Evolution and Ecology Roadmap
We wish to know:
• Where we are going
• Why we should care
• How the pieces fit
together
http://tolweb.org/tree/
phylogeny.html
My Themes
• Human-induced changes to the planet need
to be understood within the context of
natural processes and evolutionary change
• Not just climate change: global
deforestation and desertification, overharvested resources, global homogenization
of species, altered mineral cycles
• Life diversity and life processes are at risk
The approximate number of pirates vs the average global
temperature for the past 200 years. A statistically
significant decline in number of pirates with rising global
temperature is clearly evident.
We need to be educated consumers of information!
Evolution and Ecology Roadmap
• Where we are going….
– The study of origins, the generation of life diversity, ‘the
ecological theatre and the evolutionary play.’
• Why we should care.
– Environmental change impacts our lives.
– Many important issues have a substantial scientific
component: teaching of intelligent design, legalization of
stem cell research, cloning, preservation of nature.
– Importantly, these issues also have significant moral and
ethical implications.
• How the pieces fit together.
– Time and earth history; Climate; Biodiversity and
ecosystem function.
Efforts to Reconcile God and Nature
Charles Darwin
1809 - 1882
Public Acceptance of Evolution
“Human beings, as we
know them, developed
from earlier species of
animals.”
True or false?
Asked since 1985
Miller JD, Scott EC, Okamoto, S (2006)
Public acceptance of evolution. Science
313:765-766.
http://www.venganza.org/
On The Origin of Species by Means of Natural Selection,
or
The Preservation of Favoured Races in the Struggle for Life
by Charles Darwin
First Edition, 1858
In order to pass the B.A. examination, it was, also, necessary
to get up Paley's Evidences of Christianity, and his Moral
Philosophy. . . The logic of this book and as I may add of his
Natural Theology gave me as much delight as did Euclid. The
careful study of these works, without attempting to learn any
part by rote, was the only part of the Academical Course
which, as I then felt and as I still believe, was of the least use
to me in the education of my mind. I did not at that time
trouble myself about Paley's premises; and taking these on
trust I was charmed and convinced of the long line of
argumentation.
Charles Darwin. Autobiography
Natural Theology: or, Evidences of the Existence
and Attributes of the Deity, Collected from the
Appearances of Nature. Published 1802
William Paley
(1743 – 1805)
“. . . when we come to inspect the watch, we perceive. . . that its
several parts are framed and put together for a purpose, e.g. that
they are so formed and adjusted as to produce motion, and that
motion so regulated as to point out the hour of the day; that if
the different parts had been differently shaped from what they
are, or placed after any other manner or in any other order than
that in which they are placed, either no motion at all would have
been carried on in the machine, or none which would have
answered the use that is now served by it. . . . the inference we
think is inevitable, that the watch must have had a maker..”
To account for the often amazing adaptations
of animals and plants, Paley argued that only
an intelligent Designer could have created
them, just as only an intelligent watchmaker
can make a watch
The Selfish Gene
In its preface, Dawkins states that he
wrote the book "to persuade the
reader, not just that the Darwinian
world-view happens to be true, but
that it is the only known theory that
could, in principle, solve the mystery
of our existence."
Wikipedia – the free
Encyclopedia
Changing How We Think
• Darwin tells us that human origins can be
explained solely by natural processes.
– Life, and by inference the universe, is without
design or divine purpose.
• Dawkins tells us that selfish hereditary
molecules live forever (or until they mutate);
Humans are their temporary vessels.
– Evolution is selfish rather than altruistic.
Can Science and Religion Be
Reconciled?
• Separate realms,
each of value
• Too disparate for
any reconciliation
Darwin’s Theory of Evolution
• Organisms have changed over
time; Those living today are
different than they were in the past
• All organisms are derived from
common ancestors by a process of
splitting, or speciation, that gave
rise to the entire tree of life
• Change is gradual and slow, taking
place over a long time
• The mechanism of evolutionary
change is natural selection
The Aftermath
“Was it through his grandfather or his
grandmother that he claimed his descent
from a monkey? “
Oxford, June 30, 1860: bishop Wilberforce
question to evolutionist Thomas Huxley,
known as “Darwin’s bulldog” for his
vigorous defense of Darwin’s theories.
The Steady March of New
Evidence
• Scientists in Spain discovered fossils of
ape species from about 13 million years
ago. This may have been last common
ancestor of all living great apes, including
humans. (NY times Nov 2004)
• A consortium of scientists recently
completed a first sequence of chimp
DNA. Comparison of similarities and
differences help us explore recent human
evolution and understand the genetic basis
of uniquely human traits.
(Nature 1 Sept 2005)
Pierolapithecus
catalaunicus
Why study chimpanzees?
