Our Earth is full of coloured creatures like insects, birds and cool amphibians. But why to extinct them? Are We too selfish?There have been many hundreds of anthropogenic extinctions in the last 500 years. Some examples indicate the extent of the extinction problem. In mammals, 76 species such as the Steller sea cow are extinct, 2 extinct in the wild (i.e. surviving only in captivity, SOC hereafter), and 29 possibly extinct. At least 134 birds, such as the passenger pigeon (Ectopistes migratorius) are extinct, 4 are SOC, and are 15 possibly extinct. Amphibians have been severely affected, and 159 such as the golden toad (Incilius periglenes) are extinct, one SOC, and 120 species are possibly extinct. In the case of reptiles, 21 species are considered extinct and one SOC, whereas among fishes 91 species are considered extinct.
Archive for the ‘Review’ Category.
Though it seems impossible to colonize galaxy at sub-light speed but without FTL travel we can still colonise the universe at sub-light velocities[ using self replicating probes and Bioprograms which I’ve discussed recently], but the resulting colonies are separated from each other by the vastness of interstellar space. In the past trading empires have coped with time delays on commerce routes of the order of a few years at most. This suggests that economic zones would find it difficult to encompass more than one star system. Travelling beyond this would require significant re-orientation upon return, catching up with cultural changes etc. It’s unlikely people would routinely travel much beyond this and return.
Jupiter has so many moons which may possibly harbor exotic life including major candidates for exotic life Europa and Ganymede. Although Jupiter itself is suggested as to be capable of harboring jovian life. But today I read a article published on cosmology magazine which suggested that life could be possible on Jupiter’s moon Io.
After the big bang planet started to evolved. Then life emerged from randomness and due to carbon water combo or life came from extraterrestrial planet? Billions of years before Earth or our solar system were formed, space-journeying viruses and extraterrestrial microbes were deposited on planet after planet and continually exchanged DNA with species living on other worlds.
When we are going to talk about alien life, we have to presume some assumptions. Circumstantial evidence indicates alien civilisations are very few and far flung in the universe. I have pointed out that the easiest way to explore the universe is send out self-replicating space probes . Within a cosmologically short period of co-moving time (ie millions of years) we could colonise the Milky Way and the rest of the Local Group. The arrival of such a probe at a star system would preclude and supersede local biological evolution. Since life on Earth has evolved over billions of years then we can’t expect (statistically speaking) to find civilisations within our local group. Where are the aliens, asked Fermi. Many megaparsecs away!!