Some of the Things that Molecules Do
Study Guide for Episode 2
Episode 2: Some of the Things that Molecules Do
People
• Charles Darwin, who originated the idea of evolution by natural selection acting upon natural variation, is the main source of the ideas in this chapter. Tyson's script is very precisely worded to be in keeping with accepted evolutionary principles. As the episode develops, he lapses into common simplified shortcuts in language, which might help you to recognize what such shortcuts can obscure about accurate explanations. These shortcuts are part of common parlance among biologists.
It has been said that nothing in biology makes sense except in the light of Darwinian evolution.
Ideas
• Comparing artificial selection with evolution by natural selection.
• Contingencies: rare, unlikely events such as the asteroid that made human history possible.
Updates
• We know much more today about how intimately our lives are entwined with bacteria. A healthy human body probably contains more bacterial cells than human cells. More HERE.
• More than 99.9% of all species that ever lived are now extinct. And it's NOT our fault! It's always been true. The odds of any new species surviving are practically zero.
See THIS IMAGE of an evolutionary tree that shows many extinctions as well as living species. Living species are represented by branches that reach the top surface, and many of them are labeled. Extinctions are represented by branches that end before reading the surface, with a few major extinctions label at the top. Only a small fraction of the extinctions are shown. If all extinctions were shown, the diagram would be solid black -- it's a jungle out there.
• Consumer DNA testing. What might you learn? How much does it cost? Click HERE.
• If you own a mixed-breed dog (good for you!), you can find out what breeds are represented in its genes. You might even learn about breed-related health conditions that might help your vet anticipate health problems. The operative words are "might". Click HERE.
• How dog-breed testing grew out of cancer research. Click HERE for abstract. (Click "View Full Text" for full technical paper, but subscription to Science might be required.)
Readings
• Extinction Event, at Wikipedia. Links within the article take you to more information about the extent and cause of all major extinction events. Tyson visits the Halls of Extinction, mentioning the "five great catastrophes" in Earth's history. He talks mostly about the Permian.
• When was the Permian period? For much (too much?) more information, see Geologic Time Scale at Wikipedia.
• Poems: Robert Frose, "On a Bird Singing in Its Sleep" and "Design".
• Essay: Robert Frost: Poetry After Darwin.
Advanced Stuff
• If you have substantial background in molecular biology and genetics, try this tutorial on how to compare proteins or genes and make phylogenetic trees:
Bioinformatics for Beginners
People
• Charles Darwin, who originated the idea of evolution by natural selection acting upon natural variation, is the main source of the ideas in this chapter. Tyson's script is very precisely worded to be in keeping with accepted evolutionary principles. As the episode develops, he lapses into common simplified shortcuts in language, which might help you to recognize what such shortcuts can obscure about accurate explanations. These shortcuts are part of common parlance among biologists.
It has been said that nothing in biology makes sense except in the light of Darwinian evolution.
Ideas
• Comparing artificial selection with evolution by natural selection.
• Contingencies: rare, unlikely events such as the asteroid that made human history possible.
Updates
• We know much more today about how intimately our lives are entwined with bacteria. A healthy human body probably contains more bacterial cells than human cells. More HERE.
• More than 99.9% of all species that ever lived are now extinct. And it's NOT our fault! It's always been true. The odds of any new species surviving are practically zero.
See THIS IMAGE of an evolutionary tree that shows many extinctions as well as living species. Living species are represented by branches that reach the top surface, and many of them are labeled. Extinctions are represented by branches that end before reading the surface, with a few major extinctions label at the top. Only a small fraction of the extinctions are shown. If all extinctions were shown, the diagram would be solid black -- it's a jungle out there.
• Consumer DNA testing. What might you learn? How much does it cost? Click HERE.
• If you own a mixed-breed dog (good for you!), you can find out what breeds are represented in its genes. You might even learn about breed-related health conditions that might help your vet anticipate health problems. The operative words are "might". Click HERE.
• How dog-breed testing grew out of cancer research. Click HERE for abstract. (Click "View Full Text" for full technical paper, but subscription to Science might be required.)
Readings
• Extinction Event, at Wikipedia. Links within the article take you to more information about the extent and cause of all major extinction events. Tyson visits the Halls of Extinction, mentioning the "five great catastrophes" in Earth's history. He talks mostly about the Permian.
• When was the Permian period? For much (too much?) more information, see Geologic Time Scale at Wikipedia.
• Poems: Robert Frose, "On a Bird Singing in Its Sleep" and "Design".
• Essay: Robert Frost: Poetry After Darwin.
Advanced Stuff
• If you have substantial background in molecular biology and genetics, try this tutorial on how to compare proteins or genes and make phylogenetic trees:
Bioinformatics for Beginners
