Evolution Themes
for MdO Bluff Walk
© Bob Field
2005
Evolution of the Montana de Oro Bluff: The rugged beauty of the evolving coast reveals the powers of the
sea, sky, land, and life itself. Seasonal change and tides may be discussed.
Rain cancels. Meet at Bluff Trailhead, 200 yards south of Visitor Center at
Montana de Oro State Park. (*M) 3 mi., 3 hr.
Introduction
The topic is the physical and biological evolution of the Montana de Oro
bluff.
The theme is that everything you see from the MdO bluff has
a natural history; that is, everything changes over time.
The MdO Bluff is a special place because of its intrinsic
beauty, the result of the meeting of sea, sky, and land. We will walk a mile
along the bluff and stop to examine the graceful peaks, marine terraces, rugged
bluffs, speckled and layered sedimentary rocks, powerful crashing waves, the
light and color of the sky, and explore the interactions and relationships
among the five kingdoms of life – plant, animal, algae, fungus, and bacteria.
There is much to talk about and each walk may emphasize different factors
depending on the season and the visitors’ interests.
Subthemes and transitions
At each stop, we will discuss things we saw that were
influenced by the ocean, directly or indirectly, or by the Sun, atmosphere, or
solid Earth.
1. The structure, composition, origin, and evolution of the
sedimentary rocks you can see from the bluff reveal the forces of nature that
have deposited and then altered them, the ocean being one of the key
influences. The rocks came from the erosion of continental igneous rock that
came from the depths of the Earth. Much of the sediment came from the remains
of plankton that extracted silica from seawater.
2. The Sun influences the ocean, the atmosphere, and the
land in many ways; it is the energy source for winds, waves, tides, air and
water temperature, and the web of life. Over billions of years, changes in the
Sun’s output can be extremely important.
3. The atmosphere influences the ocean and the land and yet
life itself has altered the atmosphere and has affected climate and living
conditions and the course of evolution.
Over billions of years, changes in the composition of the atmosphere
have proven disastrous for some forms of life and beneficial to others.
4. The flowering plants on the bluff evolved from algae
with help from bacteria (fixing nitrogen), fungi (phosphorus), and animals
(insect, bird, or bat pollinators). Co-evolution, cooperation, competition, and
reproductive strategies are all factors in the ecosystem that includes all five
living kingdoms. Chance mutations of DNA imbued the descendants of green algae
to evolve into multicellular, differentiated, vascular plants with the ability
to form leaves and to form and disperse seeds through the production of flowers
and fruits. Changing conditions favored the descendants with certain traits by
means of natural selection.
5. Visitor options: The appearance and behavior of plants
and animals vary with daily and seasonal changes in the environment including
tides and weather as a result of natural selection. For more details see a
typical walk description. For more
information on my Global Evolution Education Project, see GEEP
or return to my home page.
Conclusions
Everything
evolves; everything changes over time - the sea, sky, land, and life itself.
Everything
you see is highly interactive and literally closely related.
It is the
role of science to provide plausible natural explanations for natural
phenomena.
How do
things change? When energy flows, complexity grows.