Transcript File

Dayton Chow
Keegan Friesen
Kyle Flavin
Nick Kruiper
Ancestors
Hesperornis (Lived
around 78-84 million
years ago in the
Cretaceous Period)
The scientific name for birds in general is Aves. The
scientific name for the modern day birds is
Ornithothoraces. Theropods (carnivorous creatures
such as: velociraptor or Tyrannosaurs rex) are widely
considered by scientists as the true ancestors of birds.
Archaeopteryx (Lived around 150 million
years ago in the Jurassic period)
Ancestors (Continued)
Liaoningornis (Lived around 125 million
years ago in the Early Cretaceous period)
Larry Bird (Still alive today
but has lost his ability to fly)
Musculoskeletal Evolution
Birds originally evolved from raptors and walked on all fours. overtime
their body's became slimmer and claws became smaller eventually they
started walking on only 2 legs and losing strength in the arms and
gaining it in there legs, this made them faster and more agile. much later
there arms started growing in an upwards fashion and forming a web like
skin flap underneath the arm, the wings were still not big enough for full
flight but biologists resulted that they used the smaller wing to slightly
glide over the ground for increased speed. overtime birds evolved with
larger wings with feathers attached and even slimmer body's giving them
the ability for full flight as well as ground movement.
Agents of Evolution
Genetic drift took affect on birds when resources
were depleted and predators became stronger in the
area. the birds would simply fly to the new
environment where they would thrive. the new
environment would work with and against there
current state, depending on how easy it was to obtain
food, the predators they faced and the surrounding
agriculture. certain genes would be selected to over a
long period of time create the most fit animal to
survive the new environment. The same cycle would
occur when new resources or other predators would
needed or evolve.
The environment is a big reason why birds begin to mutate and
change. If a natural disaster occurs; birds, like any animal have to
adapt. For example, birds could survive a volcano explosion if they
can fly over the ash or stay in the air for a long time until they can
find a new area. If there is a high flood, birds that can fly higher
would have a better chance of surviving and finding an area to rest,
thus making them more likely to survive and send their genes to
offspring. If a large storm were to arise it might force a population
of birds to flee their habitats in order to survive. They would be
forced to adapt. For example if they migrated to an are with a colder
climate and the only source of food was worms in the ground their
body's would have to evolve to suit their environment. By growing a
longer beak to eat worms underground and grow longer thicker
feathers to stay warm in the cold climate.
Environmental/Cultural Changes (continued)
There is a vast number of bird species and sub-species throughout the world, some
have similar characteristics, (appearance, vocals), while other species are completely
different. This is due to the development of birds in different regions.
Naturally, organisms develop and attain new traits very slowly over generations.
These traits help them survive better in their environment, giving them an edge over other
competition, therefore improving their chance of survival. At one point in time, when birds
first made their appearance on our planet, they all looked very similar. But as they began to
spread and separate, moving to different regions, changes start taking effect.
An easy way to explain how "birds change with the region" would be to refer to the
observations of Charles Darwin. The 19th centaury British scientist, Charles Darwin, observed
while spending time on the Galapagos Islands, that there were many different sub-species of
the Galapagos Finch. They all had similar looks, but the beak of finches on one island,
differentiated from the other. The reason for this was overtime a population of finches moved
to the Galapagos, and as they travelled to different islands there was different food sources.
Each species gained different traits to help them survive in their conditions. A finch who eats
insects has a shorter beak, while one who drinks from a cactus has a longer beak.
This motion of evolution is known as Darwin's theory of Natural Selection. Natural
Selection doesn't just affect one species of birds. It affects them all. Compare a penguin to a
owl. Then compare a eagle with an ostrich. What are the differences? What are the
similarities?
The similarities of all birds, no matter where they are in the world, are the traits
that all birds have, and are similar even if they provide different functions. Examples would be
the wings of hawk, versus the wings of a hummingbird. They are similar, but slightly different,
though internally, the structure of the wings are similar. Feathers, and beaks are also used to
classify birds, and they also are traits that develop differently overtime.
http://blog.hmns.org/2010/05/flat-footed-reptiles-to-high-stepping-chickens