Download Biodiversity and Natural Selection Notes

BIODIVERSITY AND
NATURAL
SELECTION NOTES
ESSENTIAL QUESTIONS:
HOW ARE LIVING THINGS INTERCONNECTED?
EXPLAIN ADAPTATION.
WHAT IS THE DIFFERENCE BETWEEN NATURAL SELECTION
AND SELECTIVE BREADING?
HOW DOES AN ENVIRONMENT
SUPPORT LIFE?
• Habitat
• A specific place where an organism lives
• Support life since they have conditions that suit the organisms that
live there
• Microhabitat
• A very small, specialized habitat
• Garden
• School yard
WHAT IS BIODIVERSITY?
• The number and variety of plants, animals,
and other organisms living in an area
• Describes the many genetic traits observed
within a given species
• The variation of genes within a species
WHY IS BIODIVERSITY
IMPORTANT FOR ECOSYSTEMS?
• An ecosystem with a high level of biodiversity has
many different species that constantly interact
with each other and the environment
• High biodiversity makes the ecosystem more
stable when faced with an environmental change
WHY IS BIODIVERSITY
IMPORTANT FOR HUMANS?
• We are part of the ecosystem
• We depend on other organisms to help keep the
environment suitable for our life and health
• We depend on other species for:
• Medicines, food, materials for clothing, etc.
WHAT IS SUSTAINABILITY?
• Sustainability
• The ability of the environment to meet human needs
indefinitely
• We depend on access to clean air, clean fresh water, fertile
soils, mineral deposits, and other important natural resources.
• Overpopulation and over use of resources has led to habitat
loss and pollution of air, water, and soil
WHAT IS A POPULATION?
• Species
• A group of organisms that can reproduce only with one another and
not with other organisms
• Population
• A group of organisms of the same species that live in the same
place at the same time.
• Classifying organisms allows us to better understand how they
interact in nature
WHAT IS VARIATION?
• Variation
• The differences that occur in individuals within a
species
• Partly due to the genetic variations of the individuals
• Mutation
• Change in DNA
WHY IS VARIATION
IMPORTANT?
• Genetic variation results in a population
that improves survival changes of certain
species
• No genetic variation = no change in the
population = easier for extinction
WHO IS CHARLES DARWIN?
WHAT DID HE OBSERVE?
• Was a naturalist
• Observed land forms and collected fossil and
animal specimens from the Galapagos Islands,
specifically Mockingbirds
• Formed his ideas about how populations could
evolve
WHO IS CHARLES DARWIN?
WHAT DID HE OBSERVE?
• Darwinism is a theory of biological evolution
• states that all species of organisms arise and
develop through the natural selection of small,
inherited variations that increase the individual's
ability to compete, survive, and reproduce
WHAT IS NATURAL SELECTION?
• The process by which organisms that inherit helpful
traits tend to reproduce more successfully than
other organism
• Four parts that contribute to evolution by natural
selection:
• Overproduction, Genetic variation, selection, and
adaptation
WHAT IS ADAPTATION?
• An inherited trait that improves survival and reproductive success of an
organism
• Selection can work only on traits that exist in a population.
• Individuals with a helpful trait are more likely to survive to reproduce
• As a result, the helpful trait, or adaptation, is “selected” for
• The adaptation is passed onto the next generation and over time becomes
more common in the population, as long as the trait remains adaptive
HOW DO SPECIES CHANGE OVER
TIME?
• Parents and offspring often have small
genetic differences between them
• Over many generations, the small differences
may add up to larger genetic differences in
later populations
HOW DO SPECIES CHANGE OVER
TIME?
• The spread of antibiotic resistance genes in
bacterial populations is an example of the
benefits adaptations can have for a
population
• The genetic makeup of several bacterial
species and populations has changed over
time because they inherited resistance genes
from earlier generations
HOW CAN ADAPTATION LEAD TO
SPECIES SURVIVAL?
• For populations and entire species to survive, individuals must
survive to reproduce.
• Adaptations help organisms survive in their environment
• If a population does not have individuals with traits that would
help them survive in a changed environment the population may
decline; at worst, the entire species may die out
WHAT IS SELECTIVE BREEDING?
•The practice by which humans breed specific
plants or animals for desired traits