Diversity of Life and Evolution - Biology 30 Unit 5

Panspermia

The theory that life originated somewhere else in the universe and travelled to earth via meteors.

Oparin-Haldane hypothesis

Life arose gradually from inorganic molecules, with "building blocks" like amino acids forming first and then combining to form more complex polymers.

Evolution

Change in the gene pool over time, change in heritable characteristics of populations over time.

Evolutionary Adaptations

Evolutionary process of natural selection that fits organisms to their environment, improving their evolutionary fitness, and it's the mechanism by which organisms adjust to their environments.

Theory of Evolution

Process of change in all forms of life over generations, the frame work that explains the mechanisms driving change

Theory of the Earth

Publication by James Hutten which showed that the earth is a process of natural forces. What we see happening today, over long periods of time, could produce what we see in the rocks.

Uniformitarianism

The idea that the Earth has always changes in uniform ways and that the present is the key to the past.

Inheritance of Acquired Characteristics

Also called lamarckism, idea that an organism can pass on physical characteristics that the parent acquired through use or disuse throughout its lifetime.

Natural Selection

A mechanism of evolution. Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided them in their success.

Descent with Modification

The process used by natural selection. As traits are passed on through generations, there is modification. It's a change in the heritable information passed through generations.

Theory of Mutation

Idea that new species are formed through sudden and unexpected emergence of alterations in their defining traits.

Modern Synthesis

Integration of Darwin's theory of evolution with mendelian genetics, forming modern evolutionary theory. New definition of evolution of "the changes occurring in the allele frequencies within the populations" which emphasizes genetic basis of evolution.

Microevolution

The changes in gene frequencies in a population over a relatively short period of time.

Macroevolution

Large-scale evolutionary changes that occur at and above the species level.

Extinction

The complete disappearance of a species from earth.

Plate Tectonics

The scientific theory states that earth's outermost layer, the lithosphere, is divided into rigid plates that move and interact with each other, driven by heat from beneath the earth's surface.

Continental Drift

The theory that earth's continents have moved over millions of years, and are still moving, to their current positions.

Fossil

The preserved remains of plants and animals whose bodies were buried in sediments.

Relative Dating

The science of determining the relative order of events, without actually determining their exact age.

Radioactive Dating

A method of dating rocks and minerals using radioactive isotopes.

Derived Traits

Those that just appeared in the most recent ancestor, and began a new branch.

Ancestral traits

Traits that were inherent in the common ancestor of a group of species, and has been inherited by all descendants of that ancestor.

Comparative Anatomy

The study of the similarities and differences in the structure of different species.

Homologous structures

Body parts in two species that have the same common ancestor and have a similar underlying structure, but serve a different function.

Analogous Structures

Features in two different species which share the same function, but do not have a common ancestor or similar structure.

Vestigial Structures

Features which were useful to an organism's ancestors but have lost much or all of their function through evolution.

Comparative Embryology

Compares and contrasts the embryo and embryonic development of different species, showing how all animals are related.

Molecular Biology

Branch of biology which seeks to understand the molecular basis of biological activity in and between cells.

Homologous Genes

A type of gene that is inherited by two different species and evolved from the same ancestor.

Biogeography

The study of the distribution of species and ecosystems through in geographic space and through geological time (how they are distributed throughout the landscape through time and space)

Taxon cycle

A biogeographical theory describing how species evolve and change over time through expansions and contractions of their ranges, often linked to adaptive changes in their morphology and ecology

Theory of Island Biogeography

A 1967 book by ecologist Robert MacArthur and biologist Edward O. Wilson. It predicts that the number of animal and plant species on an island is related to the island's landmass and the degree of isolation of the island. The theory states that smaller, more isolated islands have fewer numbers of plant and animal species.

LUCA

Last Universal Common Ancestor, is the last node on the tree of life from which the fundamental domains of prokaryotic organisms (archaea and bacteria) diverge.

