Biology Unit 3

• Extinct


  Species have disappeared from Earth completely. The diversity of organisms, their behaviour and their interactions with the environment explain how some species survive and some don't
• Adaptation is the result of

  a process of gradual, accumulative changes that help an organism survive and reproduce. These changes are te result of random, heitable mutations in DNA that accumulate over generations.
• Variations


  Are the structural, functional or physiological between individuals. As it becomes more common it will be considered to be a trait or a characteristic of the population
• Mimicry


  Strucural, harmless species physically resemble a harmful species. This makes predators avoid both the harmful and harmless. (English Peppered Moth)
• English Peppered Moth


  The environment of these moths changed from a light colour to a soot covered black one. The light moths were all caught by their predators while the black ones lived longer and were able to pass this trait to their offspring.
• Mutation


  Permanent change in the genetic material of an organism and is the only source of new genetic variation.
• Selective Advantages


  A genetic advantage that improves an organism's chances of survival and reproduction, usually in a changing environment. It arises from a mutation that has become beneficial. Reproduce quicker > Adapt quicker.
• Gene Pool


  The combination of all the genes (including alleles) present in a reproducing population or species
• Fitness


  An organism's ability to pass its genetic material to its offspring
• What causes variation


  Created by the different combinations of genetic information that offspring inherit from their parents, The original source of all those different alleles is mutation.
• Behavioural Adaptations


  An inherited characteristic behaviour that helps an organism survive in its environment. (Migration/Hibernation)
• Structural Adaptations


  An physical adaptation that helps an organism survive in its environment. (Gills/Legs)
• Physiological Adaptations


  An internal body process to regulate and maintain homeostasis for an organism to survive in the environment in which it exists. (temperature regulation/release of toxins or poisons)
• Drug - Resistant Bacteria

  Since bacteria reproduces very quickly it is easy for it to build up a tolerance against antibiotics. The surviving ones reproduce and pass the alleles to the offspring.
• Selective Pressure


  An abiotic (non-living) or biotic (living) environmental condition can be said to select for certain characteristics in some individuals and select against certain characteristics in others
• Natural selection


  Process of change in the characteristics of a population of organisms over many generations
• Monoculture


  Large area has one type of plant with little genetic diversity
• Artificial selection


  Selective pressure exerted by humans on populations in order to improve or modify particular traits
• Biotechnology


  Modification of organisms to produce useful products
• Evolution


  The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms
• Catastrophism


  The idea that sudden, short-lived, and violent events lead to the extinction of many organisms.
• Uniformitarianism


  Geological processes in the past operate at the same rate as they do today, a slow and continuous process could result in substantial changes in the long term.
• Descent with modification


  Principle that each living species has descended, with changes, from other species, species increased in complexity and became better adapted to their environment over time.
• Survival of the fittest


  Individuals that are better suited (fitted) to local conditions survive to produce more offspring.
• Paleontology


  Founded by, Georges Cuvier. Mary Anning contributed to this field greatly.
• Drawins theory


  Theory of natural selection: how life has changed and continues to change, due to natural pressures, the first comprehensive presentation of the idea. (The flora and fauna were different in different regions/Finch beaks were adapted to the food source on each island)
• Lamarcks theory


  line of descent
• Inheritance of acquired characteristics


  Characteristics acquired during an organism's lifetime

  could be passed on to offspring
• Cuvier and Wallace theory


  Catastrophism: Discovered that each stratum (layer) of rock held a unique group of fossil species, discovered that the oldest fossils are in the deepest layer. Wallace made a similar theory to Darwin's
• Vestigial structures


  Structures that have no apparent function and appear to be residual parts from a past ancestor
• Biogeography evidence of evolution

  Geographic distribution of species. Fossils of the same species can be found on the coastlines of neighbouring continents. (When Gondwana the super split the animals on the coastlines of the new continents were similar).
• Homologous Structures (Anatomical evidence of evolution)


  Those that have similar structural elements and origin but may have a different function. They originate from a common ancestor.
• Analogous structures(Anatomical evidence of evolution)


  Do not have a common evolutionary origin but perform similar functions. These provide evidence for adaptation to suit the environment. An example is the fins of a porpoise and a fish.
• Embryology


  The study of pre-birth stages of an organism's development. It has been used to determine evolutionary relationships between animals
• Transitional fossils


  Any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group. Show an intermediary link between past and present groups of organisms.
• Fossil Evidence of Evolution

  Fossils in younger rock are more similar to current species than those in deeper strata. Fossils appear in "chronological order" in the rock strata, and probable ancestors of a species are found in older rocks. Not all organisms appear in the fossil record at the same time, showing the successive evolution of groups (kingdoms) of species.
• DNA evidence of Evolution


  Evolutionary relationships are reflected in DNA since DNA carries genetic information from generation to generation: Species that have similar DNA share a common ancestor. DNA evidence supports conclusion about relationships and common ancestry provided by other areas of evidence.
• Homologous vs Analogous


  homo- structures share a common ancestry

  ana- structures are nor inherited from a common ancestor, but perform similar functions
• Which strata hold older vs new fossils

  Younger strata closer to the surface contain newer fossils.
• Gene flow


  Describes the net movement of alleles from one population to another as a result of the migration of individuals. (Grew wolves will often travel to find a neighbouring pack and math with an individual in that pack. This brings new alleles into the distant pack and may change allele frequencies and increase genetic diversity.)