How many species of snakes are there in Alberta? • A. 0 • B. 4 • C. 10 • D. 20 • How many species of true frogs occur in Alberta? • A) 0 • B) 3 • C) 10 • D) 30 • http://www.daversitycode.com/
Science 9 Topic 1
Biological Diversity (AKA Biodiversity) • What do you think biodiversity means? • How would the environment change if one species of plant or animal disappeared forever?
Biodiversity • Biodiversity • The number and variety of organisms found in an area • Think of an area that would have high biodiversity? • Jungle, rain forest • Think of an area that would have low biodiversity? • Areas with extreme conditions (e.g. The North Pole, Many Deserts) • Scientists estimate that there are between 3 million and 100 million species on earth today. • Most of these species have yet to be discovered.
Importance of Biodiversity • Imagine a new mosquito eating bird is introduced in to Alberta. What might happen? • The number of mosquitos would decrease due to the addition of a new predator. The number of animals who feed on mosquitos would decrease. Animals who feed on these animals would also decrease. The number of birds would increase as they have no natural predators. • What happens if we destroy a plant or animal species without knowing what the effects may be? • E.g. The Pacific Yew Tree produces cancer fighting chemical, Taxol. • We may be destroying plants or animals that may one day save human lives. We cannot be sure what will happen if a species of plant or animal get destroyed.
Importance of Biodiversity • Studies have shown that natural communities are better suited for survival if they have a more diverse population. • Why?
Variations • Variation • Difference in Characteristics • Can occur between different species or between the same species.
Variations Between Species • plants make their own food, animals can not • number of legs • type of mobility • feathers/fur/scales • mammals nurse their young young
Variety Within a Species • species • a group of organisms that interbreed naturally to produce fertile offspring • a male donkey and female horse can be crossed to produce a mule • the mule is infertile, therefore the donkey and horse are separate species • lions and tigers can also produce offspring (tigons and ligers) but these offspring are also sterile • a great deal of variation exists between members of the same species • Zebra stripes have different patterns. • Dalmatian pups have no spots, unlike their parents. • Yellow, fluffy chicks look different than adult chickens.
Adult Chicken Baby Chick
Speciation • The development of a new species. • Speciation can be due to geographic separation (separation by space) • E.g. Polar Bears • ~1.5 million years ago black bears were geographically separated. • Some bears were isolated in cooler the Northern climates. • Over time these bears adapted to the harsher climate • Lighter fur, webbed feet, more fat, insulating fur • A separate species of bear emerged • E.g. Darwin’s Finches • Finches developed beaks more suited to the conditions of the island they inhabited • Fiches on different islands are a different species
Variations • Variations for Survival • Every organism has adaptations that allow it to survive in its environment. • Structural Adaptation • a physical feature that increases an individual’s chances of survival • E.g. fins, webbed feet, night vision. • What are structural adaptations that help organisms survive the cold climate of the Arctic?
Adaptations of the Arctic • Feet that can walk on snow like snow shoes • Heavy fur coat • Lots of fat/blubber • Lots of feathers
Variations • Behavioral Adaptations • A behavior that increases an individuals chance for survival • E.g. migration of caribou, hibernation of bears, etc. • value of variation • Variation helps a species to survive • When organisms are more varied physically and behaviorally, it is more likely that some individuals of the species will possess traits that will help them to resist a hardship. • If all the species were identical, changes in environment may eliminate the entire species. • ex) Influenza pandemic of 1918-1919, those who survived probably had some special resistance. • Variation also enriches the beauty of the environment