Yosemite National Park is known for its breathtaking scenery including waterfalls, giant sequoia trees, and iconic rock formations. It was established in 1890 and protects diverse plant and animal species. The park is home to over 400 species including American black bears, Sierra Nevada bighorn sheep, and bats. Rock types within the park include quartz diorite, volcanic rocks from the Cenozoic era, conglomerate sedimentary rocks, and Half Dome displays the geological principle of crosscutting relationships as intrusions cut through older rock layers.

1. YOSEMITE NATIONAL PARK By Kelsey Darrin
Gel 103
I live an
hour away
from here!


2. INTRODUCTION: WHAT IS
YOSEMITE?/ HISTORY
Yosemite is a National Park within the Sierra Nevada mountain
range, it is known for it’s breathtaking scenery, ancient
Sequoia trees, astounding waterfalls, and iconic vista points:
Bridalveil falls, El Capitan, and Half Dome.
 Before being coalited into a park, Native Americans had
settled into Yosemite valley throughout the early 1800’s until
the gold rush of 1864 brought an abundant amount of miners
into the area. In 1864, conservationists convinced President
Abraham Lincoln to declare the area in a public trust fund of
California, this was the first time the U.S government had
preserved land for the enjoyment of others.
No one took charge until a environmentalist by the name of
John Muir had noticed that the land had been overrun by sheep
grazing due to a lack of govt help, so him and Robert
Underwood Johnson, a fellow collogue, lobbied for something
to be done, so on October 1st, 1890, Congress sanctioned off
1,500 sq. miles of land which became Yosemite and was the
third National Park to ever be created in the U.S.
Muir w/ President
Roosevelt on a
overhanging rock
(1903)

3. ALL DIFFERENT KINDS OF
CREATURES
Yosemite is home to a copious amount of animals including 90
mammal, 262 bird, 22 reptile, 11 amphibian, and many other
species which total in over 400 altogether, that make the area so
diverse, along with being one of the reasons why it’s ecosystem
thrives so well!
It is said that predators are extremely attracted to the park and
depending on the area between the forest and meadow, one is
able to find a large array of organisms scouring around, smaller
animals like it as well for it’s free roaming ranges and overall
protection for the outside world, many are known to be at higher
elevations.
The park contains 40 species that hold a special title under the
California endangered species legislation, recently it was
revealed that the Grizzly Bear, California red-legged frog, and
foothill yellow-legged frog had been added as well.
Some of the most populated and well known animals within the
land are the American Black Bear, the Sierra Nevada Big Horn
Sheep, and the Big Brown Bat.

4. THE AMERICAN BLACK BEAR
It is believed that bears’, including the American Black Bear, ancestry reaches all
the way back to 30 million years or so to, “…a family of small mammals known as
the Miacids (Miacidae). Some of the canine species resembled bears, and we refer
to them as bear dogs or Amphicyonidae. The size and appearance of the bear dog
varied from small and dog-like to big and bear-like…The family of real bears can
ultimately be traced back to the oldest genus, the Ursavus, which was roughly the
size of a sheepdog and had evolved from a canine ancestor” (Bears p.2).
The bear specie can be broken down into three subspecies, “…the giant panda
(Ailuropodinae), the spectacled bear (Tremarctinae), and the real bears (Ursinae).
The family of Ursinae consists of six different species, all of which have similar
external characteristics like strong claws and a robust body” (Bears p.3).
 Many scientists believe that multiple bear species, like the polar and brown bear,
had hybridized while evolving, causing multiple similar characteristics among
several bear families, some of these traits include increased strength, a larger
size, along with more advanced hunting skills such as climbing and such.
Fossils of this creature have been indeed found by paleontologists, but have a
hard time determining exactly what era they come from, some say they date back
to the Paleocene and Eocene epochs, but this is mostly for Miacid fossils.

