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[music]
You guys had questions, I've got some answers. It is time for another Ask Joe Stuff!
[music]
Ok, let's get this show on the road.
o-dawgtheinvincible asks "What are the odds that someone has existed before that had my
exact genetic code? Do I have a medieval or Roman twin?"
Well, even identical twins or clones aren't completely genetically identical. Even though
they might start that way, through development they might get 300-400 or even more genetic
mutations, and a lot of the difference that we see in identical twins is due to gene expression,
and not the actual gene mutations themselves. Consider this: each parent gives 23 chromosomes
to either its *** or its egg, that means there's 8.4 million combinations that those
can shuffle up. Combine two parents and you've got a 1 in 70 trillion chance, and that's
without any of that genetic crossover that goes on in meiosis. So while I guess nothing
in the universe is completely impossible, this is probably about as close as it gets.
bazingorz sent in a question by Instagram: How likely is a zombie apocalypse?
Not very likely considering that zombies are not real. But that doesn't stop people from
researching it. Epidemiologists actually use zombie films as a way to predict disease outbreaks,
and it turns out that film directors have figured out exactly when to bring in that
big army to kill the zombies in order to save humanity, and it lines up pretty well with
what we see in actual diseases. There's a pretty good article about that I'm gonna put
down in the description.
fesworks asks: Please explain why a piece of bread will soften up hardened xmas cookies?
Ah, contrary to popular belief, things don't get stale because they lose water. It's actually
the starch granules inside that bread or those cookies crystallizing from its gelatinous
form. Christmas cookies are full of sugar, and sugar is what we call hygroscopic. Which
means that it wants to hold on to water and it sucks it out of the atmosphere. So if you
put a moist piece of bread in there, it actually sucks up the water from the bread, and gets
'em all soft again.
martin-chan asks: Why does cheese smell like feet?
Martin, are you sure you want to know the answer to this question? Because you can't
unknow what I'm about to tell you. Cheese smells like feet because feet smell like cheese,
because they have a lot of the same bacteria. In fact, there's one species called brevibacterium
that makes a compound called methanethiol, and it's found both between your toes and
in a lot of pungent cheeses. There was actually a study done at Brown University where when
people were blindfolded, they couldn't tell the difference between Parmesan and vomit.
Man, we should do a whole episode on cheese. Hey guys, let's do a whole episode on cheese!
@alexawhitaker asks: How did you initially fall in love with the field of biology?
I don't really remember the exact moment because I can barely remember what I had for breakfast.
Physics gets all the love, and I know it's really cool to understand like the workings
of the universe and basic matter, but biology is the study of a conscious being, understanding
itself. Intricate chemical machinery that evolves and changes over time all due to inanimate
forces of natural selection, it just completely blows my mind. One thing I'll tell you, I
remember the first time I saw a cell under the microscope, and since that day the more
I've learned, I'm amazed that anything works at all. That's why I love biology.
sinkhership asked: Do you have a favorite scientist?
Man picking a favorite scientist is like asking which one of your children you love the best,
but if I had to pick one, definitely Richard Feynman. He was the nest explainer ever, he
was funny, he was charming, he could tell the best stories, oh and [music] he won a
Nobel Prize, he was a brilliant guy. I'll tell you what, I'm just gonna put a link to
a series he did called "Fun To Imagine"down in the description, watch that and I promise
you will fall n love with him too.
Thank you to everyone who sent in questions for this "Ask Joe" remember you can always
ask me questions at itsokaytobesmart.com email address and the Twitter handle are down below,
and subscribe by clicking on my head, I guess, and you can learn new fun science facts every
week.
Thanks a lot and stay curious.