What's the difference? - University of Birmingham

The Birmingham Magazine 27
Fascinating evolution
Dr Jeremy Pritchard, School of Biosciences
Darwin’s radical ideas were Birmingham
born and bred. Both his grandfathers, Josiah
Wedgwood, the potter, and Erasmus Darwin,
the doctor and polymath, were influential
members of the Birmingham Lunar Society,
discussing and promoting the ideas of change
in society that preceded those in biology.
Today evolution underpins research in the
School of Biosciences. Topics as diverse as
the spread of bacterial resistance to antibiotics
through to the formation and extinction of
whole species under climate change are
actively studied in the School.
Bacteria are subject to the same evolutionary
laws as all other organisms on the planet.
The discovery of antibiotics has had a
positive influence on human health but is
being undermined by the ability of bacterial
populations to evolve resistance to these
medicines. Bacterial genomes are subject
to random mutations, some of these genetic
changes allow the bacteria that possess
them to overcome the effects of the antibiotic,
while those that do not die. The fitter, resistant
bacteria reproduce and so the genes for
resistance increase in the population, resulting
in the serious medical problem that exists today.
Work in the School of Biosciences is
engaged in the arms race against antibiotic
resistant bacteria, designing new antibiotics
by studying the biochemistry of antibiotic
metabolism in Pseudomonas species to help
generate new antibiotics that can be used
against bacteria such as the superbug MRSA.
Evolution is inherently fascinating and
provides a vehicle to enthuse people about
science and engage people of all ages. The
School runs a comprehensive outreach and
Public Understanding of Science programme,
including components supporting the teaching
of evolution.
Our research is widely disseminated:
Birmingham members of the Society of
Experimental Biology organised a scientific
session at the annual meeting in Glasgow
bringing together topics of plants, animals
and cells using systems ranging from genes,
proteins, cells and organisms to ecology.
In a lecture entitled Am I an Ape? Dr Susannah
Thorpe and I asked the audience to participate
in a series of exercises examining our
relationship with our ape cousins.
Another highlight of this Year of Darwin
was the project The Eye of the Beholder by
Biosciences artist in residence Franziska
Schenk. Inspired by Darwin’s iconic description
of the development of the eye, Fran is
producing a series of works forming the
centrepiece for public engagement activities
in the Year of Darwin 2009 and beyond. The
series of paintings draws on novel biomimetic
materials and methods that mirror the
process of evolution.
Our efforts to promote understanding of
science and evolution are well received and
contribute to education at all levels. However,
you are no doubt aware of the ‘debates’
between science and creationism. It is perhaps
gratifying that our efforts occasionally induce
reaction from these quarters.
Happily, most recognise that there is no
conflict between science and religion, with
clear separation of the physical and spiritual
world. We continue to promote good science
and counter the arguments of those suggesting
alternatives to evolution of creationism,
irreducible complexity and intelligent design.
At the age of 200 we think Charles Darwin
would be pleased with the development of his
ideas and the ongoing role of the University of
Birmingham in their evolution.
Walking the walk:
the evolution of
human bipedalism
Dr Susannah Thorpe, Lecturer in
Locomotor Ecology and Biomechanics,
School of Biosciences
Walking with an upright body on two legs
(bipedalism) is thought to be the first
anatomical adaptation that made human
ancestors unique from the ancestors of
our closest living relative, the chimpanzee.
Understanding how and why bipedalism
evolved underlies our understanding of all
human evolution and not surprisingly it has
been a subject of considerable debate.
Over the past 50 years many theories have
been proposed as to why bipedalism evolved.
For example, researchers have proposed that
human ancestors, smaller and weaker than the
other apes, were forced out of receding forests
between five and ten million years ago, and
landed, rather fortuitously, on the banks of
marine habitats where there was an abundance
of accessible aquatic food resources, and
where habitual bipedalism evolved in response
to wading through shallow water while
foraging. Though compelling, the Aquatic Ape
theory lacks any fossil evidence in its support.
This example demonstrates the limitations of
speculating; we can only look at the role of
bipedalism today and backdate to six million
years ago, an approach that clearly ignores
the way in which evolution occurs.
As a consequence, modern research
has started to focus more on how bipedalism
evolved. The traditional hypothesis argues that,
because chimpanzees and gorillas knucklewalk
(on all fours but with their fingers partially
flexed) on the ground, then the origins of
bipedalism must be understood in this context.
Others have noted that when climbing up
vertical tree trunks, the great apes extend their
legs in a manner that would ‘preadapt’ the body
for bipedalism; that is to say that the adaptation
of bipedalism would be a relatively easy affair
for an animal that was good at vertical climbing.
Although these theories have dominated
discussion for the past 30 years, the evidence
for both is highly contested and relatively weak.
Darwin in fact was probably rather closer to the
truth when he observed in The Descent of Man
that: ‘Monkeys exhibit a manner of progression
intermediate between that of a quadruped and
a biped, but…the anthropomorphous apes
approach in structure more nearly to the
bipedal than to the quadrupedal type’.
Through studying the locomotion of wild
orangutans in Indonesia, my research has shown
that orangutans, another close relative of humans,
use bipedalism when moving in the trees to
access the most flexible branches at the fringes
of tree crowns, where the majority of tasty fruits
and the narrowest gaps between tree crowns
(necessary for safe arboreal travel) are situated.
Since all the great apes exhibit bipedalism in
some form, we have suggested that bipedality
was probably present in the common ancestor of
all the great apes, some 16–20 million years ago,
meaning that bipedalism is not in fact a defining
feature of humanity, but rather a general ape
adaptation that has simply become more
specialised in humans.
Darwin observed in The Descent of Man
that: ‘the orang… is one of the most peculiar
and aberrant forms to be found in the Order’.
It is rather pleasant, therefore, that they have
emerged as one of the best living analogies for
such a crucial component of human evolution.
This research has radically changed the way we
view human evolution, since it necessitates a
scenario in which chimpanzees and gorillas
evolved from a somewhat orangutan/human form,
rather than the traditional view that humans are
more ‘evolved’ than the other apes. It is thus an
exciting time to be a researcher in human
evolution and we have many questions that
we still need to answer.