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.