5. EVOLUTION OF THE BLACK BEAR

6. AMERICAN BLACK BEAR FOSSIL
Now Then (Fossil of Prehistoric
Relative)

7. THE WESTERN FENCE LIZARD
(SCELOPORUS OCCIDENTALIS)
Another specie that is constantly seen throughout the National Park is the Western Fence
Lizard (aka the blue bellied lizard) and evolutionary wise is believed to have been around for
millions of years, at one time (during the Carboniferous Period) reptiles had dominated the
planet, but due to a mass extinction in the Jurassic Era, it had dwindled down to only 6,000
reptilian species that survived.
This creature is believed to be part of the Phrynosomatidae family and, “Evidence suggests
the family originated in one unknown area and spread with continental drift. Several genus
and species evolved from this family due to the isolation of phenotypes and challenges of
climate and predation. These genus are further differentiated by morphological
characteristics” (Bailey p.9).
One of these characteristics that is well-known and have scientists wondering is how they
evolved the trait of thermoregulatory behavior, a study had been done which observed the
relationship between this occurrence, temperature of their environment, and their body
temperature once they are born. It had been found that, “…significant variation in body
temperature was associated with family membership, suggesting that thermal physiology
has a genetic basis. Moreover, growth rate was correlated with body temperature among
families in each population suggesting a genetic correlation underlies the phenotypic
correlations. Thus, genetically based variation in thermal physiology contributes to
differences in growth rate among individuals within a population as well as to differences

8. EVOLUTION OF THE WESTERN
FENCE LIZARD

9. SCELOPORUS OCCIDENTALIS
FOSSIL
Now
Fossils of this creature have been found
in Western Oregon and other portions of
North America, some dating back to
their prehistoric roots, the picture below
is an archaic example.

10. THE CALIFORNIA POPPY
(ESCHSCHOLZIA CALIFORNICA)
Along with many types of creatures that roam the park, there is
beautiful vegetation that surrounds the area, along with a large array
of wildflowers, like the California Poppy that grazes the hill sides.
Their ancestor is also not well known, but are seen by professionals
as extremely archaic and many feel that they belong to the subclass
Magnoliiade, it is said that plants within this group are, “…extremely
heterobathmiid, that is, they have a very disharmonious combination
of both primitive and derived characters… the magnoliid families
evolved in various directions, but they most likely all evolved from a
common ancestor but the relationships between the families is not
yet understood… the magnoliids today may only be remnants of a
large ancient group of flowering plants and because of this the
subclass Magnoliidae is a collection of ‘living fossils’… they close to
Ranunculales and Berberidales (especially to Hydrasidaeae and
Podophyllaceae) and Glaucidiales and share a common origin with
them (Burt p.3)
The California Poppy is classified as a Angiosperm which first
appeared in the Lower Cretaceous Period(125 million years ago), but
became more diverse in the Middle Cretaceous Period (100 million
years ago), they are known to branch off into other areas within the
family such as Euangiosperms and Eudicots, it then reaches
Ranunculales and finally into Papaveraceae, also known as the poppy
family. They are also known for pollenating quite well, as an
Kingdom: Plantae
Subkingdom: Tracheobion
ta
Division: Magnoliophyta
Class: Magnoliopsida
Subclass: Magnoliidae
Order: Papaverales
Family: Papaveraceae
Genus: Eschscholzia
Species: Eschscholzia
Californica

11. EVOLUTION OF THE CALIFORNIA
POPPY

12. TYPES OF ROCKS WITHIN
THE PARK
And where to find them

13. QUARTZ DIORITE
Along with the vast organisms within Yosemite, it’s geology
is just as interesting, Quartz Diorite, a prime example, is
classified as a igneous plutonic rock, but not technically
granitic, and are known to be composed of five minerals:
quartz, potassium feldspar, plagioclase feldspar, biotite, and
hornblende. They contain for the most part large portions of
quartz and feldspar, plutonic rocks had began to form during
the Cretaceous Period.
Characteristics: Grey to dark grey color, richer in sodium
and poorer in calcium, their surface is speckled, also have a
coarse grained texture, they have repeated intrusions along
with deep erosion due to once being formed deep beneath
the earth and being exposed to the surface.
How to identify it: When looking at the different rock
samples, I was able to identify a quartz diorite in the park
mainly to it’s texture, color, and the amount of trauma it had
been through (erosions).
Plutonic rock: a
body of intrusive
igneous rock that
is crystallized
from magma
slowly cooling
below the surface
of the Earth.
Quartz Diorite
on Half Dome

