Beautiful, graphic rich slides to engage students based on Essential Environment by Withgott and Laposota. Slides cover Chapter 3 evolution, biodiversity and population ecology
2. Hazards of Living in Japan: First
an earthquake, then a tsunami,
then a nuclear meltdown… now
radioactive boars
• http://www.cbsnews.com/news/fukus
hima-japan-potentially-radioactive-
wild-boars/
• No wonder they’re not having any kids!
• Each boar weighs 200 lbs
• Boars contain high levels of radioactive
element caesium-137, which is 300
times above the safe limit for
consumption
Hmmm…. Another example of where
an adaptable opportunistic species
comes in and just takes over.
Prepared by Kiersten Lippmann, 2017
3. So… no eating the boars!
• Boars are aggressive
towards humans
• “It is not really clear now
which is the master of the
town, people or wild boars,”
Tamotsu Baba, mayor of
Namie, told Reuters. “If we
don’t get rid of them and
turn this into a human-led
town, the situation will get
even wilder and
uninhabitable.”
Prepared by Kiersten Lippmann, 2017
4. Saving Hawaii’s Native Forest Birds
• Hawaii has many new and
unique species of bird
• Half of Hawaii’s bird species (70
of 140) have gone extinct in
recent times
• Many remain on brink of
extinction
Prepared by Kiersten Lippmann, 2017
5. Saving Hawaii’s
Native Forest
Birds cont..
• Hawaii’s forests under siege
starting with Polynesian settlers
• Cut forests
• Introduced non-native pigs, goats,
mongooses, and cattle who ate
non-native plants and the eggs
and young of ground-nesting birds
• Invasive plants introduced and
spread across the altered
landscape
Prepared by Kiersten Lippmann, 2017
6. Hawaii’s forest
birds- avian
malaria/pox
• Avian pox and malaria arrived with
introduced mosquitos
• Native fauna not adapted to resist
these pathogens
• Killed off native birds everywhere
except on high mountain slopes,
where it gets too cold for
mosquitoes to survive
• Few native birds exist below
1500m elevation on Hawaii’n
islands
Prepared by Kiersten Lippmann, 2017
7. Saving Hawaii’s forest
birds cont..
• Fenced out pigs
• Planted thousands of native plants in
deforested areas
• Restored native forests now growing on
thousands of acres
• Climate change presents new challenges
• As temperatures climb mosquitoes move
upslope, spreading disease
• New strategies needed to preserve flora
and fauna bounty of millions of years of
evolution on the unique Hawaiian Islands.
Prepared by Kiersten Lippmann, 2017
8. Evolution: the source of
Earth’s biodiversity
• Species- a population or group of populations whose
members share characteristics and can freely breed
with one another and produce fertile offspring
• Population- a group of individuals of a given species
that live in a particular region at a particular time.
• Evolutions- change in populations of organisms from
generation to generation. Changes in genes often lead
to modifications in appearance or behavior
• Species adapt to their environments and change over
time
• Evolutionary processes influence many aspects of
environmental science including agriculture, pesticide
resistance, medicine, and environmental health
Prepared by Kiersten Lippmann, 2017
9. Natural selection shapes
organisms
• Natural selection- inherited characteristics that enhance survival
and reproduction are passed on more frequently to future
generations than characteristics that do not, altering the genetic
makeup of populations through time.
• Natural selection is the primary mechanism of evolution
• Organisms face a constant struggle to survive and reproduce
• Organisms tend to produce more offspring than can survive to
maturity
• Individuals of a species vary in their attributes
Variation is due to differences in genes, environments in which
genes are expressed, and interactions between genes and the
environment
10. Natural Selection
• Attributes are passed from parent to offspring
through genes
• A parent that produces more offspring will pass
on more genes to the next generation than a
parent who produces few or no offspring
• Next generation, the genes of the better-
adapted individuals will outnumber those of
less well-adapted individuals
• Adaptation- over generations, characteristics,
or traits (Adaptations/adaptive traits), that
lead to better and better reproductive success
in a given environment will evolve in the
population.
Prepared by Kiersten Lippmann, 2017
11. Selection acts on
genetic variation
• Genes must code for a trait, for an organism to
pass the trait on to future generations
• Mutations- accidental changes in DNA within
the cell
• If mutation is in sperm or egg cell, it may be
passed on to next generation
• Most mutations have little effect, some are
deadly, some beneficial
• Non-lethal mutations provide genetic variation
on which natural selection acts
Prepared by Kiersten Lippmann, 2017
12. Natural Selection cont….
• Sexual reproduction can result in genetic variation
as well through novel gene combinations
• Genetic variation can help populations adapt to
changing environmental conditions
• Example- roughly 10% of little brown bats are
resistant to white nose syndrome
• Environmental conditions determine what
pressure natural selection will exert, which affect
which members of the population will survive and
reproduce.
