ابسط شرح لنظرية التطوّر - Evolution for dummies


Uploaded by 3MEphysics on 15.07.2012

Transcript:
(Evolution)
I've heared so many debates about it
but what annoys me is that the theory of evolution is not a debate it's a fact
evolution is responsible for the complexity and difference and consistency of the life around us
and it gave us all the beauty around us to marvel at
despite it made all the animals different from each other, it shows us how similar we are
in this video, I will try to explain evolution as simple as possible
in my opinion, there are two kinds of people first kind : are people who are ecxited about the power and simplisity of evolution
the second kind : are people who .... just don't understand it
but before we start talking about evolution we have to correct some of the wrong concepts about it
some people say it's against religion and the answer is no...
just no..
other people say that it's "just" a theory, and that means that they don't know the meaning of the word theory
in everyday-speech, people use the colloquial definition to mean "idea", "conjecture", "hypothesis", "guess", or "assumption".
fact of the matter is, the scientific definition is none of them.
In a scientific context, the word “theory” means, “An explanation of a natural phenomenon, strongly supported by evidence.”
A lot of people believe that scientists have a theory,if their theory is proven, it becomes a law.
That is not the case. Theories do not become laws and laws do not become theories
laws describe phenomena and theories explain phenomena
"Law : the apple falls towards the ground"
"Theory: the apple falls towards the ground BECAUSE of gravity"
and if you still think that theories are wrong ... go jump out of the window ... because gravity is just a theory
"Gravity is JUST a theory"
go jump !!
another myth about evolution is that people thinks that some sort of animals (a horse for example) wanted to eat from a long tree
so it started stretching its nick ... then poof! it became giraffes
but this isn't evolution ... this is mental retardation
Life on earth have started as a single cell which evolved the capacity to live in colonies , becomin simple multicellular organisms like sponges
which became early invertebrates which branched into vertebrates some of which which became fish
,then amphibians one of which (tiktaalik) is famously among the first to crawl onto dry land
where amphibians branched off into reptiles , which branched into birds and mammals, then to the animals we can observe today
some of these mammals lived on the trees
but some of them descended and learned to walk upright
in order to carry tools/food/young
of course these proto humans eventually became ..... you.
but that all still don't make any sense
I mean how a fish evolved and evolved till it became humans ? did it grow arms and legs suddenly ?
of course not ... that is the evolution of Pokémon .... we may discuss it in another video
to understand how evolution occurred .. let's take a simple example
tigers, cheetahs and cats, they have the same origin, and the members of an origin have different characteristics, just like humans
some of them are tall, others are short, some are fat, others .. are also short
etc.
the origin of tigers, cheetah and cats also had members' different characteristics
some had velocity, some had strength, and some had ... cuteness
the members which had velocity preferred to hunt gazelles, because they are (also) fast, and the don't require strength to be killed
and the members which had strength weren't fast enough to hunt gazelles, so they preferred to hunt large animals like cows and buffalos
But the cute members
had been domesticated by humans
so animals like cows, cats, dogs, and hamsters are existing because of humans
and they are not able to survive out of human societies
so without humans ... they wouldn't even exist
if we compared the tiger and cats thing with humans and apes
we'll find that some of them proceeded to establish civilizations and cultures
... and others decided to play and jump on trees
but what's the evidence for the evolution ?
the first evidence are the transitional fossils
they are fossils of animals that used to live before us ... that evolved
but let't just say that they are not connected with animals today
what is the other evidence ?
as we know who are the babies real parents by the DNA
we can also know our ancestors by the DNA
You know that humans and champs share 98,5% of the DNA
and human DNA also is similar to fift... I mean ... 75% of the DNA of rats
and it's also 50% similar to the DNA of ...
Fruite flies
the third evidence for evolution are the useless body parts
the SUBCLAVIUS MUSCLE for example
it's a small muscle stretching under the shoulder from the first rib to the collarbone
our ancestors used it to walk on four
(and that's also why you move your hands while you're walking)
some people have one of this muscle,
some have none, and a few have two.
If you want to know more useless body parts ... you can check the link below
It's from "discover" magazine, and it's peer-reviewed
that means that it was rievewed by specialists
"Did you know: 100% of people who drink water DIE ! "
and that was the theory of evolution
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