cattle mutilations that's can't be attributed to predators,
You didn't mention crop circles... because they got caught making them.
Cattle mutilations that are not attributed to wild animals must be aliens?
I guess jack the ripper was an alien?
Generally the word mutilation is reserved for what people do to things or sometimes themselves... there is no need to suggest an alien did it... there are almost 8 billion other potential suspects on this planet.
A domestic cat shares 98% of its genes with a tiger; 96% shared between chimpanzee & a human. The DNA difference with gorillas, another of the African apes, is about 1.6%. Most importantly, chimpanzees, bonobos, and humans all show this same amount of difference from gorillas. A difference of 3.1% distinguishes us and the African apes from the Asian great ape, the orangutan. How do the monkeys stack up? All of the great apes and humans differ from rhesus monkeys, for example, by about 7% in their DNA.
..humans, chimpanzees, and bonobos are more closely related to one another than either is to gorillas or any other primate. From the perspective of this powerful test of biological kinship, humans are not only related to the great apes – we are one. The DNA evidence leaves us with one of the greatest surprises in biology: the wall between human, on the one hand, and ape or animal, on the other, has been breached. The human evolutionary tree is embedded within the great apes
DNA is basically shared by all life on planet earth and most of it does fuck all now... saying 96 percent of DNA is shared between two animals is actually saying quite a lot... we have four limbs and a head with two eyes and a nose and a mouth and two ears... we share that with apes and monkeys and cats and dogs and horses and sheep... are we related? Were they changed into what they are because a different set of aliens evolved from sheep or cats wanted them to be the dominant species and so they changed their DNA not knowing other ape based aliens had already done the same to help their team?
Why would these aliens care about making intelligent life... surely a planet with abundant water and air and the right temperature is exactly what they want without having to negotiate with its present owners... why would they create essentially what will be rivals to the earths resources?
Are they stupid?
If they want to play with DNA they could have taken some ape descendents and played with their DNA all they liked.
Waiting for a human to evolve on its own would take too long, so the aliens had to pick the most suitable ape specie & change its DNA.
Even if you are right... how long is too long... there is no point in manipulating the DNA if you don't then control the stock... a farmer doesn't pay enormous amounts of cash for high quality bull sperm to then fertilise small unproductive females in the hope the general quality of the herd will improve... he will pick his best females and hope to get a good bull that he can then raise better quality calves and of course sell his sperm for a small fortune too...
If we have this guiding hand... whether god or alien... why didn't it just happen overnight instead of over a period of millions of years... and WTF were they doing the first 4.5 billion years... in the scale of the age of the earth we are a minor afterthought.