The term “living fossil” is mainly used for describing the similarities and differences between the living organisms and fossils of extant specimens which virtually had unchanged structure and function.
The term living fossil was developed by an English naturalist Charles Darwin. He has described extensively about those living creatures that have remained largely unchanged for billions of years in one of his famous book “On the Origin of Species”. He also included those creatures which have not changed since their ancestors were fossilized. In his chapter on natural selection, he explained about the Species and its group which is termed as aberrant.
Living fossils are one of the best evidence from which various living species can be proved to be identical. If both present living and fossil creatures are similar and identical, then the older fossils are found to be present. Darwin believed that all living fossils were exceptional and strange. We can easily identify many fossils as they represent animal that no longer exists on Earth
According to the Charles Darwin research, these animals haven’t stopped evolving. Each and every living species have continually modified to changing environments, raising and dropping of temperatures and other changes in atmospheric composition and conditions. These species have settled to their environmental controls in which they have achieved a competence peak in environments that constantly strengthen certain physicality. Some fossils show no identical features, therefore it is an evidence that the creature once existed. These extinct creatures are the reminder to the world which is losing other living species.
There are exactly dozens of living fossils; here are some of the most fascinating:
Bacteria, Algae, and Protozoa
The earliest living things believed to have evolved are bacteria algae, followed by single-celled organisms such as amoebae. Bacteria are tiny, minute, organisms which can survive in such harsh environments only by carrying out complex chemical processes.
Even though cyanobacteria are not often considered a living fossil, it is the first form of life to evolve on Earth. The strains of bacteria are one of the most successful groups of organisms on this planet has ever seen. These cyanobacteria provide the most ancient records of life on Earth.
The fact which is ever seen or believed is that the chemicals can evolve into a cell, and the single-celled organism can develop into multicellular organisms. The fact that jellyfish and arthropods are discovered in layers is believed to be younger than fossil rocks and it is not evidenced that the rock organisms turned into arthropods or jellyfish.
The comb jelly which is a gelatinous animal first emerged 700 million years ago. They resemble like striped jellyfish or jelly blobs which move throughout the sea with the help of cilia.
Another example of quintessential living fossils is the Horseshoe crabs. They first emerged around 450 million years ago and it resembles crustaceans but they belong to the family of Chelicerata subphylum.
Living plants vary from small, minute mosses to large trees. The same applies to fossil plants and no matters how old they are. They are recognized as plants as they have not changed; besides some have shrunk. The decrease in size and the shape of the trees is not evolution. The small versions are the same kind and in the same way.
For instance: The bonsai trees are the same as the large versions which were living out in the wild.
The most famous living fossil tree – Wollemi pine is believed to be extinct 200 million years old and as per the new discoveries, it is found that the same species is alive in Australia. A specimen of this tree was planted in Kew Gardens in 2005 by David Attenborough.
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