I'd love to see what Einstein could do with physics now, but that's not going to happen.Getting my DNA tested has got me to thinking about, well, my DNA.  And your DNA.  And everyone else's DNA too.

You probably know that your DNA is unique.  Even if you're an identical twin, no one has the exact same set of DNA as you.

What is really interesting is that your DNA has most likely never been seen before.  And it will probably never be seen again.  You are a unique combination of genes for now and probably forever.

The reason for this is that humans reproduce sexually.  And sexual reproduction mixes up DNA in every generation.

First off, you get half your DNA from mom and half from dad.  That particular combination of DNA has never been seen before.

But even the chromosomes you get from each parent are unique.  Remember, we have two copies of each of our chromosomes.  So most of us have two copies of chromosome 1, two copies of chromosome 2, etc.

Each parent gives you one of the chromosomes in each pair.  But the chromosome they give is a mix of their pair of chromosomes.  So each individual chromosome you have is a new combination of DNA.

The end result is your one-of-a-kind set of chromosomes.  And because of how all of this works, the chances of your set of DNA popping up again are essentially zero.

Now this sort of mixing is absolutely critical for survival in a changing environment.  For example, imagine a species of plant that survives very well in dry conditions.  The plant reproduces asexually-basically, it clones itself each generation.  And it does great in the desert.

Imagine now that weather patterns shift so the plant lives in a wetter place.  The poor thing keeps cloning itself but since it isn't adapted to its new environment, it struggles to survive.  Eventually some wet-loving plant muscles in and our plant dies out because it couldn't adapt.

Sexual reproduction keeps this from happening by providing constant variety.  DNA is mixed and swapped every generation so that new individuals are made.  Some do well when it is dry and some do better when it is wet.  The plants are ready for lots of what Mother Nature can throw at them (as long as things don't change too quickly-think global warming).

The downside is that certain combinations of DNA will never be seen again.  For our plant it means that if the species stumbles on a perfectly adapted plant, none of its descendants will be as well adapted.  None of them will get the exact set of genes that its parent had.

It also means that human DNA combinations from the past won't be seen again.  Now this probably isn't a big deal for my DNA (or most everyone else's either).  But it means we will never have another Einstein, Bach, Galileo, Da Vinci, Picasso, etc.

This is too bad.  I'd love to hear what Bach could do with modern music.  Or what Einstein could do with physics now.

Related posts:

• No related posts.