evolution

904

Microscopic, clam-shaped creature
Another microscopic creature from our desert puddles. One of its relatives played a very interesting role in World War II. What is it?

905

Tiny, scale-like objects
Another microscopic photo. These tiny structures define an entire group of organisms, even giving them their name. What are they from?

918

Black widow spider and baby spiders
My Black Widow Spider's egg case hatched, releasing hundreds of tiny babies. While prey animals tend to have lots of offspring, most predators tend to have relatively few offspring. Why do spiders have so many babies?

923

Pinyon Jays at feeder
Huge flocks of Pinyon Jays are visiting our feeders this week to get ready for winter. They are picking out the sunflower seeds and swallowing them whole. Why?

924

Trees with yellow leaves
Although we have had several freezes, the leaves here are just starting to change. Every year, the leaves start changing colors in the North first, and then the color change spreads South. This is not due to the temperature. What causes it?

929

Baby spiders
Another egg case from my Black Widow spider just hatched. Notice that the babies are brown and white, instead of the characteristic shiny black with red markings. Why?

936

Onion cells
These are onion cells, photographed through my microscope at 40X. Why do onions make your eyes water when you cut them?

949

leaves in snow
The mustard plants in my garden are still green, in spite of sub zero temperatures and snow. How do they survive when most of the other plants have not?

956

hawk droppings
The hawk who roosts on our cliff has left plenty of evidence. Why are bird droppings usually white?

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