Teeth and positivity

Why are things as they are? Is it because they are good and beautiful, or is it because they are a bit useless?

When positivity ignores problems or threats to maintain a “positive” mood, of “positive” feelings, it becomes toxic positivity, a problem. It creates blind spots blocking out reality. The threats and problems remain undealt with, so fester and metastasise. The toxic positivity becomes harder and harder to maintain, taking energy away from dealing with real world problems.

Worthwhile positivity- I might call it “realistic positivity”- finds all that is beautiful or worthwhile in a situation. It values emotions which toxic positivity finds unwelcome- fear, anger, perplexity- because they give useful information, as well as energy to deal with problems.

I want to preserve my rear right wisdom tooth, despite much of it being lost to decay. Reptiles and sharks replace teeth which break. Why don’t mammals? My understanding was that during the long Mesozoic reign of the dinosaurs, mammal ancestors became tiny, stayed out of the way, and didn’t do much until the Chicxulub meteor killed the dinosaurs. Because they were so small, they only lived one or two years, so lost the need to regrow teeth. One set of baby teeth and one set of adult teeth sufficed.

Our ancestors lost an advantage because they were small and insignificant, was the idea.

Steve Brusatte, in The Rise and Reign of the Mammals, explains it differently. Mammal jaws can chew. They move side to side. Reptile jaws take bites and swallow. Mammal teeth grind food down, so the stomach acids work more efficiently on small chunks of food. Just the right amount of wear on the teeth produced flat panels with sharp edges (p70), working like scissor blades. But, teeth which chew need to fit together. Mammal ancestors sacrificed the ability to regrow teeth in order to be able to chew, so process food better.

He also describes the Lilliput effect, whereby smaller animals may be more likely to survive a mass extinction, having shorter generations so adapting more quickly to changing conditions, and being able to burrow so avoid temperature swings. That helped our ancestors survive Chicxulub, and the end-Permian mass extinction.

The book was published in 2022. It helps to have the most up-to-date understanding. It also explains that mammal colour vision is poor because our ancestors were nocturnal. This resulted in other senses being heightened. Human colour vision is better, with three colour receptors, though other animals may have four. I see better if I avoid a solipsistic understanding.

I had thought there were five mass extinctions, but plants have suffered only two.

In the mid-20th century, extinct synapsids (from which mammals came) were called mammals if they had a particular kind of joint in the jaw. This century, mammals are defined as those creatures descended from the common ancestor of all surviving mammals. Other lineages are called mammaliaforms, though they may have had hair and warm blood, even a dentary-squamosal joint in the jaw. I notice Brusatte does not mention mammary glands until the Jurassic period: they are so important in Western culture.

There is a risk Boris Johnson may return as PM, though in July 57 ministers resigned from his government to force him from office, after he trashed ethics in government with his lies and lawbreaking. I am tempted to return repeatedly to the Guardian website, to find the latest developments. I could, thereby, maintain a feeling of horror and outrage. It is reassuring to feel as others do. I experience a heady sense of the rightness of my feelings. It distracts me from my immediate circumstances and concerns. I am probably better, then, to keep informed without continually returning to a source of inebriation. If there were an election, common feelings would help with common endeavour. I can’t link that to positivity, but it does fit to my desire to make my understanding of the world best fit my objective needs, and the continual temptation not to.

The picture is FunkMonk’s life-restoration of Morganucodon, a late-Triassic early Jurassic creature. The animal was warm-blooded, furry, able to chew, and as its young had a toothless stage, possibly it lactated. Not being a descendent of a common ancestor, palaeontologists call it a mammaliaform rather than a mammal. As Brusatte says, “nature doesn’t put labels on things, people do”.

5 thoughts on “Teeth and positivity

  1. You have an uncanny ability to capture my attention with your segues. Here it is the biological world and the final sentence/quote from Steve Brusatte. Humanity’s love affair with the ‘naming of parts’ is also reflected in straight lines on maps that cut across traditional tribal lands, animal migration routes etc. All in the name of progress/control. Geological time seems to be inconceivable to many or inconvenient at best.

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    • Thank you. Words don’t fit reality. Is a virus “alive”? It reproduces, but does not metabolize. That’s a problem with the concept of “alive”, not with viruses. But, for most purposes “alive” is a useful concept. It’s just all human concepts have grey areas not clear lines.

      As things are going, the current mass extinction won’t take geological time. Just a century or two.

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  2. Perhaps it’s best to keep the news noise at arm’s length. Yes, it’s tempting to feel informed, but I wonder if the feeling of near constant ‘OMG’ – or WTAF, this decade 🤦‍♀️- is not doing us any favours. Can we influence the prospect of the criminal being selected?

    Perhaps like the mammaliaform, we can only look at certain events, look out for each other, and hope to miss the next climate disaster.

    Still, cheery thoughts, eh? 😉

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