Spider DNA

Factual Questions
1

I just dispatched a small spider by smashing it with my index finger.
Because of this, I’m certain that I have a certain quantity of spider DNA spread on my fingertip.

Now I’m certain that that spider was skilled at many things, from spinning webs to eating the proper insects to procreating, and even running away from incoming flyswatters (though I caught it off guard).

Does this mean that the DNA smeared on my finger contains everything needed to create such a creature, complete with the full knowledge of spider life? Or is there more to it than that?

2

When properly embedded in the reproductive machinery of the spider - yes. The dna needs to be in a cellvand the biological machinery of an egg to turn into a spider.

And with proper qualifiers as to what ‘knowledge’ means in this context…

3

It’s quite complicated, but at some level all that information is smeared around like you think. Through very baroque and indirect mechanisms, the DNA contains instructions on how to grow a spider from a fertilized egg. DNA encodes proteins which make cells divide and specialize until you have a spider. Part of that developmental process specifies how its nervous system gets wired up, which determines instinctive behaviors. There’s a lot of feedback loops and tangled regulatory networks but it all works out if you start with the right conditions. It’s all quite baffling except for a few well-understood examples, but it’ll keep me and other biologists quite busy for as long as anyone can see.

Now, that information is only useful inside healthy cells with the right machinery to “read” the DNA and do useful stuff with the protein products. You might be able to extract some healthy egg cells from the smear on your finger, which if fertilized could grow new spiders.

ETA: More speculatively, some biologist could figure out how to extract smeared spider cells and convert them to stem cells or germ cells (sperm AND egg) and grow a spider like that. Nobody has done that with spiders (that I’m aware of), but similar things have been done with other organisms.