Transcript for Science in Seconds - Lamarckian Evolution

Science in Seconds

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RUMOURS - Lamarckian Evolution

Rheanna Sand: Darwin gets all the glory,

but there is one evolutionary thinker making a comeback.

Jean Baptiste Lamarck had a theory that an animal could pass on to its offspring

traits it acquired through its lifetime,

but Lamarckian evolution was either ignored or ridiculed

for its violation of basic heredity principles.

Modern principles state that traits are passed on

through molecules of heredity, our DNA.

Things you learn during your lifetime do not get written in your DNA,

and do not get passed onto your offspring.

But Lamarck believed information gained in one's lifetime

could be transmitted biologically to the next generation.

A common example given is the giraffe's neck.

Lamarck figured as they were reaching for taller branches

their necks stretched. Then, when they had babies,

the babies were somehow endowed with this longer neck.

What an idiot, right?

Well, its true giraffe necks haven't evolved that way,

but acquired information can be passed to the next generation.

The information isn't encoded in DNA, but rather in molecules

that are involved in decoding the DNA message. Epigenetics, as it's called,

looks at how DNA is acted on by other molecules, and these molecules

can be different depending on the experiences of an individual.

For example, chickens with unpredictable food supplies seem to produce offspring

that are better capable of dealing with such unpredictability,

regardless of their genetic makeup.

In other words, organisms can learn from their environment

and cause changes to the offspring that help it to adapt.

It's a shame Lamarck died in obscurity and extreme poverty.

His story is just one more reason not to dismiss

the so-called idiots of science.

Go suck it, Darwin!

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