Transcript Introduction to Evolution

Introduction to Evolution
Aidan Budd
SCB, EMBL-Heidelberg
EMBL PreDoc Course
Evolution Module
Monday 5th December 2011
Aidan Budd, EMBL Heidelbe
Introduction
Aidan Budd, EMBL Heidelbe
It was...
• a multi-deadline weekend
• so I didn't get the preparation time I wanted
• I've tried to fit it to the context of the module and the
course
• i.e. you're tired
• i remember - I did this myself in 2000
• trying to make it interactive/less passive
• but please bear with me
Aidan Budd, EMBL Heidelbe
Aim
• Highlight some themes common to most (all?)
discussions of biological/Darwinian evolution
• Hope this makes it easier to notice
links/relationships between presentations etc. in this
module
• Hope this helps think about topics in a more general
way, making it easier to deconstruct/critique such
analyses
• Feels like quite a lot of hope for a Monday morning
Aidan Budd, EMBL Heidelbe
Focus
• On you and your current ideas on evolution
• You are impressively heterogeneous
• Difficult to present introductory content that won't be much
too detailed for "half" of you and much too basic for the
other half
• Those with more experience on the topic are encouraged to
support those with less
• Try to address this by having you think on your own, and
talk in groups, about specific topics/issues of
interest/relevant to you
• some people learn better like this
• hopefully it helps us all stay awake
Aidan Budd, EMBL Heidelbe
What do we mean by
"evolution"?
Aidan Budd, EMBL Heidelbe
What do we mean by "evolution"?
1.try to write, on your own, without discussing it, a definition of
the topic we discuss when talking about Darwinian/biological
evolution
• make notes on which topics/issues you think need to be in the definition
• makes notes on other terms you might want/need to carefully define to
support this defenition
• if you have trouble, try to make notes on what you find difficult about this
• I'll tell you when to stop
2.compare your definition with your neighbour
• try and write a consensus one you both agree on
• if this is difficult, try to make notes on where the problems might come
from
Aidan Budd, EMBL Heidelbe
What do we mean by "evolution"?
• we'll discuss these definitions as a group
• I'll describe what I want in such a definition
• a volunteer will give their definition, and any particular problems they
encountered with producing it
• ask you for any important differences with your definitions
Aidan Budd, EMBL Heidelbe
Evolution - a Process of
Transformation/Change
the change in the inherited traits of a population of
organisms through successive generations.
Futuyma, Douglas J. (2005). Evolution. Sunderland, Massachusetts: Sinauer Associates, Inc. ISBN 087893-187-2.
the change in the gene pool of a population from generation to
generation by such processes as mutation, natural selection, and
genetic drift.
Random House Dictionary
the historical development of a biological group (as a race or species)
a theory that the various types of animals and plants have their origin in
other preexisting types and that the distinguishable differences are due
to modifications in successive generations; also : the process
described by this theory
Merriam-Webster Dictionary
the process of change in lifeforms over generations
wikipedia
Aidan Budd, EMBL Heidelbe
Evolution - a Process of
Transformation/Change
the process of transformation
that produces differences
between ancestors and
descendants that are not due
to direct environmental
influences
driven by genetic differences
between ancestors and
descendants
Aidan Budd, EMBL Heidelbe
•Why are we interested in evolution?Ke
Aidan Budd, EMBL Heidelbe
Focus on you...
What do you see as the most interesting
aspects/implications/applications of evolutionary biology?
What do you consider some of the more important common
misunderstandings people have of evolutionary biology?
What are key issues/topics in evolutionary biology you feel it is
important to understand to be able to critically assess/interpret
evolutionary analyses
Your opinions on these issues have considerable impact on how
you approach a discussion of evolutionary biology
So it's useful to examine/highlight/consider these opinions and
how they might differ from other people's
Aidan Budd, EMBL Heidelbe
Exercise
You are making a short film to be shown at the start of an exhibition of
evolutionary biology at a natural history museum
The film should
• excite the audience about the topic address common
misunderstandings you expect they might have teach them about
several key, basic principles of how evolution occurs
Make notes, silently, on your own, on:
1. the aspects of the topic that you think would make the audience excited by it
2. common misunderstandings you would want to address
3. some basic, key principles about how evolution occurs that you would want to
address
Aidan Budd, EMBL Heidelbe
Make notes, silently, on your own, on:
1. the aspects of the topic that you think would make the audience excited by it
2. common misunderstandings you would want to address
3. some basic, key principles about how evolution occurs that you would want to
address
Example:
1. Comparison of dog (Canis lupis) and marsupial wolf (Thylacinus cynocephalus)
skulls - astounding convergent evolution (can show you if you're interested...)
2. Humans evolved from chimpanzees
3. That genetic changes that drive evolution are not all "adaptive" i.e. evolutionary
changes are not just the result of natural selection
Choose a favourite for each of these points in discussion with your neighbour,
then we'll find out what we've come up with
Aidan Budd, EMBL Heidelbe
What about Darwin...?
• Theories accounting for observed biodiversity that
implied historical change of species existed before
Darwin
• Darwin provided simple, mechanistic, "algorithmic"
explanation
this might
occur
1-Organisms
pass for
theirhow
characteristics
on to
their descendants, which are
mostly but not completely identical to their parent organisms. 2Organisms breed more descendants than can possibly survive. 3Descendants with beneficial variations have a better chance of surviving
and reproducing, however slight, than those with non-beneficial
variations. 4-These slightly modified descendants are themselves
organisms, so repeat from step 1. (There is no stopping condition.)
Aidan Budd, EMBL Heidelbe
What about Darwin...?
• Mechanistic explanation is powerful as it allows us to
make predictions
• Key further development was integration with genetics
to form the "new synthesis" - the substrate on which
inherited evolutionary changes occur
Aidan Budd, EMBL Heidelbe
Right Here, Right Now
http://www.youtube.com/watch?v=ub747pprm
J8
• A video for a Fatboy Slim track that references
evolution
• While we're watching it, make notes on:
• What (if anything) it "gets right" about how we think about
evolution?
• In what way does the video misrepresent the way we
believe evolution occurs?
• Do you think there is a danger that this misrepresentation
could cause serious trouble for people's ability to
understand
we thinktoreally
happened?
Why?
• Discuss
yourwhat
answers
these
questions
with your
neighbour - we will then discuss them together
Aidan Budd, EMBL Heidelbe
Further reading
• Darwin's Dangerous Idea, D Dennett
• http://www.ucmp.berkeley.edu/exhibits/historyoflife.
php
• http://tolweb.org/tree/phylogeny.html
Aidan Budd, EMBL Heidelbe