ASTROBIOLOGY PART-1

 What is Astrobiology? It is the search for life forms in other planets in the Universe.

We see and experience a multitude of life on the earth each day. We can also find what life existed in the past through biosignatures and the present life through its Techno signatures.

Bio signatures are signs that are left by previous life like skeletons, preserved parts in ice, mummies, and even the constructions that are made in the case of humans. These are all signatures, the proof that life did exist very much on a planet. Techno signatures are what we are creating today by making innumerable number of goods as well as usage of science which leaves out a debris.

So our identification of life is totally dependent on these two signatures. When we look in other planets or comets or asteroids or moons, we look for their bio signatures because so far we could not find any techno signatures which would have been more visible anywhere. So, we search around for latent bio signatures which are even made by bacteria and single celled organisms.

Of course on the earth the bio signatures are numerous as life here evolved 400 crore years ago by way of a single cell organisms. Let us have a look at the chart of life on earth:

450 crore years                                  Earth is formed

400 crore years                                  Single celled organisms

170 crore years                                  Microscopic multicellular organisms

 60 crore years                                   Small marine animals, seaweed

45 crore years                                    Fish, Land plants & insects.

35 crore years                                    First land vertebrates, trees

18 crores years                                  Dinosaurs, flowering plants

  5 crore years                                    First Lemur like primates

0.35 crore years ago                          First tool making hominids

0.03 crore years ago                          Homo Sapiens

Most scientists agree that the oldest species alive today is the horseshoe crab. This crab evolved 44.5 crore years ago, yet it is very much there today as it was then. Now what surprises me is why the Darwinian evolution bypassed it. While in the case of the human species which was born a mere 0.03 crore years ago this evolution accelerated and produced us. But why should that be so? We have no answer for that question.

This is the Horseshoe Crab.

Most species of animals exist only for a few million years. The dinosaur Tyrannosaurus Rex lived for just 3 million years.

The oldest plant species that exists today is the Gingko tree. They have been around for 27 crore years.

A Gingko tree lives hundreds of years, perhaps even 1000 years. In the genes and the rings of the Gingko balboa trees in China some are confirmed to be over 1000 years old.

The amazing thing about the Gingko tree is that the immune system of a 1000-year-old tree would be the same as that of a 20-year-old tree. Richard Dixon, a biologist from the University of North Texas compared young and old Dingko trees from 15 to 1300 years old and found that the immune system is the same for both. They find its genes contain no program for death. Old trees also produce just as many seeds and their leaves are as fresh as the young trees.

Scientists believe that the 4800-year-old Bristlecone known as Methuselah in Eastern California may have a similar pattern of genetic programming.

Scientists say trees like the Dingko can live forever, but eventually, the Dingko trees die but scientists are not able to find why?

The blue-green algae that still exists today and the Cyanobacteria are over 300 crore years old.