Topper wrote:The problems I commonly find with peoples thoughts on evolution is they don't understand that it is random. Mutations are random, some are adopted, other are not, some mutations hang around in the gene pool for thousands of years, others do not.
There is no apex species, there is no grand design (religion and creationism do have an issue with this point).
Stephen J. Gould liked to use the tape recorder analogy. Is evolution was music or video on tape and you rewound it, the odds are very slim you would hear the same tune or see the same movie twice.
Very important point! Yet I'd like to add that mutations that are a disadvantage usually do not hang around for as long as mutations that give you an advantage. But this is where people misunderstand survival of the fittest. Because what is an advantage in one situation may be a disadvantage in another. Which is why there is such diversity in nature. Chimps are stronger than us. We are smarter than them. Depending on the situation, one skill may be better, but it's not always the same one.
The genes for obesity and diabetes are another case in point. They seem very bad to us now, but in a setting with recurring starvation, the ability to effectively store surplus energy as fat deposits was gold.
Same with sickle cell anemia. Terrible disease, but you need two of the bad allele to get it, and the people who only carry one bad allele do not only not get the disease, but they also have a certain immunity against malaria, which is why this very bad gene has become so widespread in Africa. If you live in a malaria-infested region, kids with one bad allele have a better chance of survival than kids without one. The backside of this is that if both parents have one bad allele, 25% of their children will get sickle cell anemia, but maybe that's better than losing all of your kids to malaria?
So what may seem like a disadvantage may at times be an advantage.
Another misunderstanding is that humans came from monkeys or that dinosaurs became birds.
We share a common ancestor with monkeys, but our ancestors weren't monkeys.
The monkeys are our cousins, not our grandparents.
And the big hulky dinosaurs simply died out. They did not become birds.
But birds are really a type of small feathered dinosaurs.
http://www.ucmp.berkeley.edu/diapsids/avians.html
Today we know that many dinosaurs had feathers and that some had beaks. At the time of the great extinction, some of the small feathered dinosaur species survived, and today we refer to them as birds.
But they are just one tiny branch of the dinosaur tree. The big ones with teeth did not have any descendants. They just vanished. Probably because of a climate change.
