Exploring Evolution in the Museum

Explore five kingdoms of life and five billion years of natural history in a one hour guided tour of the museum exhibits and vistas. We will discuss tides and seasonal changes in four habitats: estuary, rocky shore, dunes, and woodlands. Meet in the rotunda of the Morro State Park Museum of Natural History. (*E) 0.1 mi., 1 hr.

The tour starts in the rotunda with a look outside at the estuary and walks through the museum and maybe ends on the balcony or in the auditorium in order to connect the forces of nature exhibits with exhibits of the four habitats:

1. Rocky shore - tidepool, surge channel, ocean side, tide face

2. Dunes - wind face, lee face, swale, under plants

3. Oak woodland - canopy, shady ground, sunny ground, trunk

4. Estuary - channel, mudflat, tidal flat, underwater

The view from the rotunda introduces the forces of nature which are then translated to the rotunda exhibit of the estuary and ties in to the exhibits in the back of the museum. As we examine the habitat exhibits we will examine some specimens and emphasize ecological and evolutionary processes. I will mention that the nature store has many informative and entertaining books including my favorite, Dr. Art’s Guide to Planet Earth. I will also entertain questions and comments for a half hour after the tour.

Introduction

The topic is the physical and biological evolution of the Central Coast. The theme is that everything you see in the museum exhibits and the museum vistas has a natural history; that is, everything changes over time.

The Central Coast is a special place because of its intrinsic beauty, the result of the meeting of sea, sky, and land. We will tour the museum 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 tour may emphasize different factors depending on the season and the visitors’ interests and my evolving understanding of nature.

Our local natural history illustrates how evolutionary processes work

As we tour, we will discuss things that were influenced by the ocean, directly or indirectly, or by the Sun, atmosphere, or solid Earth. The idea is to start with the concrete – what you actually see – and go to the abstract – what you don’t see.

1. Morro Rock has a different history than the sedimentary rocks and sand spit nearby. The tops of continents rise above sea level because their light colored and light-weight silica-rich rocks lost much of their heavy metals like iron and magnesium when they were molten. Elements like calcium, silicon, and aluminum originally came from the erosion of continental igneous rock that came from the depths of the Earth. Some minerals found in sedimentary rocks cycled through diatomaceous plankton that extracted silica from seawater. The structure, composition, origin, and evolution of sand, mud, and rocks reveal the forces of nature that have deposited and then altered them, the ocean being one of the key influences. One of the forces of nature is the lichen that grows on rocks, whose acids help break down rock and form soil. Did you know that lichens are a symbiotic combination of a decomposer (fungus) and a producer (either algae or cyanobacteria or both)?

2. Where did the water in the estuary come from? Where else do you find water? How does water interact with sunlight and with the heat radiated from the Earth’s surface? 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. Imagine air, water, rocks, bones, plants, and animals. What are they made out of? Which one has the smallest fraction of oxygen atoms? Composition influences structure, but structure determines function. 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. Where would you find the greatest mass of life? Where is the greatest diversity of life?

4. Chance mutations of DNA enabled some 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. Flowering plants evolved from algae with help from bacteria (fixing nitrogen), fungi (phosphorus and minerals from the soil), and animals (insect, bird, or bat pollinators). Many plants also rely on animals to spread seeds which are often contained in fruits that attract animals.

5. In addition to flowers and fruits, plants often produce substances that attract or repel animals including fragrances, flavors, and toxins. Many other organisms including single celled microbes produce toxins as well. The ability to absorb, reflect, or scatter light and color also influences the survivability of organisms encompassing photosynthesis (light collection for energy), sensing light sources and images (light collection for information), and alterations in an organism’s visibility (camouflage, warning colors, attractive displays).

6. Co-evolution, cooperation, competition, and reproductive strategies are all factors in the ecosystem that includes all five living kingdoms. Changing conditions and radiation into new environments favored descendants with certain traits acquired by means of natural selection. Off shore, there are peat beds, precursors to coal, typically formed from undecomposed woody plants that evolved before any decomposers could break down their strong carbon-based fibers.

7. Organisms rely on solar and/or geothermal energy sources and fluids and nutrients from the air, water, and land. The appearance and behavior of plants and animals are adaptations to daily and seasonal changes in the environment including tides and weather that evolved over millions of years by means of natural selection.

Discussion questions about natural systems

The natural history of planet Earth is the result of the interactions of eight natural systems: oceans, atmosphere, solid Earth, Sun, molecules, cells, organisms, and ecosystems. Typical guiding questions for science educational materials and programs are as follows:

1. What are natural systems made out of (composition and structure)?

2. How do natural systems work (material properties and interactions with energy)?

3. How do natural systems change over time (evolutionary processes)?

4. Where do natural systems come from (origin and/or formation from building blocks)?

5. What are the relationships between the parts of a natural system (interactions and ancestry)?

6. What are the relationships between natural systems (interactions and origins)?

7. How do natural systems become more complex over time (energy flow alters and combines simpler building blocks)?

Concluding messages

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.

Or to be more precise: When energy flows, (local) complexity (often) grows.

Variations of this program can be done in nearly any indoor or outdoor nature venue.

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