Gradualism

Theory or process in which species experience evolutionary changes slowly or through long increments and periods of time.

Punctuated Equilibrium

The idea that evolution occurs in spurts instead of slowly and over long periods of time. Long periods with little activity will be interrupted by sudden bursts of change, as proposed by Darwin.

Behavioral adaptation

Actions or behaviors that an animal exhibits to increase its chance of survival in a particular environment.

Taxis

The directional movement of an organism in response to a stimulus, can be positive (towards) or negative (away from).

Tropism

The turning of all or part of an organism in a particular direction in response to a stimulus.

Structural adaptation

Adaptations that change the physical features of an organism.

Physiological adaptation

The internal body processes and mechanisms that enable organisms to survive and thrive (to maintain homeostasis) in their specific environment.

Divergent Evolution (Adaptive Radiation)

Process where a single ancestral population evolves into multiple diverse species as they adapt to their environments.

Convergent Evolution

The process whereby distantly related organisms independently evolve similar traits to respond to similar necessities or environmental pressures. Species become more similar to unrelated species, which leads to unrelated but similar species

Coevolution

Two species reciprocally effect each other's evolution.

Predation

One organism kills and eats another.

Interspecific Competition

The competition between individuals of different species.

Parasitism

One organism, the parasite, lives on or in another and benefits at the host's expense.

Ectoparasite

Parasites that live on the external surface of hosts.

Endoparasite

A parasite that lives on the tissue and organs of its host.

Mutualism

A relationship between two or more species where each species benefits from the interaction.

Commensalism

A symbiotic relationship where one organism benefits while the other is neither harmed nor helped.

Mechanical digestion

The physical breakdown of food into smaller pieces, primarily through chewing, to increase surface area for chemical digestion.

Chemical digestion

The process of breaking down food into smaller, absorbable units using enzymes.

Extracellular digestion

Process where food breakdown occurs outside the cell, typically with a digestive cavity or lumen, rather than inside individual cells.

Intracellular digestion

Process where cells break down food within their own cytoplasm.

Acoelomate

An animal that has no internal, fluid filled body cavity.

Pseudocoelomate

An invertebrate animal that possesses a fluid-filled body cavity called a pseudocoelom, which is located between the gut and the outer body wall.

Coelomate

Animals that have a body cavity called a coelom, with a complete lining called peritoneum derived from mesoderm.

Diffuse nervous system

Type of nervous system characterized by nerve cells distributed throughout the organism, rather than being concentrated into a centralized nervous system.

Centralized nervous system

Nerve cells concentrated in brain or spinal chord.

Nerve net

A simple, primitive nervous system where nerve cells are interconnected in a mesh-like structure, and can send signals in any direction.

Cephalization

The concentration of sensory and feeding organs such as nerve cells, mouth, and jaws, at the anterior end of the body (towards the front), usually resulting in a larger head.

Ganglion/brain

The basal ganglia is a group of interconnected nuclei deep within the brain stem.

Nerve cord

The major cord of nerve fibers running the length of an animal's that coordinates neural signalling from the brain to the body and vice versa.

James Hutton

• published the theory of the earth

• father of modern geology

• concluded the earth changes gradually, and that geological forces shape it over a long period of time

Charles Lyell

• developed uniformitarianism

• three main principles:

1. natural laws are constant in time and space

2. scientists should attempt to explain past events through the same processes that can be seen today

3. most geological change occurs slowly and gradually, not through catastrophic events

Lamarck

• inheritance of acquired characteristics (develops traits by using or not using them)

• described HOW species evolve

Alfred Wallace

• naturalist and colleague to Darwin

• collected biological samples throughout south america

• said that living things change over long periods of time

Hugo DeVries

• mutations

• researched evening primroses

• new species arise in single, quick jumps

Dobhansky

• developed "modern synthesis" (connected mutations with natural selection)

• father of evolutionary genetics

• studied fruit flies

Wilson

• Tacon Cycle

• Theory of Island Biogeography