Thousands of birdhouses were installed by the Ohioans. I also had one built. The bird’s population bounced back. The birds came to my birdhouse also and started building the nest but, before they could complete it, the House Sparrows drove them away

 

Dinosaur Fossils and Adaptation by Animals
By Dr Khalid Siddiqui
Ohio

 

Everyone has seen dinosaur fossils in the museums and is familiar with the concept of Adaptation by the Animals. But unfortunately, most people are unfamiliar with the true meaning and significance of these two phrases.

⁠Dinosaur Fossils: Dinosaurs lived during the Mesozoic Era (252 to 65 million years ago), often called the “Age of Dinosaurs”. So, even the newest fossils are at least 65 million years old. The dinosaur’ skeletons that we see in museums all over the world are not real bones but rocks (minerals) in the shape of bones. Permineralization is the process that converts dinosaur bones into minerals.

This is how the process works: When a particular dinosaur died close to a water source like a river or pond, then its soft tissues decomposed quickly, and the bony skeleton was slowly covered by sediment by the wind or water waves. Over the next hundreds of thousands of years, this sediment hardened. Then the water seeped through the sediment very slowly, and over another hundreds of thousands of years leached out the bones completely leaving behind a cavity where once the bony skeleton was. During the next hundreds of thousands of years, the same water slowly deposited the dissolved minerals in this cavity. In another hundreds of thousand years, the whole cavity got filled up by minerals that the water had deposited, where once the bony skeleton was. By that time the encasing sediment further hardened into rock. So, the final result is the mineralized skeleton encased in rock. These are finally discovered by the Paleontologists who chisel off the rock and expose the mineralized bones.

The original bones of the dinosaur disappeared millions of years earlier. The dinosaurs went extinct around 65 million years ago. No organic material can survive that long.  So, no DNA can be extracted from these inorganic bone-shaped minerals.

The entire bodies of several Woolly Mammoths (ancestors of elephants), trapped in permafrost, were excavated from Siberia in 1999 with intact soft tissues and bones. Although these were only a few thousand years old, any viable DNA still could not be extracted from their tissues.

Everyone has heard the sentences like ‘animals must adapt to the changing circumstances (food, climate, environment, etc.) otherwise they will perish.’ The way it is projected is as if the animals are guilty of not changing their lifestyle to adapt to the changes. The burden is put on the animals to bring about a change in their behavior. However, no animal other than humans is capable of bringing about this change in its behavior. Animals (other than humans) are hard-wired to lead their lives in a certain way. They can’t change. Nature has to come to their help. Here is how it works. For example, an animal species is living comfortably in an area but, gradually, the climate of that area is getting colder and colder every year. After a few years, it would get so cold that the animals wouldn’t be able to survive there. However, in every generation, some of the offspring are born with various types of genetic mutations – healthy and unhealthy. So, with good luck, one or a few members would be born with the mutated gene (like the genes that could make them grow hair over the body) which could resist the cold weather. Only those isolated animals from that generation would survive and will be able to pass on their favorable altered genes to the next generation. So, the descendants of this generation will exist, and their ancestors will die out and eventually become extinct. This is called Adaptation by Natural Selection. The animals’ genes have to change to pass on the favorable traits to the next generation.

The bottom line is that animals (including humans) cannot bring about that change in their genes. Only Nature could throw in a few animals with favorable genes into the population for the species to keep going. As opposed to animals, humans can do something else to adapt, i.e., they could wear warm clothes, install heating, etc. to overcome the cold. But the next generation would still be unchanged and would need all those artificial means to survive.

However, the process of natural selection works in humans also. When people moved to colder northern territories a long time ago, a vast majority of them couldn’t tolerate the bitter cold climate. They either left for southern warmer areas or died. Only a few who possessed gene variants that promoted heat-generating body fat adapted and survived. Their descendants are the Eskimos.

But Nature doesn’t always come to the animals’ rescue. Here is an example: Eastern Bluebirds are one of the most beautiful birds in my state of Ohio. The bird, however, is hard-wired to build its nest in the hollow of a tree trunk, only if the opening is 5 to 6 feet above ground, the diameter of the hole is 1.75 inches, and the floor of the nest is 4 inches square. The female will not lay eggs unless it finds the proper nesting place. Because of deforestation, human encroachment and, industrialization the trees are being cut down, thereby, reducing the chances of Eastern Bluebirds finding the required nesting place. The National Audubon Society (NAS) recorded a definite decline in the bird population. The hope was that some mutated form of chicks would be hatched, who would not require such a stringent nesting place, early enough before all the birds died out. About 15 years ago the numbers reached that critical point. Then NAS requested all its members (like me), and others, to set up birdhouses, with those specifications, in their backyards. Thousands of birdhouses were installed by the Ohioans. I also had one built. The bird’s population bounced back. The birds came to my birdhouse also and started building the nest but, before they could complete it, the House Sparrows drove them away. So, I was not able to make any contribution. If it was left up to Nature, then the Eastern Bluebird would have been extinct by now.

Here is another example of artificial selection: Most African elephants (both male and female) are born with tusks but, at the same time, some are born without any tusks (this is because of some genetic mutation in them). By the end of the 19 th century, almost all the African elephants (the ones with tusks) were killed for their tusks. Only those without the tusks were left untouched as they didn’t have any commercial value. They actually flourished. But in the 20 th century, the conservationists got together and forced the African governments to ban elephant poaching for the tusks. The elephants with the tusks slowly bounced back, but their situation is still endangered. So, if it was not for human intervention, there wouldn’t have been any elephants with tusks left in Africa.

In conclusion, the way animals adapt to their environment in an ecosystem is mainly through genetic variation and natural selection offered by Nature to develop adaptive traits and behaviors for better survival and reproduction.