biology review
DESCRIPTION
First lecture for Drury Ava Campus Spring 2010TRANSCRIPT
ZoologyZoology
Review of Biology concepts.
The Science of ZoologyThe Science of Zoology
Zoology is the study of animal life.
Classification
Taxonomy
Systematics
Linnaeus and Classification
Carolus Linnaeus designed our hierarchical classification scheme.KingdomPhylumClassOrderFamilyGenusSpecies
Linnaeus and Classification
Binomial nomenclature is the system Linnaeus used for naming species.Genus and speciesNames are latinized and italicized, only the
genus is capatilized.Sitta carolinensis
Linnaeus and Classification
A trinomial name includes a subspecies epithet. Ensatina escholtzii
escholtzii E. e. klauberi
Species
The Science of ZoologyThe Science of Zoology
Entomology Herpetology Ichthyology Mammalogy Ornithology
Fundamental Properties of LifeFundamental Properties of Life
Does Life Have Defining Properties?What is life?
Environmental InteractionEnvironmental Interaction
Ecology is the study of this interaction between organisms and between organisms and their environment.
Prokaryotic vs. Eukaryotic Cells
Components of Eukaryotic Cells
Cytoskeleton
Microtubules tubulin.
Biological Hierarchy
Evolution and HeredityEvolution and Heredity
1. Darwin’s Theory of Evolution
2. The Chromosomal Theory of Inheritance
Mendelian HeredityMendelian Heredity
Gregor Mendel performed experiments on garden peas leading to an understanding of how chromosomal inheritance works.
Mendel’s PeasMendel’s Peas
Darwin’s Revolutionary Theory
Pre-Darwinian Evolutionary Ideas
Jean Lamarck
Empedocles
Aristotle
Uniformitarianism
Charles Lyell’s Principles of Geology
The Voyage of the Beagle
The Voyage of the Beagle
Alfred Russell Wallace
After the Voyage
Theory of EvolutionTheory of Evolution
Natural Selection
Artificial Selection
Fossils
The Fossil Record
Homologous structures
Vestigial Organs
Unity in DiversityUnity in Diversity
All mammalian forelimbs share an underlying structure utilizing the same parts, but have evolved a diverse array of adaptations, as seen in the wing of a bat, the flipper of a whale, & a human arm.
Sorting Homology from Analogy
Phylogeny
cladogram
Phylogeny
Tree of Life
Populations Genetics
A prime example of an exuberant polymorphism is the Hawaiian Happy-face Spider, which has been studied by Dr Geoff Oxford and colleagues. (Photo Credit: Image courtesy of University of York)
Populations
Where Does Variation Come From?
Two processes provide the variation in gene pools.MutationSexual recombination
Gene Mutations
Sexual Recombination
Genetic Drift
The Bottleneck Effect
The Bottleneck Effect
http://www.sealexperience.com/index.html
The Founder Effect
Gene Flow
Modes of Selection
Stabilizing
Directional
Disruptive
Genetic Variation
Polymorphism
Allopatric Speciation
Parapatric Speciation
Sympatric Speciation
Ecological Niche
Habitat Ecological Niche
Generalists - Broad nicheSpecialists - Narrow niche
Resource PartitioningLaw of Competitive Exclusion
resource partitioning
radiative evolution
Levels of Organization
Levels increase in complexity as the numbers and interactions between organisms increase.
Energy in an Ecosystem
Autotrophs
Heterotrophs
A lynx is a heterotroph.
SPECIES INTERACTIONS
predator – prey
Co-evolution
Competition
Interspecific
IntraspecificTerritoriality
Symbiosis
SymbiosisCommensalism MutualismParasitism
Symbiotic Relationships
Mutualism
Commensalism
Parasitism
That’s All Folks
Major Divisions of Life
Aristotle’s two kingdom system included plants and animals. One-celled organisms became a problem
Haeckel (1866) proposed Protista for single-celled organisms.
R.H. Whittaker (1969) proposed a five-kingdom system to distinguish prokaryotes and fungi.
Major Divisions of Life
Major Division of Life
More revisions are necessary to clarify taxonomic kingdoms based on monophyly.
“Protozoa” Neither animals nor a valid monophyletic taxon.
