I think what you're describing is evolution.
I mean, there's nothing stopping a lion from eating a plant, or a hippo from eating another animal. Things change. They evolve. New ways of living become standard eventually. If an atheist argues this can't happen, you should remind them that they probably do in some degree believe in evolution.
No. That is not evolution. It is
adaptation....which is not the same.
Change is NOT adaptation or evolution.
Adaptation is NOT evolution or change.
Evolution is NOT change or adaptation.
Those three terms are
absolutely NOT interchangeable.
Keep reading below for more on this....
So you are saying that a lion would rather starve to death, than eat anything other than vegetation.
If that's what you believe...
A true experiment would be to have lions starving, with nothing but that fruit or whatever else around... Just make sure the man isn't around... no vegetation either.
Then see what happens.
I always believed in evolution / adaptation.
Word games are what evolutionist play.
All Christians, Muslims, etc. believe in change - another word for evolution. We evolve every day.
I don't believe in the theory of evolution.
There is a difference, I hope you know.
It is not word play.
In terms of describing animals (or even plants, bacteria, fungi, etc...).....
Change is just change, and covers a massive slew or various topics, and is pretty much pointless to discuss here.
Adaptation is what one animal does, within the space of its own one lifetime, to alter it's own
behavior for improved life and/or life expectancy. NOTE: Adaptation may also include variation of gene
expression within one organism, within it's own one lifetime, but not a genetic change.
Evolution occurs over more than one generation and results in a change in the genome. This requires two components
in this order (First - A genetic mutation, and Second - a biological stressor). A genetic variation occurs in one or more offspring of an organism simply by chance (or even by some mutagen effecting the gametes of the parent(s)), and then the offspring are subjected to a
biological stressor.
Those offspring (the 2nd generation) who are capable of reproduction get a chance to pass along the new genetic variation, thus making the "mutation" more and more the standard for the survivors of the biological stressor, and are thus "evolved" to their environment better than offspring who don't get the genetic variation.
Continued below......
Suddenly change? What do you mean by suddenly change?
Does bacteria suddenly change to eating plastic?
Does drug resistance in bacteria happen suddenly?
So, no. For such bacterial feats of evolution, you have to consider VERY LARGE NUMBERS. E. coli bacterial colonies reproduce by mitosis, once every 20 minutes in optimal conditions. So. 1 bacterium becomes 2 in 20 minutes. In one hour there are 8 bacteria (2 ^3 because you had 3 reproduction cycles which double the population each cycle). Therefore, in one day (24 hours = 72 twenty minute reproduction cycles) a single bacterium has turned into 2 ^72 bacteria. That's 47,000,000,000,000,000,000,000 bacteria from one momma
. a.k.a. 47 sextillion bacteria.
DNA is copied pretty accurately, but on a rare occasion, an error is made in the copying process. Such an error is called a mutation. Most bacterial mutations are lethal, so all of that "daughter's" lineage never even happen. Thus at the end of 24 hours, we have less than 47 sextillion.
Supposing (purely hypothetically) that many lethal mutations occurred, along with several non-lethal ones. One of these non-lethal mutations makes the offspring glow purple, one that makes offspring glow green, one that lets the offspring eat plastic, and one that provides the offspring with immunity to penicillin) and at the end of the day, we have a total of 47 Quintillion bacteria. To simplify things, we'll also suppose that any one of these mutations cancels the bacteria from having offspring with any of the other mutations (yes sometimes that happens). But mutations are rare, so most of the bugs (bacteria) are just like great-great-great grandma the original.
Now we need that
biological stressor.
So we take the small teaspoonful of bacteria and drop them into a soup of water with very little food, but lots of plastic. The stressor is that those who cannot digest plastic for energy.....DIE.
One day later, we have a population of E. coli bacteria for whom 99.999% are able to eat plastic (thank you very much random
chance mutation +
stressor = evolution). No green glowers, no purple glowers,
no penicillin resistant daughters, and no daughters who are just like great-great-great grandma.
Note that the ones who could resist penicillin are now all dead. The stressor they faced had nothing to do with antibiotics. It was about getting nutrients from plastic vs starvation.
If the stressor was that they were trying to make an abscess and septic infection inside a human who was taking penicillin, then that's a different biological stressor, and only the penicillin resistant daughters would have survived to the end of the day. No plastic eaters.
If there had been daughters who were resistant to vancomycin (a different group of antibiotics) they would have died out too. Since in the environment I listed above, the stressor was Penicillin, not vancomycin.
So evolution occurs from generation to generation, with genetic mutations (most of which are lethal), combined with biological stressors in the environment that kill off those who were not simply lucky enough to have been born with the right genome.
Also, bacteria have VERY simplistic genomes and biological systems compare to multicellular animals, wherein a mutation in one system often has to be accompanied by mutations in other systems or else the offspring dies. For example, being able to functionally chew and degrade grass cellulose in grass cells with grinding teeth and longer/slower gullet, as well as biochemically converting cellulose to glucose inside the intestinal epithelial cells. One without the other won't convert a carnivore to an herbivore. And of course (thankfully) lions don't reproduce themselves by mitosis every 20 minutes.
So if we were to actually see inter-generation changes (evolution) in lions, we couldn't do it with a couple of weeks work in a lab, but it would take hundreds of thousands or millions of years in the wild.
Lastly, with enough mutations to a genome of any organism, it will eventually be no longer capable of reproducing with its EXTREMELY distant cousins of the same generation. And THAT is when we would consider them to be of two different species. They started with the same great-great ancestor, but enough change in the genome makes the gametes (egg and sperm) from connecting to one another to make a living offspring.
In this way, we are VERY DISTANT cousins of the other great apes. There was one great-great-great-.....grandma great "ape"; and over the many millennia, there were many mutations and stressors our ancestors (and off-branched relatives) were pitted against; leading to differentiation based upon survival for those environments.....so that gorillas, and baboons, and humans, and chimpanzees, and etc....etc...etc....other 'great apes' are what remain.