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.

Advertisements

Mostly, health claims in newspapers are bunk

Ben Goldacre (of Bad Science fame) and some colleagues have done some research into the reliability of health claims made in UK newspapers. The results suggest that newspapers have a lot of misleading information.

The vast majority of these claims were only supported by evidence categorised as “insufficient” (62% under the WCRF system). After that, 10% were “possible”, 12% were “probable”, and in only 15% was the evidence “convincing”. Fewer low quality claims (“insufficient” or “possible”) were made in broadsheet newspapers, but there wasn’t much in it.

Ben describes his research here.

How to predict the future

Wouldn’t it be nice to know what the weather is going to be like next week? What the stock market is going to be like tomorrow? What the housing market is going to be like over the next decade?

This BBC Radio 4 episode of discusses how accurate experts are at making predictions. It turns out they are not any more accurate than random chance. It may seem like they get a lot of things right, but if we don’t keep careful records, we may be selectively remembering their hits better than their misses.

So, what can make an expert better at predicting?

According to experiments, a few of the experts have modest predictive abilities. These experts were characterized by a willingness to be honest about their uncertainties, using numerical, probabilistic terms, and getting regular, precise feedback.

There does seem to be a different kind of style of thinking in some experts which is much more cautious…These people tend to be a lot better at making predictions.

Don’t trust an expert who is certain about the future. They tend to be only as good as chance and they are unlikely to improve as the feedback comes in.