Adaptations and Evolution DO NOW: How are these animals adapted to their environment?
Adaptations for Survival
Feathers, wings, and the hollow bones of birds are examples of… (1) adaptations for flight (2) responses to stimuli (3) unnecessary body parts (4) reproductive structures
The diagram below shows the head structure of four different birds. The birds’ beaks show how the birds (1) compete for the same food in their community (2) require different amounts of food for survival (3) store food for the winter months (4) are adapted to get food from different sources
Can we create adaptations? Seedless watermelon Tangelo Labradoodle
Selective Breeding: process of breeding plants and animals for particular traits (also known as artificial selection) _____________________________________________________________________________________________________________________________________________
The illustration below traces the development of the corgi dog over several generations as a result of human activity. This is an example of the human activity called (1) mutation (2) genetic engineering (3) selective breeding (4) natural selection
A research team wanted to produce a smaller variety of German shepherd dogs. They mated the smallest dogs from different litters for several generations. This is an example of which concept? (1) extinction (2) selective breeding (3) mutation (4) natural selection
Mutations occur naturally at random intervals. Is selective breeding the only way changes can occur in living organisms? No, Mutations occur naturally at random intervals.
Mutations: Error in the genetic code on the DNA resulting in a change in the appearance or function of the organism. Mutations create variations in the gene pool.
Although change in multicellular species usually takes thousands of years, some species of bacteria undergo major changes in just a few years. One reason for this difference is that these bacteria … (1) are microscopic (2) do not contain DNA (3) reproduce very quickly (4) cause infectious diseases
Which group of organisms can show significant trait changes in the shortest period of time? (1) bacteria (2) fish (3) birds (4) reptiles
Which event is the best example of competition between species in a pond environment? (1) dragonflies landing on lily pads (2) frogs and toads eating flies (3) lizards and snakes lying in the sun (4) hawks eating mice
Charles Darwin Father of Evolution Proposed a mechanism for evolution, natural selection Darwin went on a 5-year trip around the world on the ship, the HMS Beagle As the ship’s naturalist, he made observations of organisms in South America and the Galapagos Islands Wrote a book, “Origin of the Species”
Darwin’s Finches
Natural Selection Natural Selection: Organisms that are best adapted to an environment survive and reproduce more than others
1. Overproduction Each species produces more offspring than can survive
2. Variation Each individual has a unique combination of inherited traits. Adaptation: an inherited trait that increases an organism’s chances of survival
Why is Variation Important? Because the environment changes. The more variation within a species, the more likely it will survive EX: If everyone is the same, they are all vulnerable to the same environmental changes or diseases
3. Competition Individuals COMPETE for limited resources: Food, water, space, mates Natural selection occurs through “Survival of the fittest”
4. Selection The individuals with the best traits / adaptations will survive and have the opportunity to pass on it’s traits to offspring. Natural selection acts on the phenotype (physical appearance), not the genotype (genetic makeup) Ex: When a predator finds its prey, it is due to the prey’s physical characteristics, like color or slow speed, not the alleles (BB, Bb)
Peppered Moth A Which moth will the bird catch? B
Evidence for Evolution Fossils: a record of the history of life on Earth
Homologous Body Structures Homologous Body Structures: similar anatomy in different types of animals because of common ancestor
Vestigial Organs Vestigial Organs: “leftover” traces of evolution that serve no purpose
Embryology Embryology: embryos of all vertebrates are very similar early on
Biochemical Evidence Biochemistry: DNA with more similar sequences suggest species are more closely related EX: Humans and chimpanzees share more than 98% of identical DNA sequences
Coral Snake (Poisonous) Milk Snake (Not poisonous)
Stick Mantid
Flower Mantid