science

Banana slugs evolved from snails, and both are classified as Gastropoda. The slugs’ deterrent slime permitted them to almost completely abandon the protective but cumbersome shells carried by their snail ancestors. A few predators manage to eat banana slugs despite their defensive production of copious mucus, but the process is disgusting to watch. Some potential […]

Our bedrock consists of an exceptional diversity of rocks spanning over 100 million years of history. The diversity is due to our location at the convergent boundary between continental and oceanic plates. To enjoy this diversity you should visit Trinidad Beach, where the "Franciscan" subduction complex consists of a mix of rocks from both plates. […]

A human female is diploid, having paired maternal and paternal chromosomes. She is born with over a million haploid eggs with unpaired chromosomes. Each egg has the potential of being fertilized by a haploid sperm.  A fern’s life cycle is more complex. It alternates generations between a large diploid “sporophyte” plant that produces haploid spores and a small haploid “gametophyte” plant, grown […]

I had intended to write about ferns and their shady lives, but realized that I should first review the fundamentals of reproduction. The diagram shows the basic concepts, under the assumption that each parent provided one chromosome to form a diploid cell with a pair of chromosomes. (Further simplification is my equating cells with nuclei.) […]

Geologic time was involved in my previous articles on earthquakes, marine terraces, photosynthesis and changing climates. I contend that grasping the immensity of geologic time is a prerequisite to a real understanding of our planet and its life. Twenty thousand years ago, Canada was buried under three kilometers of ice and sea level was 140 […]

Yes, interest in fungi is expanding. However, few of us are aware of their strange life cycles and the valuable contributions they make to the health of our forests and fields. Begin with one spore produced by a typical mushroom. It is haploid, meaning it has only one set of chromosomes (like a sperm). The […]

An example of a marine terrace is the surface on which McKinleyville is built. At some time in the past, roughly 85,000 years ago, this terrace was barely below sea level, and that is why it is flat. Land above sea level was eroded down by rain and surf, while submerged land was built up […]

Fossil fuel combustion has already increased the concentration of carbon dioxide in the atmosphere by 36 percent over pre-industrial levels, from 280 ppm to 380 ppm. This contributes to global warming because CO2, despite its low concentration, effectively absorbs outgoing thermal infrared radiation. (Other greenhouse gases are water vapor, methane and ozone). The correlation between […]

Our comfortable levels of atmospheric oxygen (O2) and carbon dioxide (CO2 ) are attributable to photosynthesis: H2O + CO2 = CH2O + O2. It is thus reasonable to assume that forests are needed to preserve the oxygen we breathe. But that is a common misconception. A mature redwood or Amazon forest busily recycles its products, […]

Among all the fantastic products of three billion years of evolution, such as intricately constructed ears, eyes and skeletons, the most amazing exists within primitive anemones, corals and jellyfish. The stickiness you feel when touching anemones in local tide-pools is a consequence of thousands of microscopic harpoons launched into your skin. Each launching mechanism is […]

PG&E is seeking permits to investigate the feasibility of producing energy from waves off Humboldt Bay. The potential is high off our coast because of our winter storms and summer winds. Waves approaching shallow water begin to break and lose energy, so most schemes target waves in water deeper than the “wave base” (about half […]

If you watch the red sun just before it disappears below the sea’s horizon you may see a flash of green. Gene Callahan, a local builder of fine homes, tells me that a red road flare will turn green if stared at long enough. These phenomena are actually quite different. Gene’s green is a result […]