why?
Because the selection pressures are very different today than they would have been in the past. There was a huge glacier here many thousands of years ago, which would have buried my home under kilometers of ice. Before that my home was in the middle of a tropical forest. The things living in the forest would have died out when the ice age came, hence no living fossils to be found. When the environment changed suddenly a whole new set of selection pressures were in play, and life changed very quickly.
Now what if the environment had been the same the whole time? Well with the same selection pressures life changes much more slowly. The random variations take longer to have any marked results. If it cools off then hair becomes helpful quickly; they first creature to grow thick hair has a very strong advantage. But if things stay the same hair isn’t helpful so it doesn’t make a difference to evolution.
So evolution predicts that when the environment stays the same we should find only very slow, gradual changes.
Now think of a living fossil if you know one. Dr Carl Werner found lots of them. Listen to what he found. Shrimp. Crayfish. Crab, Prawn, Lobster. Dragonfly, Cockroach. Shellfish. I’m not so convinced about the parrot, I’d want to see the fossil and the dating before I’d put much stock in that. But the other ones I’ll grant in a second. Listen at http://www.youtube.com/watch?v=WlxqsUO42Ek
Let’s look at that list again. Shrimp. Crayfish. Crab, Prawn, Lobster. Dragonfly, Cockroach. Shellfish. Do you see a common thread?
Water. You got it. Why is that significant?
Land varies in temperature. The hottest recorded temperature on the land is 56.7 °C or 134 °F and the coldest is −89.2 °C or −128.6 °F. The temperature on land varies about 146°C or 295°F. On land there are Rainforests and deserts, tornadoes and hurricanes, mountains, plains, snow and ice.
What about water? The highest ocean temperatures recorded are around 30°C (around 88 °F). The coldest are where the ocean freezes, so 0°C or 32°F. The temperature of the water varies 30°C or 56°F. The land varies 5 times more than that. Underwater there are no deserts, no rainforests, and no tornadoes to be found.
Land is variable, water is relatively stable. It filters toxins and harmful radiation. It has a relatively stable pH level. Its temperature varies very little as the season change. The Oceans have changed very little since life first emerged. Life in water is much more stable.
Now remember my house, which went from tropical forest to glacier to 6 months of winter. It isn’t like the ocean in that it changes dramatically over time. Also, unlike the ocean, no living fossils are found here. What were those living fossils again? Shrimp. Crayfish. Crab. Prawn. Lobster. Water animals.
And this is exactly what the Theory of Evolution predicts. Here, where the temperature and environment have changed drastically we find drastically different life as we move through time. In the Ocean, where the environment has changed very little, evolution takes a very long time.
The long and short of it is that finding a shrimp fossil beside a dinosaur fossil isn’t surprising. Finding a squirrel fossil beside a dinosaur fossil would be surprising. Finding a shrimp fossil 100 miles from where we would have found water at the time would be surprising. But Dr Carl Werner doesn’t have any squirrel fossils to show us, and his shrimps were all underwater. And that’s exactly what an evolutionary biologist would have told him he would find.