Why did life take so long to become multicellular?

[Chronos]

Even though we primarily use dextral sugars, I’m pretty sure that we can still digest and make at least some use of sinistral sugars.

[doubleminus]

@Chronos

Even though we primarily use dextral sugars, I’m pretty sure that we can still digest and make at least some use of sinistral sugars.

Well, they are sweet, and have no calories…but are too expensive to make and we’re not sure about side effects. From the fascinating book Symmetry and the Beautiful Universe by Nobel laureate Leon Lederman:

Complex living organisms on Earth all evolved from simple primordial
organisms. One compelling indication of this is associated with the
handedness of the molecules out of which we are built. We share particular
stereoisomers with all other species. When the primordial organisms
formed, certain random events happened, causing one of them to use, for
example, a levo-molecule for a particular function. The choice was
random, like the flip of a coin, the incorporation by chance of a given
stereoisomer into the organism happened by mutation. But once the
choice was made, all of the subsequent progeny of this single organism
inherited the same stereoisomer for the particular function.

…

For example, most types of sugar molecules found in organisms on
Earth are the right-handed kind, or dextro-sugars, though the mirror
image levo-sugars can be produced commercially or in the laboratory.
The digestive enzymes in our stomachs, however, evolved to digest only
the dextro-sugars that we normally encounter on planet Earth-the mol-
ecules that come from the other living organisms that also evolved on
planet Earth. These dextro-enzymes do not chemically interact (in the
same way) with the levo-sugars, so the levo-sugars are not digested.
However, the nerves in our taste buds savor the levo-sugars as though
they were dextro-sugars.

[Ludovic]

@Chronos

sinistral sugars.

Band name!

[Stranger_On_A_Train]

@doubleminus

Random is as good an answer as any, since the probability is half. But this is not the question. The question is why in the 4.5Gy since earth formation there has not been any new life creation with the opposite direction. Such life would not be competing with the established life since D-aminoacids and L-sugars are unusable by known form of current and past life, this protecting them from destruction.

The best answer to that is irrespective of not being in direct competition for amino acids of different chiralities, the existing life used up other natural resources. Once one form of life has taken hold and differentiated, it is explicable that no other nascent life would be able to compete purely on the basis of differential efficacy of reproductive and metabolic processes. It will be interesting to see if the predominance of left-handed chirality holds (among other characteristics of life as we know it) if we find independently evolved life on the Jovian or Saturnian moons.

Stranger

[Broomstick]

@Terminus_Est

Article says that the creature is still a metazoan, i.e., an animal. It’s only secondarily anaerobic, having evolved from ancestors that had mitochondria.

But it doesn’t have mitochondria - which means multi-cellular life without oxygen is possible. On another planet it might arise differently, but the point is that it is possible. Just as we have proof that life can live at the temperature of boiling water, or in sub-freezing liquid, or in much lower or higher pressures that we ourselves experience.

[billfish678]

Not based upon any real science…but…you have two jumps here…cellular life…one big assed jump…then multicellular life…ANOTHER big assed jump…not to hard to imagine the second jump is harder than the first…and for that matter “we” may have gotten lucky time wise on the first jump…or a bit unlucky on the time taken for the second jump for that matter.