transcript: It's a question that has perplexed humanity from as early as the ancient Greeks
all the way to the 21st century and we're still dying to know Which came first? The chicken or the egg? The question would be simple if we took it literally Egg laying animals existed
far before chickens came about So technically, the egg came before the chicken But this question, better worded as
"the chicken or the chicken egg?" focuses more on the cyclical cause and consequence That is - if a chicken is born from an egg where did the egg come from? Another chicken, presumably, which
too must have come from an egg So which came first? On the one side we have Team Chicken Research suggests that the protein
essential for the formation of chicken eggs (OV-17) is only found in chicken ovaries Without it, the chicken egg shell could not be formed So, without a chicken, you
technically can't get a chicken egg But this all depends on the nature and
definition of a chicken egg in the first place After all, is a chicken egg an egg laid by a chicken or one that simply contains a chicken? Obviously the OV-17 bearing chicken
had to come from somewhere But if an elephant laid an egg from which a lion hatched would it be an elephant egg or a lion egg? This leads to the other side of the story - Team Egg During reproduction, two organisms pass
along their genetic information in the form of DNA but the replication of this DNA is never 100% accurate and often produces minor
changes for the new organism These small mutations in DNA over
thousands of generations create new species' but these genetic mutations must
occur in the zygote, or initial cell So, a creature very similar to a
chicken, which we could call a proto-chicken, would have mated with another proto-chicken and because of a small genetic
mutation, created the first chicken which grew in an egg So, the egg came first? Well, Team Chicken might argue
that this was simply a chicken growing inside of a proto-chicken egg however, no one mutation can
ever really constitute a new species even though we humans like to
classify all creatures into different groups and names this is based on how things currently
are and not how they were millions of years ago The process of evolution is so gradual that no one proto-chicken to chicken birth
could really be considered a new species at the time much like how dogs have come from wolves As humans began to interact
with and domesticate wolves, There was no one single point
where a wolf gave birth to a dog But rather, as particular traits
came about from selective pressures such as choosing wolves who are not afraid of humans or ones that were less aggressive over many generations we can
see big genetic and behavioural trait differences So where does this leave us? We're left with two scenarios: Some early egg laying species
gradually lead to the creation of the proto-chicken which laid proto-chicken eggs In one of these eggs, there was a mutation
causing a slight change and selective advantage and this was ultimately the first
chicken which then went on to lay chicken eggs In this case, the chicken technically came first Or we have a proto-chicken
which gave birth to a chicken inside of what we would classify as a chicken egg and, as such, the egg came first Which brings us back to the nomenclature
in question of what is a chicken egg? which is a fairly meaningless question but, at the end of the day, what we can all agree on is that regardless of whether it
was a chicken egg or a proto-chicken egg the first true chicken came from an egg The egg came first. Got a burning question you want answered? Ask it in the comments or on Facebook and Twitter and subscribe for more weekly science videos
About
We publish the transcription of a YouTube video. This is useful for: search, language learning.