• To better understand chimp and human evolution
• To ensure their survival
• A model species for the study of diseases (hmm…)
• Study of origins
Threats to the
Great Apes
Audubon.org
• Bushmeat trade
• Habitat loss
• Illegal capture for zoos and
experimentation
• Diseases (ebola), and from
humans (polio)
Today Gombe, only eight miles long
and one to two miles wide, is
surrounded by farms and people,
including thousands of refugees fleeing
violence in nearby countries.
Threats to Biodiversity
Human actions now threaten species and ecosystems to
an extent rarely seen in earth history.
Habitat
destruction
Over-harvest
Climate
change
Exotic species
Why Should We Care About
Biodiversity?
• The wonder of nature
• Ecosystem goods and services
– Clean water, productive soils, the
recycling of nutrients, food and fiber,
recreation, spiritual renewal
• The accelerating rate of
species loss
• Emerging diseases
The March of the
Penguins,
narrated by
Morgan Freeman
http://www.divegallery.
com/Leafy_Sea_Drago
n.htm
Nature’s Services
Are Diverse Systems More
Productive?
Plant Biomass and Species Number
Hector et al. 1999 Science 286:1123
Genetic Diversity of Salmon Stocks
Hillborn et al. 2003 PNAS
100:6564
The Ecology of Infectious Diseases
Albrecht Durer's The Four Horsemen
of the Apocalypse
I looked, and there before me
was a pale horse! Its rider was
named Death, and Hades was
following close behind him.
They were given power over a
fourth of the earth to kill by
sword, famine and plague, and
by the wild beasts of the earth.
Revelations 6:7
The Threat of Infectious Diseases
Is Increasing
• Human activities continue to cause environmental
disruptions that can potentially favor new disease
emergence
• Most pathogens evolve rapidly
• Global travel facilitates rapid spread
The 1918 influenza affected 20-40
million people, and had a 5%
mortality rate. Ebola has an 80%
mortality rate. Current concern for
bird flu is justified.
Emerging Infectious Diseases
• EIDs: diseases that are, or have recently, increased in
incidence, impact, pathogenicity, geographical or host
range
• Causative agents of infectious diseases are among the
most ubiquitous organisms on the planet
• Typically capable of high rates of evolutionary
change, allowing them to adapt readily to new hosts
and habitats
• Examples include:
– Malaria, Lyme, WNV, dengue, Schistosomiasis
– SARS, HIV, Ebola, bird flu
Bushmeat Trade
• For the tropical forests of central and west Africa
(the Congo basin rainforests), greatest threat to
vertebrate species is over-hunting for subsistence
and commerce
• For people living in these areas, up to 90% of total
animal protein may be derived from wild animals
Will New Diseases Emerge ?
• Obviously this is difficult to forecast exactly
• HIV, Ebola and a number of diseases likely
‘jumped’ from primates to humans
• SARS went away – no-one knows why. The
wildlife host was never conclusively identified
• Bird flu currently infects a few people, in bird to
human exposure, under concentrated bird farming.
If bird flu adapts to human-to-human infection, an
outbreak is possible.
Biodiversity and Disease Dynamics
• The presence of a diverse assemblage of
vertebrates can dilute disease incidence
• Occurs when reservoir competence varies among
host species and the most competent reservoir host
tends to be a community dominant.
• Vertebrate communities with high species
diversity will contain a greater proportion of
incompetent reservoir hosts that deflect blood
meals away from the most competent reservoirs
(Ostfeld and Keesing, 2000 Can. J. Zool.)
Lyme Disease
• An example of the dilution effect occurs in the
ecology of Lyme disease, a tick-borne bacterial
disease prevalent in north America
• The principle reservoir, the white-footed mouse,
increases dramatically in abundance in fragmented
habitats that contain low vertebrate diversity (due
to loss of predators and competitors)
• More intact community assemblages effect a
decrease in mouse abundance, resulting in fewer
infected ticks and less disease risk to humans
Forest Fragmentation and Lyme
Disease Risk
My Themes
• Human-induced changes to the planet need
to be understood within the context of
natural processes and evolutionary change
• Not just climate change: global
deforestation and desertification, overharvested resources, global homogenization
of species, altered mineral cycles
• Life diversity and life processes are at risk
Possible Projects
• The influence of global
warming on coral reefs
• The bird flu pandemic of
2006
• Is Nemo a mutualist or a
commensalist?
• Rapid evolution in
Darwin’s finches
• Can reforestation
significantly slow global
warming?
• Loss of rainforests
threatens biodiversity
• How many kingdoms of
life are there?
• How much biodiversity is
needed to protect
ecosystem function?
• The effects of climate
change on nature reserves