It's difficult for any evolutionary biologist
to understand some of the arguments against
evolution that are in the public domain.
I mean, the evidence for evolution is not
only overwhelming, but it drives everything
that we do.
Goldschmidt famously -- who is a famous geneticist
once said that nothing in biology can be understood
except in the light of evolution.
And that's true.
I think we wouldn't understand as much as
we do about the pathways that I described
without the evolutionary side of it that makes
it all real.
Especially in plants.
We can rewind the clock of recent evolution
by remaking a hybrid, for example, and then
seeing how it evolves in the laboratory or
in the field and compare that to what we know
happened even in recent history.
And so evolution is an experimentally tractable
topic.
I mean, it's very real.
One of the most famous branches in plant's
evolution is the difference between gymnosperms
and Angiosperms.
And let me explain what they are.
They're both seed plants so they have seeds,
but Angiosperms also have flowers, so whereas
gymnosperms have a different sort of reproductive
structure or cone.
So people will be very familiar with, for
example, with cones on pine trees, which are
gymnosperms and flowers on, you know, their
favorite garden plant.
The difference between gymnosperms and angiosperms
is very important in evolution because angiosperms
were able to somehow radiate into thousands
and thousands and thousands of species, whereas,
gymnosperms are rather narrow in their species.
Also, gymnosperms have very, very large genomes
that are largely a component of transposons.
Transposons are pieces of DNA that can move
around the genome.
And so they, they can move potentially and
cause genetic as well as epigenetic changes
without having to go through a sexual cross.
And most genomes are actually composed mostly
of transposons.
So, for example, the human genome is about
50 percent transposons and only about five
percent genes.
The maize genome is even more extreme, it's
about 80 percent transposons and only two
or three percent genes.
So the bulk of the genome is actually prepared,
if you like, for epigenetic change.
And this is the area that we work on the most
looking at the way in which transposon control,
and especially epigenetic transposon control,
has influenced the phenotype, the properties
of plants over the generations.
Darwin famously referred to the radiation
of angiosperms, the generation of thousands
of species, as an abominable mystery because
it didn't fit with his gradual change hypothesis
of evolution.
And we think that maybe some of the explanation
lies in this ability to control transposons.
But that's very speculative, but it's an interesting,
interesting thought.