Prepared by Kiersten Lippmann, 2017
13. Natural Selection Cont…
• Divergent evolution- closely related species
that live in different environments tend to
diverge in their traits due to selective
pressures
• Convergent evolution- unrelated species living
in similar environments in separate locations
independently aquire similar traits as they
adapt to selective pressure
Prepared by Kiersten Lippmann, 2017
14. Evidence of
selection is all
around us
• First proposed in 1858 by Charles Darwin
and Alfred Russel Wallace, British
Naturalists
• On the Origin of Species
• Birth of modern evolutionary biology
• Explained how organisms traits change
over generations
• Artificial Selection- selection for
domesticated animals that possess traits
we want or like, called selective breeding
• Led to variety of domestic dog breeds
• Crop plants and livestock
• Entire agricultural system is based on
artificial selection
Prepared by Kiersten Lippmann, 2017
15. Understanding evolution is
vital for modern society
• Evolutionary processes play a vital role in
today’s society and our lives
• Food we eat (selective breeding)
• Medical advances (understanding infectious
disease- like strains of influenza)
Prepared by Kiersten Lippmann, 2017
16. Evolution generates biodiversity
• Just as in crops, pets, and livestock, evolution can elaborate
and diversify traits in wild organisms
• Life’s complexity expressed as biological diversity or
biodiversity
• Includes all levels- species, genes, populations, communities
• 1.8 million species described so far
• Many remain undiscovered or unnamed
• Example- 500 species Hawaiian fruit flies, but identified
about 500 yet formally named and described… there are
probably still more… (for what that’s worth)
• Diversity of species is found everywhere, plants, microbes,
even Antarctic ice harbors microbes
• Soil outside contains high number of species including
insects, mites, millipedes, nematode worms, plant seeds,
fungi, millions of bacteria
17. Speciation produces new types of organisms
• Earth came to have so many species through
speciation
• Allopatric Speciation is the main way- where
species become physically separated (lava floes,
climate change, timber harvest, sea level rise,
or flying or moving to another area).
• Once separated, populations evolve unique
traits on their own
• Eventually, the two populations can no longer
mate and form two separate species
18. We can infer the history of life’s diversification
• Innumerable speciation events have
generation complex patterns of diversity
• Histories of divergences are represented in
phylogenetic trees
• The branches illustrate hypotheses to how
divergence took place
• Show relationships among species,
populations, or genes
• Using a phylogenetic tree, we can map traits
onto the tree, and trace when in
evolutionary history those traits appeared
• Also used by taxonomists to identify species
Prepared by Kiersten Lippmann, 2017
19. Extinction and # of species
• The fossil record shows the # of species has
increased over time, but just a small fraction
of the species that ever existed are alive
today
• Complexity has evolved, but when conditions
are right, less complex species evolve
• Animals have evolved some incredible
adaptation- photosynthesis, hearts that beat
for a lifetime, eyes, brains…
• Extinction is the disappearance of species
from Earth.
• Species on average spend 1-10 million years
on Earth.
• Number of species in existence is equal to the
number added through speciation minus the
number removed by extinction.
Prepared by Kiersten Lippmann, 2017
20. Some species are
especially
vulnerable to
extinction
• Extinction generally occurs when
environmental conditions change
rapidly or drastically enough that a
species cannot adapt genetically to
the change- natural selection is not
give time to work
• Small populations vulnerable
• Endemic species vulnerable
• Endemic species are found in a
particular region and nowhere else
• Island dwelling species vulnerable
• Ex. Only one land mammal- bats-
naturally found in Hawaii so birds
evolved to be ground nesting… taken
out by introduced mammals
Prepared by Kiersten Lippmann, 2017
22. Earth has seen episodes of mass extinctions
• Background extinction rate- one
species at a time
• 5 mass extinction events that killed
off massive #s of species all at once
• Wiped out 50- 95% of species each
time
• 65 million years ago wiped out
dinosaurs- collision of asteroid
• 250 million years ago, 75% to 95%
of all species perished – probably
massive volcanism
Prepared by Kiersten Lippmann, 2017
23. The sixth mass extinction is upon us
• We are the cause
• Human population growth and
resource depletion
• Many species extinct, many more
close to extinct
• Loss of species is irreversible
• Biodiversity affects us directly-
organisms provide food, fiber,
medicine, ecosystem services
• Loss of biodiversity threatens our
survival
Prepared by Kiersten Lippmann, 2017
24. Ecology and the
Organism
• Ecology- scientific study of the interactions
among organisms and relationships between
organisms and the environment
• Explains and predicts the distribution and
abundance of organisms in nature
• Ecology and evolutions are intertwined
Prepared by Kiersten Lippmann, 2017
25. Ecology is studied at several levels
• Levels begin with cells up to
biosphere
• Biosphere- cumulation of all
living things on earth and the
areas they inhabit
• Ecologists- study relationships at
higher levels of the hierarchy
• At organismal level, ecology
describes relationships between
an organism and physical
environment
Prepared by Kiersten Lippmann, 2017
26. Population Ecology vs.
Individual Ecology
• Ecology describes the
relationship between an
organism and its physical
environment
• Population ecology examines
the dynamics of population
change and the factors that
affect the distribution and
abundance of members of a
population.
27. Ecology- key concepts and terms
• Community- an assemblage of interacting
populations that inhabit the same area (ex:
organisms at 2,000 feet in WMNF)
• Community ecology- focuses on patterns of
species diversity and interactions among
species (eg. Predator prey and competition)
• Ecosystems- encompass living biotic
communities and abiotic materials and forces
with which communities interact (air, water,
soil, nutrients)
• Ecosystem ecology- flow of energy and
nutrients in a system by studying living and
non-living components.
• Landscape ecology- driven by widescale
changes like climate change, helps us
understand how and why ecosystems,
communities, population are distributed
across geographic regions.
• Expanding to study of the biosphere as a
whole with new technologies and understanding
Prepared by Kiersten Lippmann, 2017
31. Extinction of Passenger Pigeon
• Video- 100 year anniversary of
extinction of passenger pigeon
• Video- preview of passenger
pigeon documentary, includes
simulation of migration flights of
passenger pigeons