Monday, March 6, 2017

The Political Page, T+45 -- March 6, 2017

The clamor for Attorney General Sessions to resign seems to have gone to the back burner; replaced by the Obama wiretaps, real and imagined.

GM: cuts a product line at Lansing, MI. Cuts 1,100 jobs in Michigan; creates 800 jobs in Tennessee.

For Pocahontas in Boston, on charter schools, a screenshot from The Boston Globe. I think this is called "voting with your feet"; Betsy DeVos, take a bow:

Voting with their feet: there are a number of stories out there today that suggests the Canadians are "struggling" with surging numbers of refugees fleeing from the US. I honestly did not know that many Hollywood cupcakes were following through on their promises to leave the US if Ivanka Donald was elected president. But there you have it. I also don't know why the Canadians are "struggling" with all the refugees: a) it was predicted; and, b) Justin Trudeau welcomed them with open arms. It looks like the refugees might be getting a cold reception in more ways than just the weather.

The Vital Question: Energy, Evolution, and the Origins of Complex Life
Nick Lane
c. 2015

The lexicon of biology is incredibly difficult for me; I need to keep reading and re-reading to remember it.

A huge problem is that once words get into the lexicon of biology (or any discipline, I suppose) they come to mean different things for different people over time, or they are used inappropriately or without "precision."

 Everyone who graduated from high school after 1969 now knows the Lynn Margulis hypothesis, that "bacteria" "ingesting" mitochondria led to eukaryotes.

Where we are today, at least as I understand it from Nick Lane.

Carl Woese in 1977 studying ribosomal genetics identified three domains of life: archaea, bacteria, and eukaryotes.

Archaea and bacteria appear morphologically very similar, neither having a nucleus, therefore both being prokaryotes but their chemistry / genetics is very different.

Eukaryotes, the third domain have nuclei and dozens of traits that characterize "complex" life and are not found in prokaryote (bacteria or archaea).

Break, break.

That's the "evolutionary niches": prokaryotes (archaea and bacteria) and eukaryotes.

Now, we move to "ecological niches."

Prokaryotes and eukaryotes each occupy distinctive ecological niches.

At some point during the evolution of life, it appears that a "subset" of very simple, single-celled eukaryotes "filled" in an ecological niche that bacteria/archaea (prokaryotes) failed, for some reason, to occupy (I'll call it the "third" ecological niche). These simple, single-celled eukaryotes now go by the name of "archezoa" -- which, of course, makes things very, very confusing. But archezoa ("zoa" for "animal"; like "protozoa" - "first animal" to describe motile organisms like amoeba) are clearly eukaryotes. At one time, the archezoa were mistakenly considered the "missing links" between bacteria and the more complex eukaryotic cells.

Nick Lane argues that the origin of complex life depended on the acquisition of mitochondria. Said another way: mitochondria triggered complex life. Said yet another way, the mitochondrial-acquisition event was the origin of complex life.

The gap between bacteria and complex life is huge. Nick Lane will explore what "drove" complex life.

Nick Lane also asks the question why archezoa and not bacteria filled that "third" ecological niche. He will argue that something "constrained" bacteria from being able to fill that niche.

Along the way, he will discuss the relationship between eukarotes and archezoa.

Other definitions:
protists: single-celled eukaryotes, some of which can be very complex
protozoa: a subset of protists, "first animals," such as amoeba
bacteria: generally used to refer to both "bacteria" and "archaea" but the latter represent two of three domains (the third domain being eukaryotes)

But most critical: do not confuse archaea and archezoa.
archaea look a lot like bacteria, but differ genetically and biochemically; discovered by Carl Woese to be the third domain; like bacteria, archaea are prokaryotes (no nucleus; no complex life traits)
archezoa may look a lot like bacteria but they are true eukaryotes (having a nucleus and similar complex traits as all eukarotes.

Finally, the third domain, eukaryotes were divided into five (5) supergroups by Carl Woese. Archezoa are found in all supergroups. I believe the supergroups are genetically determined.

I have to go through this over and over so I can keep up with Arianna and Olivia.

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