The Big Steps of Evolution

We can show evolution taking small steps in the labs. But evidence for large evolutionary steps is unfortunately a bit rarer. This leads some non-experts to deny that small evolutionary steps can compound into large changes over time. So, it’s interesting to explore some of the important evolutionary milestones in the lab. One of those milestones is single celled organisms -> multicellular organisms. New Scientist is reporting that this step has been observed with Yeast in the lab.

Yeast clumps

Sure enough, within 60 days – about 350 generations – every one of their 10 culture lines had evolved a clumped, “snowflake” form. Crucially, the snowflakes formed not from unrelated cells banding together but from cells that remained connected to one another after division, so that all the cells in a snowflake were genetically identical relatives. This relatedness provides the conditions necessary for individual cells to cooperate for the good of the whole snowflake.

After a few hundred further generations of selection, the snowflakes also began to show a rudimentary division of labour.

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