14. VOLCANIC ROCKS (CENOZOIC)
Along with the various types of rock formations within
Yosemite, there is an abundance of volcanic rocks that
populate the area, they can be classified as plutonic as
well, but depends on their contents. Most volcanic rocks
are composed of a array of minerals especially basalt, but
depends for it can either have basalt which means it has a
low level of silica and is similar to gabbro or a rhyolite
which has a high level of silica and is more similar to
granite. Examples of this found in the park are basalt
flows, latite tuff, and latite lava flows
Characteristics: A limited range of composition, contain
little to no quartz, tend to be more fine grained or glassy
with a small amount of visible minerals.
How to identify it: I was able to find this specific rock
because of it’s smoother textures, more shiny/ clearer
appearance, and it’s darker color, also the area I was in
was well known for having these kind of rock formations.
It is also known that most of the volcanic rocks within
the park are from the late Cenozoic era and were formed
by large amounts of lava from smaller eruptions and
known to be found in eastern Yosemite at the Mono

15. CONGLOMERATE (SEDIMENTARY)
A rock formation that I have seen multiple times all
over Yosemite and within the Sierra Nevada
Mountain range, but never knew the name of was
the conglomerate and is scattered all throughout
the area. They are composed of rounded clasts filled
in between with smaller particles or a molecular
glue that holds it all together and can contain many
different sediments such as quarts, limestone,
chert, along with many other kinds.
Characteristics: Have a more rough and course
grained surface, depending on the clasts, they can
have the same strength are concrete and be smooth
to touch, the clasts are very visible, most of these
variables depend on the size and materials it’s made
of.
How to identify it: Although the conglomerate rock
can take on many forms, I was able to identify it
within the park due to all the visible clasts I could
see like a kaleidoscope of different sediments. Also
because of it’s tendency to not break cleanly, was
another contributing factor that made it stand out
as well.

16. PRINCIPLE OF CROSSCUTTING
RELATIONSHIPS (HALF DOME)
The principle of crosscutting relationships states, “…that an igneous
intrusion or a fault must be younger than the rocks that it intrudes or
displaces” (Monroe, 419), the infamous half dome is this principle in
action.
The reason behind why is applies to this principle has to do with the
process in which it was created, when it was formed, intrusions of
magma molten rock had solidified underground and this happened
repeatedly, as other rock layers eroded away, it had revealed what we
see today.

17. ANGULAR UNCONFORMITY (THREE
BROTHERS ROCK)
An angular unconformity is
defined as, “…an erosional surface
on tilted or folded strata over
which younger strata were
deposited” (Monroe), it is safe to
say that Three Brothers Rock can
be considered this kind of
unconformity because how each of
the “brothers” are folded over the
next and so on, also given by it’s
texture, one can see that a great
deal of erosion had occurred here.

18. WORK CITED
Yosemite National Park established. (n.d.). Retrieved June 25, 2017, from
http://www.history.com/this-day-in-history/yosemite-national-park-established
Animals. (n.d.). Retrieved June 25, 2017, from https://www.nps.gov/yose/learn/nature/animals.htm
Bratpack, B. I. (n.d.). The evolution of bear species. Retrieved June 25, 2017, from
http://www.bearsinmind.org/Page/The-evolution-of-bear-species
Evolutionary history of bears: It's complicated. (2014, June 11). Retrieved June 25, 2017, from
https://www.sciencedaily.com/releases/2014/06/140611093447.htm
The Biogeography of Sceloporus occidentalis. (2001, November 28). Retrieved June 25, 2017, from
http://online.sfsu.edu/bholzman/courses/Fall01%20projects/lizzard.htm
Sinervo, B. (1990, June). Evolution of thermal physiology and growth rate between populations of the
western fence lizard (Sceloporus occidentalis). Retrieved June 25, 2017 ,
fromhttps://www.ncbi.nlm.nih.gov/pubmed/22160116
Burt, J. (n.d.). The Biogeography of California Poppy. Retrieved June 25, 2017, from
http://online.sfsu.edu/bholzman/courses/Fall02%20projects/calpoppy.html
Geology. (n.d.). Retrieved June 25, 2017, from https://www.nps.gov/yose/learn/nature/geology.htm
The Geologic Story of Yosemite National Park (1987) by N. King Huber. (n.d.). Retrieved June 25, 2017,
from http://www.yosemite.ca.us/library/geologic_story_of_yosemite/rocks.html
Conglomerate. (n.d.). Retrieved June 25, 2017, from http://geology.com/rocks/conglomerate.shtml
(n.d.). Retrieved June 25, 2017, from
https://flexiblelearning.auckland.ac.nz/rocks_minerals/rocks/conglomerate.html
How Half Dome Formed. (n.d.). Retrieved June 25, 2017, from
https://www.scenicwonders.com/blog/how-half-dome-formed