Skeptics Guide to the Universe Forums

The Skeptics' Guide to the Universe => Podcast Episodes => Topic started by: bort on May 27, 2006, 06:55:24 PM

Title: Podcast #38 4/12/2006
Post by: bort on May 27, 2006, 06:55:24 PM
News Items: Bill Nye, Tom Cruise, Time Travel, Global Warming, Happy Face on Mars;
E-mails: Evolution, more on the flood, the psychosomatic effect
Science or Fiction
Title: Podcast #38 4/12/2006
Post by: bort on May 27, 2006, 06:59:38 PM
Looks like Rebecca was right.  The egg came first.  According to "Chicken and egg debate unscrambled" (http://www.cnn.com/2006/TECH/science/05/26/chicken.egg/) on CNN.com:

Quote
Now a team made up of a geneticist, philosopher and chicken farmer claim to have found an answer. It was the egg.

Put simply, the reason is down to the fact that genetic material does not change during an animal's life.
Title: Podcast #38 4/12/2006
Post by: Paulhoff on May 29, 2006, 08:33:03 AM
I always thought that this was answered years ago, and it was just layman that didn’t get it, like believing that dinosaurs and caveman lived together at the some time.

Of course the egg came first, the parents where not as chicken as the egg, it is a thing called evolution.

Paul

 :D  :D  :D
Title: Podcast #38 4/12/2006
Post by: rebecca on May 30, 2006, 04:14:35 PM
Quote from: "bort"
Looks like Rebecca was right.  


And this is a surprise?

 :evil:
Title: Podcast #38 4/12/2006
Post by: Luna on June 03, 2006, 11:08:10 PM
But the "egg" coming before the chicken happened over hundred thousands of years. I would think.  :P Slowly but surely we got our chickies.
Title: Podcast #38 4/12/2006
Post by: Wonko the Sane on June 04, 2006, 12:09:50 AM
That is one of the semantic issues with evolution, by naming specific species we break them into false dichotomies when in reality it is hard to name a specific point where you could say "That is a chicken but it's parents aren't"
Title: Podcast #38 4/12/2006
Post by: Steven Novella on June 04, 2006, 07:02:53 AM
Right - the question really has no answer because the concept of species is artificial. "Species" is just a useful place-holder, there isn't really any such thing. There is no way to definitively define where one species ends and another begins over evolutionary time. So there really was no first chicken.
Title: Podcast #38 4/12/2006
Post by: Jay on June 04, 2006, 11:50:31 PM
Steve, lets say we genetically defined what a modern day chicken is taking into account the variations that normally occur(color, size etc).  If we had the ability to line up all of the ancestors of the modern chicken then at some precise moment in time the very first chicken as we know them was born.  So at some point in history a modern chicken came into existence. This does not define when the so called chicken species started, but it is when the FIRST chicken came to be.  How much of a genetic variation exists between humans? At what point would we consider someone not human, when they couldn’t breed with a real human?
Title: Podcast #38 4/12/2006
Post by: Paulhoff on June 05, 2006, 12:02:59 AM
Yea, yea, yea, now where’s the bacon.

Paul

 :D  :D  :D
Title: Podcast #38 4/12/2006
Post by: bort on June 26, 2006, 09:57:40 PM
Quote from: "Jay"
At what point would we consider someone not human, when they couldn’t breed with a real human?


I don't think there is any consensus on what is the true definition of a species.  The most common view is that it is this definition given by Ernst Mayr (http://en.wikipedia.org/wiki/Ernst_Mayr): "groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups"  This is a somewhat unsatisfying rule due to the fact that not all species reproduce sexually.  Also, it doesn't really take into account species that are connected over evolutionary time but never existed at the same time.  These groups could potentially interbreed, but could never actually accomplish it (without a delorean).
Title: Podcast #38 4/12/2006
Post by: Wonko the Sane on June 27, 2006, 03:29:07 AM
Quote from: "bort"
Quote from: "Jay"
At what point would we consider someone not human, when they couldn’t breed with a real human?


I don't think there is any consensus on what is the true definition of a species.  The most common view is that it is this definition given by Ernst Mayr (http://en.wikipedia.org/wiki/Ernst_Mayr): "groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups"  This is a somewhat unsatisfying rule due to the fact that not all species reproduce sexually.  Also, it doesn't really take into account species that are connected over evolutionary time but never existed at the same time.  These groups could potentially interbreed, but could never actually accomplish it (without a delorean).


Good point, If you had sex with a homo-erectus (wow I was able to type that without even a giggle) you could probably produce an offspring. A really ugly offspring.
Title: Podcast #38 4/12/2006
Post by: cyborganics on June 27, 2006, 04:18:09 AM
So hot.