News about Neanderthal genes in modern humans makes you think about the whole concept of species and extinction. Among modern humans, 1-3% of our genes are Neanderthal, but these are not always the same genes in every person, so if you summed up the Neanderthal genes found in modern humans, you could reconstruct 20% of the Neanderthal genome. Someday we could recreate Neanderthals. Would that be a good idea?
The idea of a species is a human construct. As our understanding of genetics improves, we begin to see how fluid the concept really is. You could argue that Neanderthals and humans are/were the same species. Polar bears and grizzly bears could be called the same species; they just come in different colors and a few other variations. Maybe even horses and donkeys. The boundaries are not clear.
Any species has lots of variety within its boundaries and the “species” changes every day. This might seem a little strange, so let me explain. A species is made up of individuals, each one of them is a little different genetically than all the others. Every day some die and others are born. Those exiting are different in some ways than those entering the species. This is one of the requirements of evolution. Over a short time, things don’t seem to change much. Over a long time, they change a lot.
This kind of complexity and evolution explains many things beyond biology, BTW. This kind of emergent behavior can help explain development and change in almost every system, such as languages, cultures etc. But this is another story.
Anybody who has seen Jurassic Park is familiar with the theory of species restoration. It may soon become a widespread reality, although maybe not with dinosaurs. This will present us with various dilemmas. What should we do with restored species? Some will probably be uncompetitive with their evolutionary descendants; that is how went extinct in the first place, but others might displace their modern cousins. If we restore an animal, does it deserve protection as an endangered species? These choices will be on us sooner than we think. Somebody will restore a long dead species very soon; somebody probably already has.