“Protista” Not a monophyletic kingdom. Most likely composed of seven or more phyla.
Major Subdivisions of the Animal Kingdom
Traditional groupings based on embryological and anatomical characters:
Branch A (Mesozoa): phylum Mesozoa, the mesozoa
Branch B (Parazoa): phylum Porifera, the sponges and
phylum Placozoa
Branch C (Eumetazoa): all other phyla
Sexual Selection
Sexual dimorphism
Intrasexual Selection
Intersexual Selection
Reproduction
Asexual Reproduction
Asexual Reproduction
Asexual Reproduction - Advantages
Sexual Reproduction
Parthenogenesis
Parthenogenesis involves the development of an embryo from an unfertilized egg or one where sperm & egg nuclei did not fuse.Ameiotic parthenogenesis – no meiosis,
egg is formed by mitosis (diploid)Meiotic parthenogenesis – haploid ovum
formed by meiosis, it may be activated by a male (or not).
Parthenogenesis
In some animals (aphids, rotifers, Daphnia) the females can produce two types of eggs.One must be fertilized.One type will develop directly into haploid
adults – parthenogenesis.Haploid females produce eggs by mitosis.
Parthenogenesis
Daphnia reproduce asexually (parthenogenesis) when conditions are favorable.
In times of environmental stress, they utilize sexual reproduction. Increases variation!
Parthenogenesis
In many social insects, like honeybees, males (drones) are haploid and are produced by parthenogenesis while females (workers & queens) develop from fertilized eggs.
Parthenogenesis
Parthenogenesis occurs in vertebrates in some fishes, amphibians, and lizards.After meiosis, the chromosomes are
doubled, creating diploid “zygotes”.Often mating behavior is required to
stimulate development of offspring.
Hermaphroditism
Hermaphroditism occurs when an organism has both male and female reproductive systems. Monoecious Some can fertilize
themselves. Usually a mate is
required – they can fertilize each other.
Sequential Hermaphroditism
In sequential hermaphroditism, an individual reverses its sex during its lifetime. In wrasses, sex reversal
is associated with age, size and social conditions.
Fish are female first. The largest female
becomes male if the previous male dies.
Sequential Hermaphroditism
There are also sequential hermaphrodites that are male first, later changing to female.
This occurs in species that produce more eggs at a bigger size – so it is advantageous to have larger females.Oysters
Fertilization
Fertilization – fusion of egg and sperm into a single diploid cell, the zygote. External Internal
External Fertilization
External fertilization – fertilization takes place outside the female’s body. A wet environment
is required so gametes don’t dry out and so sperm may swim to the eggs.
External Fertilization
Environmental cues (day length, temperature) or chemical cues may cause a whole population to release gametes at once. Increases likelihood
of fertilization.© 1999 New World Publications.
http://www.fishid.com/learnctr/corspawn.htm
Internal Fertilization
Internal fertilization allows terrestrial animals to reproduce away from water.Cooperative behavior leading to copulation
is required.
Ensuring Survival of Offspring
Species with external fertilization produce huge quantities of gametes that result in lots of zygotes.Predation on young is high.Few will survive to reproduce.
Ensuring Survival of Offspring
Species with internal fertilization produce fewer zygotes, but protect them more from predation. Tough eggshells Embryo may develop in
reproductive tract of female
Parental care of eggs & offspring
Advantages of Sexual Reproduction
Sexual reproduction has costs including finding mates, greater energy cost, reduced proportion of genes passed on to offspring, and slower population growth.
However, sexual reproduction increases variability in the population – important during times of environmental change.
Gamete Production & Delivery
Gametes (eggs & sperm) are required for sexual reproduction.
Usually, gametes are produced in gonads (ovaries & testes).
Germ cells are set aside early in development. They will produce only gametes.
Reproductive Patterns
Oviparous – animals that lay eggs. Most invertebrates, many vertebrates
Ovoviviparous – animals that retain the eggs within their bodies. Nourishment comes from the egg. Some annelids, insects, some fishes, reptiles.
Viviparous – eggs develop in oviduct or uterus, nourishment from mother. Mammals, some sharks, scorpions.
Invertebrate Reproductive Systems
Many insects have separate sexes, internal fertilization and have complex reproductive systems. Female crickets use
long ovipositors to deposit eggs.