From Single-Celled to Multicellular Organisms in Just Six Months

Life is amazingly complex. Our bodies have eyes, brains, skin and tons of different types of specialized cells. There is absolutely no possible way that this amazing complexity could possibly have sprouted from single-celled organisms that just float around on their own. At least, that’s what creationists would have you believe. Apparently, they don’t believe the evidence indicating that multicellular organisms evolved from single-celled ancestors at least 25 times in Earth’s history.

Well then maybe they’ll believe it now that it has been demonstrated in a laboratory.

William Ratcliff from the University of Minnesota has demonstrated one way that multicellular organisms could evolve and he’s done it in just 60 days. In the new study published in the Proceedings of the National Academy of Sciences, Ratcliff begins with single-celled yeast called Saccharomyces cerevisiae and used gravity as the selective pressure to breed a new organism.

By themselves, yeast take a while to sink in water. But when clumped together – which yeast often do – they sink more quickly. So Ratcliff selected those that sank faster and tended to clump together and allowed them to breed new generations. After many rounds of new generations, the yeast began forming multicellular organisms.

What this means is that the cells did not just form a big clump of genetically distinct organisms. The cells in the new organisms were genetically identical – like those in your own skin – and formed a type of “snowflake” that slowly grew larger. What’s more, once these new snowflakes reached a certain size, they split apart into a smaller, daughter snowflake.

They procreated.

This happened because even in such a short time span, the cells began forming a rudimentary separation of labor. Like we have cells specialized for seeing, hearing, thinking and feeling, the snowflakes grew cells for reproduction. Once the organism reached a certain size, these cells purposefully died off in order to allow the new daughter flake to be separated from the larger whole. This mirrors a similar division seen in today’s more complex multicellular organisms where body cells die off every generation and germline cells (sperm and eggs) carry over into the next generation.

The results aren’t really that surprising. I mean, science already knew that this could happen and has happened many times. What’s shocking is the speed at which the progression took place. If heavy pressures could induce multicellularity in just two months, image what it could do over billions of years.

Or just look around you.


About bigkingken

A science writer dedicated to proving that the Big Ten - or the Committee on Institutional Cooperation, if you will - is more than athletics.
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