Charles Darwin The “Origin of Species” Evolution by natural selection

CHARLES DARWIN Sailed around the world in the HMS Beagle

Galapagos Islands

Darwin’s Finches

Natural Selection

Sexual / Asexual Reproduction Type of ReproductionMethodsAdvantagesDisadvantages Sexual Internal fertilizationDiversity in offspring Better able to survive environmental changes Offspring less likely to have mutations show up Requires a mate to reproduce Uses energy to find/attract a mate Population increases are limited External fertilization Conjugation Asexual BuddingCan increase populations rapidly Does not require a mate for reproduction to take place Lack of diversity in offspring Lack of resiliency if conditions change Because they reproduce offspring genetically identical to parents, the offspring inherit any mutations of the parent. Spores Fission

Energy Spent In Mate Attraction What qualities do we as humans seek out in potential mates? Are they physical?

Sexual selection What feature is giving this bird an advantage? Is it a continuous or discrete trait?

Sexual selection

Where do new traits come from? Basically from mutations, which are oopseys in DNA copying Mutations happen randomly or are increased by uv light, x rays, gamma rays, chemicals, viruses, etc

Most mutations are not beneficial and many times are harmful But you never know, perhaps Stumpy’s extra foot could give him a competitive edge some where and then he and his offspring and their offspring, and so on … would be “the fittest”

And eventually, everyone would be used to seeing three legged ducks So animals such as this Should not be so unusual after all

Passing the mutations along Mutations that happen in sex cells (eggs and sperms) during meiosis will be passed along to offspring (children) Mutations that happen in somatic or body cells during mitosis will NOT be passed along to offspring

Recombination of Traits From Parents Sexual Reproduction Some people's hairlines come to a V-shaped point above their forehead. This is called a widow's peak. Do you have one or not? What do your parents have?

Natural Selection

Natural selection – is the engine that drives evolution! The organisms best suited to survive in their particular circumstances have a greater chance of passing their traits on to the next generation. Plants and animals interact in complex ways with other organisms and their environment; like this hummingbird and flower which have evolved to be perfectly suited to each other for pollination! This is how we get amazingly diverse range of life forms on Earth!!

Asexual Reproduction Vegetative

Budding the production of offspring that are genetically identical to the parent organism only one parent involved does not provide any genetic variation among individuals of a species maintains beneficial traits in all offspring generally used by less complex organisms 1 The hydra develops a "bud". 2 The bud develops a mouth and tentacles 3 When it is fully formed the daughter hydra detaches from its parent. 4 The daughter hydra is now fully independent.

Binary Fission a.k.a. Mitosis Mother Cell splits into Two Daughter Cells Each daughter cell is identical

Spores A spore is a structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many plants, fungi and algae. A chief difference between spores and seeds is that spores have very little stored food resources.

Survival of The Fittest! Depends on how successful the organism is when competing for: mates, food, habitat, RESOURCES Whose genes will survive to carry on the ‘fittest’ traits? Who is best adapted to compete for resources?

What does fittest mean? Is it faster? Is it stronger? Is it prettier? Is it smarter Is it nicer? Is it helpful to others? Is it meaner? Is it bigger?

Natural Selection Selection = choosing traits (physical and behavioural) that give an organism an advantage in a particular niche Natural = ???????????????????????? THE ENVIRONMENT!!!!!!!!!!!!!!!!!!! So what’s doing the selecting or choosing? THE ENVIRONMENT!!!!!!!!!!!!!!!!!!!

rapid evolution in bacteria A mutation can occur in bacteria that gives the affected bacteria Immunity to antibiotics … that’s why sometimes your infections Do not respond to antibiotic treatment Pneumonia is an infection of your respiratory tract with bacteria that multiply like crazy and destroy your ability to breathe Pneumonia used to kill thousands … before antibiotics were discovered HOWEVER